04 2.7T, 6spd manual.

My style is "fix it before it breaks," but not being familiar with the car and having 160k on the odometer means I've had several instances where it doesn't start on account of a <100$ sensor, or in this case, voids the coolant circuit through some currently-undiagnosed leak.

Every instance could've been prevented if I'd known what to look at.

Last owner:
Clutch
Aux coolant pump

So far on my watch, 98k to present 160k:
CTS (green sensor)
Fan switch (blue sensor)
TB/WP (done w/ blauparts kit at 120k by a good shop)
Cam cover seals
Brake light switch
Main speed sensor (on the transmission)
Oiled SAIP motor
Repaired cracked SAI tube
Headlight leveling sensor

And now some part of the cooling circuit, not sure yet.

I've wrenched everything except the TB/WP. Not afraid to turn a wrench. TB/WP and fan switch were maintenance, not broken parts, thankfully.

I really like this car. I don't feel any need to modify it, it does what I ask of it, it's comfortable to drive, and I definitely feel like it would be perfectly reliable as long as I know what to replace and when. IMHO, every one of those sensors (except possibly headlight leveling) should be a 90k item, and the cam cover seals should be part of TB/WP service. If I'd had any idea, I'd have swapped that roughly 200$ worth of sensors when I bought it, and avoided half a dozen hot-restart failures and several rounds of diagnosis. None of that stuff is in the maintenance charts, so I'm turning to you all for advice .

Looks like the car will be in my garage for a bit, and I have a second vehicle to drive. I want to address all the other nonsense that might make it unreliable.

Any suggestions anyone might have, I am willing to listen. I want to take care of as much as possible during this round, including the intermittently rattling metal bracket in the sunroof...

Hoses? Starter? Seals? Radiator? Which sensors?

Thanks in advance, everyone. I'd like to enjoy this car another 40k miles at least.

-Sean

 

At 160k I'd be thinking about the fuel pump, alternator and starter because any one of these parts can really leave you stranded, radiator wear failures are more based on the elements of the environment like salt or calcium chloride but generally if you see weeping at the the seams it's time.

 

Good call on the fuel pump!

Any sensors you can think of, in the "car won't start" or "car won't run" categories?

This catastrophic coolant leak better not be the Blauparts water pump I keep reading about...but I will post either way as soon as I know.

 

Only preventive maintenance I'd consider is replace the alternator brush/regulator assembly at 140K miles.
Fuel pumps and starters last until they go, several hundred thousand miles unless they break.
Change fuel filter, use top tier gas, don't run the tank dry, use an ethanol stabilizer like stabile 360 or cleaner additive like techron once in awhile.
Change transmission oil and filer every 50K automatic transmission.
Diff and rear end lube, at 50k fist time, if it's dirty do it again at 100 otherwise go to 75k. And if still clean go to 100.
I've run synthetic dif lube to 100k and it looked like new.

 

Bumping my own thread for this. Thanks for the help on my other questions!

I'll have the front of the block stripped down this evening except for the TB relay lever (not going to bother removing/replacing, no bearings), and I'm going to pull the intake manifold and look over the auxiliary coolant pump as well, since I can see some leakage around the hoses there.

Parts list for TB/WP service so far, am I missing anything? All factory parts.
TB
WP (new, includes gasket)
Hydraulic tensioner
TB tensioner pulley
TB idler pulley
T-stat
T-stat gasket
Serpentine belt tensioner pulley--can I replace this w/o replacing the tensioner assy?
Lower radiator hose
Coolant line from coolant manifold/t-stat cover to the metal pipe leading to the oil filter block, I don't know the proper name for it but it's a simple hose, spring clamps on each end, apparently the part number is 078121096AC.

Other parts...
Fuel pump
Starter (new)
Voltage regulator (for alternator)

Maybe?
Aux coolant pump + assorted hoses, clamps

Anything else? I realize this is far more expensive than buying a "kit" from somewhere, but one of those kits resulted in my doing this 40k after the last TB service, because the water pump and TB tensioner pulley failed. The cam seals look good, and there's no oil leaking from the front main seal either, and the cam cover seals are "good enough", I did them a while back and I'll leave them til I hit 225k and the next TB service.

How about the sensor shoehorned between the driver's side head and the rear timing belt cover? Is that easy to replace with the timing belt cover in place, or is it worth replacing now?

No sensors are *currently* causing any trouble, but I'd rather save myself a few roadside phone calls down the road and replace things now.

You guys figure I need to replace the hydraulic tensioner or serpentine belt tensioner+pulley? Both were included with the Blauparts kit, 40k miles ago. Have those parts proven trustworthy?

 

the only thing i can think of sensor wise is the coolant temp sensors if you dont already have the green ones installed you could do those. Those wont prevent the car from running but its never good to not know how hot your car is.

Another thing you might want to do is transmission and rear diff fluid. I believe you use 75/90w gear oil. I use Royal Purple and it made a nice difference with my trans.

There is nothing that goes around 160K (as far as sensors) that will prevent the car from starting. Not that i can think of.