Showing posts with label maintenance. Show all posts
Showing posts with label maintenance. Show all posts

Saturday, August 29, 2020

Cayman S Water Pump

 I did a dumb thing but it turned out OK.  When I took the Cayman out of winter storage this spring and warmed it up for the first time in a while, I smelled coolant, although none leaked to the ground.  I have seen water pump seals do this before.  On most older cars the water pump has a simple bushing that runs in coolant so a small seep that quits is not necessarily a big deal.  My F250 would do this on severe cold weather but never had a pump failure.  However, the Cayman water pump is not like that.  It has a sealed roller bearing instead, which is far better and should last for life.  However, if you get coolant seeping through the bearing, the bearing will die pretty fast.  The grease will get washed out, the bearing will run dry, and fail.  Well, that is what happened to me.  I had noticed a growling noise from the engine when I started it that morning.  My first thought was far worse than a water pump.  I feared my IMS bearing was going out.  After recalling that I did see dry evidence of coolant from the water pump I sorta convinced myself it could just be some coolant on the belt, which can make all sorts of weird noises.  Honestly I was not that convinced, I was just lazy and in a hurry to meet with some friends.  

On my way back from breakfast where I was meeting with friends I heard a pop and immediately my steering assist was gone and the charging system warning came ON.  Right away I knew I had lost the belt.  I carefully drove the rest of the way home, accelerating moderately up to speed, shutting OFF the engine, and coasting between lights.  By the time I got home the coolant temp was a bit over 200F based on the gauge.  Still safe but I would not want to get it too much hotter.  With no belt, the coolant does not circulate.  You can't go very far like that.  In the video below you can hear the pop right at the beginning.

It is not real loud and I did have the stereo going.  I quickly turned OFF the AC and opened the windows too.  

Once I was home, I removed the panel behind the seats to expose the front of the engine where the belt and water pump are.  I saw the slack belt but upon further inspection I found the water pump shaft had completely sheared off and the pulley was just laying there.


Glad to see it was just a water pump, I quickly ordered parts through the local dealers online website. 

  

Mid-engine cars have a much trickier cooling system since the engine is in the middle, and the radiators are in the front fenders ahead of the wheels.  This makes it an air pocket nightmare.  A vacuum system is needed to pull a vacuum on the cooling system and suck the coolant in.  I found this one on Amazon for $39.99.


Having the engine behind the driver and not even visible without removing bolt-in panels and carpet sounds like jobs like this would be much harder.  However, it is not too bad really.  It takes about 15 minutes to remove the carpet section and both the top engine panel, and the front engine access panel. Once you have these panels off, access is pretty good for most things.  I will say charging the water pump on this car is far easier than most front-wheel-drive cars.  

I positioned the car on a ramp on the drivers side, and jacked up the passengers side as high as my jack stand would allow.  This positioned the coolant reservoir as high as possible relative to the car. I did this to keep the radiators and heater core full of coolant making it easier to ensure all the air was out when I was done.   

I started by clamping the radiator hose and one of the heater hoses.  

I loosened the hose connected to the water pump at the bottom and stuck an Allen wrench in it to allow the coolant to drain in a more controlled fashion.  In this position, and with the clamps in place, about 2 gallons of coolant drained into the pan I had to catch it.  I then removed the water pump.  It is basically just a set of small bolts.  The nice thing is the gasket is metal and does not stick to the block so it left a clean surface.  Here is a photo with the pump removed.



  When installing the new pump, make sure the longer bolts are in the correct holes, with the alignment dowels.  Here you can see the new and old pumps, both showing the alignment dowels.

Here is a photo with the new pump installed.

Before removing the hose clamps, I drew a vacuum on the cooling system and pulled in the coolant.  

I was able to pull in almost 2 gallons right away.  Remember to open the air bleed valve in the top of the reservoir to allow the air to escape the block while doing this.  I then released the clamps, installed the belt, and ran the engine.  With the engine running I could feel more air purging through the air bleed hose that connects from the oil cooler to the reservoir.  I added about a quart more coolant at this point. I ran the engine some more until I could feel the heater hose warm up, indicating I was getting coolant flow.  I ran the engine until the thermostat opened and I could feel the radiator hose at the radiator warm up, indicating flow to the radiators. I did all of this while the car was still raised.  I took it for a good road test, hitting 7,000rpm at times to create high coolant flow and purge any remaining air.  

The whole job took me about 3 hours.  Not too bad.  


Tuesday, December 26, 2017

2006 Porsche Cayman S 80k mile review


I bought this Cayman S in 2014 and wrote an article about the buying experience and first impressions.  Recently this car hit 80k miles (actually just under but close enough) so I would I would write a review of what it has been like since I bought it.  This is my second Porsche.  The first was a 1987 944S.  This car is a huge upgrade in every way.  This is the best car I have owned, especially from a driver engagement perspective.  When you first get in you already know you are in a very special car.  Often when I am at the gas station filling up I get compliments on the car.  When you start up the flat 6 in the morning it rumbles for a bit as the catalyst warm-up strategy makes for a lopey idle that sounds great.  I have done just a couple minor modifications, 2 of which improved the engine sound.  The first was to replace the restrictive exhaust outlet.  The second was removing the baffles from the air box and installing a K&N filter.  Now you can really hear the sweet induction sound which is hard to describe with words.  I drive the car daily as long as there is no salt on the roads (which takes out most of the winter).  I also give it proper exercise by doing a few track days each year.  On the street you find that you don't even need to brake where you would with mortal cars.  The cars ability to effortlessly change directions is pure magic.

The Good

Pretty much everything!  
  • World class leading handling.  Confidence inspiring.  I can't properly describe the feel of this car in words.  You must drive one to understand (not recommended unless you are ready to buy one).  It feels more like a streetable race car then a raceable street car.  
  • Awesome looks.  You can see both form and function in this design.
  • Mid-engine behind driver design.  Did I mention how well this handles!
  • Great engine.  Sound is amazing and power is also good.  Sure, I could always make use of more power but I don't find myself pining away for it.  As you hold the throttle open you can hear the cams phase and open up the flow.  When you upshift at redline you get this incredible wail that reminds me of the F1 cars in the V8 days.  
  • Comfortable seats.  I have the standard seats (versus the sport) and even these are great.  Its easy to get in and out yet they still hold you well at the track.  
  • Practical spaces to carry stuff.  With 2 trunks you actually have good space to carry stuff for a sports car.  
  • Excellent dash and gauges.  All the info you need at a glance.  The analog speedo is a bit less useful but the tach and display are perfect.  
  • Great interior.
  • The ride is spot on.  A bit firm on rough roads and it could use a bit more firmness on the track but this is a great middle ground.  Its firm but not jarring on rough Midwest roads yet still great at the track.  I don't have the active shocks (PASM) and that would likely improve this even more at the track.
  • General ergonomics.  Everything is where it belongs and is intuitive to use.  
  • Very simple to change brake pads.  With fixed calipers you just pull a pin and the pads come right out.  This is more important when you tack it as you change pads often.  
  • I can comfortably fit with a helmet on.
  • The seats go low enough.  In most cars it feels like you sit far too high.  This one lets you lower the seat down where it should be.
  • Great automatic HVAC.  Automatic HVAC systems are not created equal.  This one however works very well.  I set it and forget it.  
  • Sport Chrono sport mode.  My car has the Sport Chrono system.  While I don't really use the timer, part of this feature in this car is a sport mode for the engine and traction control.  This makes the throttle response crisper, changes to a hard rev limit, and relaxes the traction control nannies so you can have more fun while still not crashing.  
  • You don't have to waste money making your engine look good because nobody can see it anyway.  It runs and sounds fantastic and that is what really counts.
  • Fuel economy.  Around town I often get over 20mph even with my lead foot and short drives.  At the track I can go 4 sessions on a tank of fuel which is great.  The highway fuel economy is less good, around 26mpg.  If this car had a 7th gear it would likely do well over 30mpg.  At 75mph it is running at 3,000rpm.  Fuel economy is certainly not the focus of this car.

Gripes

This is a short list of minor whining.
  • Every other car now feels less good.  The bar has been raised very high and other cars that you once really liked are now below the bar.  
  • Crankcase breather issue.  Occasionally at the track it will carry oil over into the intake.  At times this causes smoke on start up.  I have only had this happen a few times and only at the track.  I may have overfilled it as well.  There is a motorsports breather available that fixes this.   
  • I cannot reset the oil change reminder without buying expensive tools.  
  • A weak battery can cause the body control to reset to factory defaults.  You have to go to the dealer to get features re-enabled.  Never let the battery get run down.  Keep a maintainer on it when storing.  Keep a fresh battery in it.
  • No radiator grilles.  There are many fixes for this.  Mine is in this article: https://jimroal.blogspot.com/2015/05/porsche-cayman-s-grilles.html

Maintenance & Repairs

Overall this is a very reliable and durable car.  I don't drive it easy either.  It is also surprisingly easy to work on.
  • Tires.  Since I do track days its rare tires make it 15k miles.  Nothing wrong with the car here.  Cost of the tires are actually what I consider reasonable.  I can get the top of the line Michelin Pilot Super Sports for under $1k.  I have the 18" rims.  For the track more negative camber is needed and you should also set the toe to 0.  I did a crude adjustment and the tires now wear better at the track.
  • Brakes.  Like tires, brakes will go fast if you do track days.  Good pads for this car cost about $200 per axle set (or $400 all around).  Again, these are good pads.  I'm sure you can find cheaper pads but never try to save money on brakes by going with poor quality.  I generally use Hawk pads.  I do have a street set and a different set for track.  More on brakes here.
  • Oil & filter.  This is very simple to do at home.  I back the car up on ramps.  The filter and drain plug are right next to each other.  It takes 8.5 quarts of Mobile One 0W-40.  Oil change costs about $80 to do at home.
  • Spark plugs.  When I first got this car I thought engine access would be a challenge but really it is not.  Changing the plugs involves removing the rear wheels and a small plastic panel.  After you do that you can easily see all the coils.  Its not hard at all.  
  • Interior rattles.  After 80k of Midwest crappy roads and track days it did develop a couple rattles.  One was around the drivers door speaker which I fixed by removing the door panel and tightening everything up.  Another was with the third brake light assembly in the hatch.  Again, I removed the hatch interior panel and tightened everything up.  Another was in the right rear speaker area, again removing trim, tightening stuff.  
  • Catalyst DTC.  When I bought the car with 60k miles it had a DTC for catalyst efficiency failure.  I addressed this by moving the HEGO for now.  I would like to upgrade to some good headers which will also correct this.  The efficiency fault just means it is not fully catalyzing the exhaust.  It does not cause any other problems.  This is likely doe to a crankcase breather issue causing oil carry-over.  That breather assembly was replaced just before I bought the car.
  • Battery.  Normal cost and easy to change.
  • Hood struts.  Typical cost and easy to change.  
  • Brake light switch.  Typical cost and easy to change.
  • CD Changer failed.  Who cares.  You have a wonderful flat 6!
  • Clean the radiators and install grilles.  Without grilles the radiators collect every leaf and rock they can find.  Mine were probably 50% plugged yet the car did not run hot.  Of course, I cleaned them before I went to the track.  
  • Starter noise.  I just replaced the starter.  It was under $200 for a reman and simple to change.  
  • Weak battery caused the body control to reset to default.  I had to take it to the dealer for an initialization procedure which involves connecting the service tool and enabling the features for the car.  It cost me $70.  Until I had that done my heated seats and garage door opener would not work.

Sunday, December 24, 2017

Mercedes E350 4matic first 100k miles

We bought a 2010 E350 4matic in the summer of 2015 with 34k miles on it.  Usually I search a wide radius and spend weeks looking for cars but in this case, it was the 2nd one we drove and we bought it only a few miles from our house.  I would have preferred red or blue but this car looks pretty good in silver in my opinion.  I think this is the best looking Mercedes sedan.  It is sportier looking than the S-Class in my opinion, but I would be open to an S-Class too.  This was the first Mercedes we ever owned but it will likely not be the last.  IN fact, we are shopping for another right now but we will also keep the E350.  I wanted to share our experience with this car after it passed 100k miles.  Actually it has 105k on it as I write this.  We have a 500 mile drive to visit our daughter that we make several times a year.  About 1/3 of the miles we put on this car are trips to see her.  The rest are normal mostly in-town miles.  We get all the seasons here including snow and ice.  Would I buy one again?  Heck yeah!  This has been a great car and I would highly recommend it to others.  These cars are a bargain as used cars.  They drop fast so you can pick up one with low mileage and only a few years old for less than half of new.  You can even find Certified Pre-Owned (CPO) for around half of new with a factory extended warranty.

Driving Impression

We have owned many cars over the years but this is the best overall car.  Driving the 500 mile trip as we often do leaves the driver with no fatigue.  The car inspires confidence and this makes for a low stress driving experience.  For a car of this size and weight it handles very good.  High speed driving feels comfortable and controlled.  Navigating through tight traffic is also as good as it gets.  The 4matic works well in poor traction conditions such as snow and ice.  With 105k on the car it honestly drives exactly the same as when we first got it.  I can get 27mpg on the highway at times, even when averaging over 70mph for the trip (which includes in-town driving).  We get about 20mph in town.  I am quite happy with that.  The engine has acceptable power for the car.  I would prefer the E63 AMG of course but it would be wasted on my wife and this is her daily driver.  

The Good Stuff

This has been a great car overall.  I would buy another in a heartbeat. 
  • Virtually non-existent driver fatigue even on long trips in bad weather, which we do often.
  • Excellent entertainment system with a dedicated volume knob.  By far the best way to control volume is a good old knob you can feel. The system are an AUX input and you can add an SD card adapter with in the dash.  It also had a hard drive you can store music on.  It has satellite radio built in for those who want that (which is not me by the way).  I wish it had Android Auto but it was built before that was available.
  • Excellent controls for the navigation and entertainment system.  The knob control is FAR better than a touch screen.  It is easy to control with one hand while keeping your eyes on the road.  Much less distracting that a touch screen that you have to look at.  
  • Great design of the center console door.  It is split in half and opens to each side.  This is far better than most than have a single hinge.
  • Great backup camera.
  • Excellent 4matic all wheel drive.  This system is full-time AWD with a center differential which is far superior to the automatic engaging part time AWD in most cars.  This system mechanically prevents loss of traction instead of just reacting to it.  It also has stability control to further enhance the system.
  • Paddle shifters.  The shifters have a great feel and short throw.
  • Transmission controls.  I actually like the Mercedes lever for selecting forward, neutral, reverse, and park.  It is out of the way and simple to use.  It is different than other cars and takes some getting used to.  It clears the console for drink holders and the drink holders are in exactly the right spot.  In most cars the shifter gets in the way and the drinks end up in an odd spot.
  • Entertainment display.  I love the way the entertainment display is placed in the dash like it actually was designed for it.  Many new cars have this ugly tablet looking thing sticking out of the dash like it was and afterthought or aftermarket.  Also, I like that it is not a touch screen.  The controls are far superior to a touch screen and the screen remains clean.  
  • Hook for grocery bags in trunk.  This is a small but awesome feature to keep your groceries from flailing around in the trunk.  Nets are OK but this hook is far better.  
  • I can reset the service reminders myself without any tools!  This is a great feature missing from most cars these days.  Honestly I am surprised Mercedes would do this.  I do my own service and I need to be able to reset the maintenance reminders myself and this car has a way to do that using only the steering wheel buttons.
  • Engine access is very open.  I replaced the spark plugs and this is the easiest car I have ever changed plugs on.  The air cleaner assembly comes off with no tools and you can then see all the coils in plain sight with open access.  Most modern cars have the engine tucked so deep under the windshield that you can only see half the engine.  
  • Ride.  This car is a great compromise between smooth ride and good handling.  It is serene even at high speeds.  Very low road noise.  You can have a conversation at a whisper while going 90mph even on crappy Midwest roads.  It handles fantastic for a car of this size and weight.  
  • Cruise control.  Mercedes did a great job with the cruise control.  You can easily see your set speed on the speedometer.  The simple lever has 2 detents for up (accelerate) and down (decelerate).  Clicking in the first detect changes the set speed by 1mph.  Clicking to the 2nd detent however takes you to the nearest 5mph point.  For instance, if you are going 72mph and you click it up to the 2nd detent once, you will go to 75mph.  If you clicked it twice to the 2nd detent you will go to 80mph.  
  • The trip computer. It has an automatic trip computer feature that tracks your trips automatically.  It makes some assumptions about what constitutes a trip and it is pretty good.  You can of course manually start your trips too if you want.
  • Everything in the car requires little effort to operate.  It is a great car for older folks or people with arthritis because of this.  

Gripes

This is a short list but, as with most cars (Porsche Cayman excluded) there are a few things that could be better.

  • Seats.  The seats are very comfortable except for the fake leather.  I think you can get real leather as an option and I would.  While the fake leather does not wear at all, if does not feel good when wearing shorts and it gets hotter than real leather.  Perforated leather would be a great upgrade here.
  • Drivers side blind spot.  The drivers side mirror is small and leaves a big blind spot.  I added a small convex mirror to correct this.  Very simple fix but Mercedes should have dealt with this in my opinion.  Some models has the blind spot warning system which would also be good.
  • Transmission.  The transmission shifts to a high gear and holds it to the bitter end.  This is actually very common with newer cars.  They do this to optimize fuel economy but it makes the car feel sluggish and jerky at times.  The worst part is merging on from a long ramp such as a cloverleaf.  The transmission shifts all the way up and then when you step into it to merge there is no power and a big delay in downshifting.  Here is where I use the paddle shifters to manually lock a lower gear.  Speaking of the shifters, they seem to be a mere suggestion rather than a command.  Sometimes there is a delay between requesting a lower gear and actually getting it.  Under certain conditions such as requesting an upshift when going downhill, it ignores you all together even when the RPM will still be well below any concern level.  The transmission can occasionally have a jerky downshift.  This improved dramatically after having the fluid and filter changed though. 
  • Headlights.  They are fine except I got used to HIDs in my Jaguar and Porsche and my E350 does not have the HID option.  You can get the E-class with HIDs and I would highly recommend it.  You can also retrofit HID which I may do.  
  • Cruise control braking.  OK, many would call this a feature but I am not a fan.  If your speed exceeds the set speed of the cruise control by too much, the car will actually apply the brakes to get the speed back down.  I would prefer it not do this under most conditions.  We live in the flat land but in mountains you would actually want to downshift for this, not apply the brakes.  My use case on the flat land is when passing with the cruise set.  I accelerate to get around and then once I am back in the right lane I release the throttle to allow the cruise to resume.  This braking feature kicks in and slows me down rapidly which is not necessary or welcome.  It is easy to just disengage the cruise to pass, then re-engage it after your speed get back to the cruise set speed.
  • Seat lumbar controls.  Actually I have this same issue with many cars lumbar controls.  They are not very intuitive and it seems challenging at times to get them set right.
  • The entertainment system lacks Bluetooth A2DP (music streaming).  It's crazy how many cars lack this still.  A2DP has been around for a long time before this car was built.  Flip phones supported it back in the eary 2000's yet this 2010 does not support it.  Stupid.  It does have Bluetooth hands-free for phone calls and that works fine.  It also has a port in the glove box where you can connect all sorts of things such as USB and 3.5mm jack with the right adapters.

Repairs & Maintenance

So far this car has been one of the most reliable cars I have owned.  It is also easy to maintain.  While this is the first year of the W212 E-class it is a very reliable and durable car.   
  • The biggest maintenance cost with the exception of tires has been the transmission service which cost me $433 to have done at a local shop. The dealer wanted over $700.  Mercedes recommend this every 40k miles which seems excessive.  The fluid is an expensive synthetic which is actually good for life but they recommend changing it due to clutch material building up in the fluid.  My Jaguars used a Mercedes transmission too and back then they claimed they did not ever need a fluid change.  I had a problem with my XJR at 120k miles because of debris in the fluid so I know why they want it changed.  I changed it at 80k.
  • Spark plugs.  This was very easy to do at home with only basic tools.  I don't think I spent more than 20 minutes on it.     
  • Rear brake rotors and pads.  I have replaced these once due to normal wear.  Parts cost is typical of these components, nothing out of the ordinary and simple to replace. I may not have needed new rotors but I don't skimp on brakes so I replaced them anyway.  I have yet to do the fronts after 105k miles.
  • Tires.  Normal wear item of course and I get decent miles from a set.  Cost is typical for a car like this, $229 each on Tire Rack for the OEM Continentals.  Tires are not an area to skimp on so I do not look for cheaper brands.  I also changed the TPMS sensors when I did the tires.  They were all working fine but I wanted to get new ones with the tires rather than wait for them to have dead batteries.  Cost for these was also typical at $52 each on Tire Rack.
  • Gas cap.  I had the check engine light come on.  I pulled the DTCs and I had 2 evaporative emissions DTCs.  This happened several times and I check to make sure the cap was tight.  It ended up being a leaky gas cap.  Simple and inexpensive fix.
  • Air filters.  These have a bunch of screws to access them but it is still not hard.  There are 2.  Cost is typical of air filters. 
  • Oil changes.  I use the recommended 0W-40 Mobile One oil.  Filter change is simple.  Cost for the whole oil change is about $70 and it is very simple to do.  
  • Drivers lower seat cover tear.  There is a seam that tears on some of these cars over time.  I have a new cover on the way that cost me $229.  I will update with how this goes.
  • HVAC fan motor noise.  It occasionally makes a faint squeaking type noise at certain fan speeds.  This is a common issue in most cars except most cars have enough road noise you don't hear it.  I have one on order for $180.  I will update after I replaced it.
  • Battery.  Typical maintenance item.  Lasted about normal.  Simple replacement.  Typical cost.  

I also posted this review http://jimroal.blogspot.com/2016/12/owning-mercedes-e350-4matic.html after we had the car for a while.  

Sunday, January 11, 2015

Maintaining your own car

I was a professional service technician (mechanic) at a Ford dealer for almost 15 years.  It was my first career.  I went to trade school in Arizona to learn my skills and focused on electrical and electronic systems, driveability, and air conditioning.  I did other repairs as well.  I have some of this experience documented on my website here: http://jimroal.com/repair.html.

I completed a BS in Mechanical Engineering and changed careers in 1998.  However, I still do all my own car maintenance.  I have owned several makes and models over the years.  You can see most of them here: http://jimroal.com/cars.htm.  The only things I take the car into a shop for are tires and alignment since these require machines I prefer not to invest in, although I have considered an inexpensive alignment machine.  I have also made small alignment adjustments at times.  I never buy new cars.  I prefer to let others take the depreciation and pick them up for much less just out of warranty.  I have also purchased cars that still have warranty remaining.  Car reliability follows what is called a "bath tub curve".  There is initial reliability issues early in the cars life.  After those get fixes, your reliability is at its best until wear out.

The sweet spot is somewhere between about 10k miles and 150k miles with modern cars that are well maintained.  I often drive my cars well over 150k miles.  I sold my Crown Victoria and Audi with over 250k miles on them.  I sold my XJR and XJ12 with around 150k miles on them.  Buying a new car means you have a higher probability of needing an unscheduled repair because of infant mortality.  You pay extra for that privilege.  Keeping a car too long means you need to replace parts as they wear out.

If you don't properly maintain your car however, you are asking for trouble.  If you use cheap service parts, you are also asking for trouble.

Engine Oil

I use only synthetic oil in everything I own including my lawn mower.  Once you understand just how superior synthetic oil is, you will never go back.  I saw the difference first hand in a 1982 Honda XR250 motorcycle.  This is an air cooled 4-stroke bike.  At the time I lived in Southeast Washington State where there were many sand dunes.  Soft sand really works a bikes engine hard. They get very hot.  I was using original equipment Honda oil in it.  After just 3 rides in the dunes, the oil would be noticeably thicker and very black.  I switched to synthetic (Mobil One) and I could now go 30 rides and it still looked good.  Huge difference.  After I saw that, I was convinced.  I also worked on many turbocharged engines when I was a mechanic.  I saw too many turbo failures caused by oil coking in the bearing.  Basically natural oil cannot handle heat.  Engines make heat.  So, rule #1: use only synthetic oils in all engines.

On cars that get driven at least 10k a year, and that 10k does not have excessive cold starts and very short trips in it, you can go 10k to 15k miles between oil changes if you use good synthetic oil.  I use Mobil One extended performance in most my cars.  My daily driver does get many short trips and cold operation so it gets changed much more often.  Long trips are much easier on the oil so if I take a road trip I may go more miles between changes.  I also like to monitor the oil condition.  I look for excessive blackness, moisture, and viscosity changes,

Spark Plugs (for gasoline engines)

Back in the day spark plugs only lasted about 10k miles.  Cars built since about 1995 can go up to 100k miles on a set of spark plugs, although they are much more expensive spark plugs made with precious metals like platinum or iridium.  The spark plug type and engine dynamics vary the recommended change interval so check with the maintenance schedule for your particular car to find the recommended change interval.  My cars all require spark plugs every 60k miles.  I prefer to use the cars original spark plug.  Often you can get the supplier branded plug which is equivalent.  For instance, many Mercedes use Bosch spark plugs so you can buy the Bosch branded plugs versus buying them directly from Mercedes.  If you let the plugs go too long, the firing voltage increases to where the energy will find new creative paths to ground.  This means failed secondary ignition components which for most modern cars is now the coils.  Best to maintain your spark plugs to prevent that.  

Transmission Oil

Modern cars with automatic transmissions are starting to go to longer term maintenance intervals, some claiming the life of the car.   My XJR had such a transmission.  However, at 120k miles it started doing some strange things.  It would lock up the converter and stall the engine when coming to a stop.  It happened randomly and not all that often but it was really annoying when it happened.  Sometimes it would take several attempts to get going again.  I drained the fluid to change the filter and found the fluid was very cloudy and brown.  It made a fine mud in the pan too.  Suspecting a failing converter clutch I replace the transmission torque converter, the fluid, and filter.  Just as I got the car going again it locked up.  This time I removed the valve body and disassembled it.  I found that mud all over in the valve body clogging passages and orifices and gumming everything up.  I cleaned everything thoroughly and the problem was solved.  So, I now wonder if that lifetime fluid thing really works.  

Brakes

Brakes are an area of particular concern and cheap parts should never be used here.  I had an F250 truck I once installed a set on $19 front brake pads in.  The thing was dangerous after that.  It just could not stop.  I think stopping distance must have increased by at least 30%.  It was awful.  I replaced them a few months later with a good set of Hawk premium pads (about $80) and told myself never again will I use cheap pads.  Another thing cheap pads do is dirty your wheels and squeal.  Not at all worth it.  I prefer Hawk but there are other good brands as well.

Fuel

Even the gas you use makes a difference.  Never try and be cheap by putting in a lower octane than the manufacturer requires.  Always go equal or higher on octane rating.  Also, don't use cheap gas, ever.  Get it from a Shell, Exxon, Mobil, BP, Chevron, etc.  I once got "premium" gas at a Hucks station and put it in my Crown Vic (which only required regular).  The car rattled bad with detonation.  Definitely NOT premium in any way.  Another time I put premium from a no-name station in my XJ8L (which requires premium).  I was on a trip and as I was driving down the highway I noticed a lack of power, surging, and very bad fuel economy (like 10mpg off).  I suspect they had made "premium" by dumping a whole bunch of alcohol in it.  While this does increase the octane rating to prevent detonation, it also has less energy and requires a different air fuel ratio.  I went ahead and continued driving until my tank was down and filled up at a Shell.  Problem solved.  Another problem you can have with cheap gas is poor maintenance of the tanks and pumps at the station which can leave dirt and other material in the fuel.  This plugs your fuel filter and can damage pumps.  The detergents in the fuel are required to keep your fuel system clean.  Back in the late 1980's we had to clean injectors on dozens of cars every week at the shop before fuels started getting the detergents they needed and injector designs improved.   Cheap gas may lack these important detergents.

These detergents not only clean the fuel system but they also help reduce carbon in the engine.  Engine carbon buildup can cause all sorts or problems.  Here is one example of a van with a bad knock that was just carbon.  We fixed this with a few bottles of water.
Don't try this unless you know what you are doing.  Be careful not to get too much water into the engine too fast.  Major engine damage can occur if done incorrectly.  With that said, I have done this to many engines before and never had a problem. You start by getting the carbon hot.  Hold the engine speed up around 3000rpm or so for several minutes.  This will make a terrible noise but there is no good way around it.  Now, find a small vacuum line that goes to a place in the intake manifold that will effect all cylinders.  A hose close to the throttle works.  While holding the engine speed above 3000 put the hose into a full water bottle and let the vacuum suck the water into the engine.  You will need to apply more throttle as the water will make the engine speed drop.  Often you will need to hit 3/4 throttle or so.  After all the water is in the engine you can let it idle again.  If the noise is still present, repeat.  The van above took 3 bottles (16oz to 20oz each) to clear up the knock.

Belts

Most modern cars use Poly-V bents that follow a long path and wrap around pulleys in different directions.  They are commonly referred to as serpentine belts because of this.  These belts are much better than the old V-belts back in the day.  They typically last 60k miles or more.  However, if you run them to failure bad things can happen.  They can get tangles up in adjacent components like hoses, wire harnesses, and other parts and rip them all apart.  Even if that does not happen you are generally stuck on the side of the road since you will often loose charging, cooling, power steering, etc.  Best to keep them in good shape.  Changing them is usually easy and most cars have a routing map under the hood in case you forget how they go on.  These belts can actually accept a certain level of cracking on the ribs and still be OK.  It is easiest to see the cracking where the belt wraps backwards over the pulley (the ribs on the outside).  If any chinks are missing replace the belt right away.  If the cracking gets too excessive change the belt.  

Cam drive belts (timing belts) are a special case.  These must be replaced at the factory specified interval.  It is best to get a complete kit when replacing them.  these kits often include all idlers, a water pump, and tensioners depending on the application.  When these belts fail, severe engine damage generally occurs.  Some engines are designed so that timing belt failure will not damage the engine.  these engines are often called free-wheeling but they are the exception not the rule.  Luckily most modern cars have gone back to chain drives but back in the 1980's and 1990's many cars had timing belts.  Changing timing belts can involve special tools and often involves at least a half day of labor or more.  

Hoses

Cooling system failures are one of the most common causes of cars ending up on the side of the road.  There are many cooling hoses on most modern cars.  If you keep your coolant in good condition these hoses can often last 15 years.  However, you need to check them periodically.  If they get harder or softer replace them right away.  After about 15 years you need to really get them replaced.  In some cases you may need to replace them earlier than that.  

Suspension

Some roads, like the terrible roads here in the Midwest, can really abuse your cars suspension causing premature wear and failure of wheel bearings and suspension components.  This can be dangerous!  Inspect your suspension at least yearly.  Rock the steering wheel back of forth and feel for any clunks or looseness. Raise the wheels off the ground with a floor jack and try to move the top and bottom of the wheel in and out firmly.  Modern cars with sealed wheel bearings should have no looseness.  Visually inspect all suspension bushings too.  

Service Information and Tools

Model year 1996 or newer vehicles sold in the US fall under a law called Service Information Rule (SIR) which dictates that OEM service information and electronic service tool must be made available outside the OEM dealer network for "a reasonable fee" which the government "helps" the OEM decide.  Because of this, you can access the factory manuals to service your vehicle.  It is required that it be a website where users can subscribe for various access levels.  The National Automotive Service Task Force (NASTF) polices this to make sure OEM are complying.  You can find their website here: http://nastf.org/ .  You can sign up for a free account.  They keep a directory of where to find these OEM service information websites since they are rarely linked from the OEM's main public website.  Right-to-Repair laws are expanding this beyond emissions related system to include the whole vehicle.    



More to come....
I plan to add more to this so check back occasionally.