elbeee964

Nope.
(A half hour after I've parked in the garage, the difference between the two fender temps is still obvious.)

Crapped-out Thermostat just went to the head of my usual suspect list for this case.
(With his closest known associate, Crimped Tubing, a distinct, though less likely, slippery-alibied suspect.)

Duck

Even if the fans are not working, you should see a drop in temp as soon as the thermostat opens. It is a noticeable drop and then the temp should start building again. If you only saw a steady climb in temp and no drop, then I would really consider checking the thermostat again.

DWS964

+1

If that temp drop is observed, then the next likely candidate is the resistor that controls the low speed fan.
Do you have access to a Scantool (or Hammer)? There is a test sequence for the climate control unit (yes, it controls the oil cooler fan) that will test both low and high speed operation of the fan. If low speed does not come on, then the resistor is bad. Failure of the AC fan resistor is much more common, however, due to its proximity to the battery vent and the resultant corrosive environment.

And, not to start a new battle... But I notice a definitely higher oil temperature when I have my undertray installed. This is a good thing in the winter, and is why I install it for winter driving. Without it, I found that my oil temperature many times did not get to the point at which the thermostat opened. Now in the winter my oil temperature climbs and the thermostat cycles properly. As a result, my oil is staying cleaner and my gas mileage is noticeably improved.
Is your undertray still installed? Probably not a good idea for hot climates.
OK, end of story - no debates over the undertray, guys.

good luck.
have fun, be safe

911Jetta

Duck,
That's exactly what I'm thinking also...a bad thermostat may still be lurking in there?

So hoping that I wasn't going down the wrong road, I installed the new oil cooler ballast resistor last night. I don't see how anyone can replace the resistor just by taking the wheel arch liner out? It's at the top, far side (very front nose of the fender) of the oil cooler - a very tight, narrow space about 18 inches in. I finally got an Allen wrench on it, but there was no way it was going to come out this way?

I decided to go even deeper with this project and take off the front bumper (another HUGE first from me ). Now I had better access (mostly from below)...the resistor was toast! Now my low-speed fan works, at least it was worth replacing and my time wasn't totally wasted?!

I finished so late last night I didn't want to wake the neighbors and go for a test drive...will test it this afternoon. Still worried about the thermostat (and will ask more questions about the parts listing later (thermo+spring+cap+o-ring+c-clip+more oil+new sil clips).

It took hours of work to get to this point, and maybe many more to come (I know I need to replace the weeping line coming into/out of the cooler), but I know so much more about this part of the car now...wow, that's the consolation prize at this point.

Here are a couple pictures, best part was when I son helped with the bumper:

elbeee964

(I think I know how this movie goes - but it never gets boring. Like watching The Dirty Dozen on Sat. afternoon TV.)

jimq

I did mine by just taking off the wheel liner and the cover with the exhaust vents for the hot air underneath.

911Jetta

Very good point.

I'm sure the resistor could be changed just by removing the liner and bottom cover, but it was still too tight for my fat fingers, and the area was full of grit that needed to be cleaned out before installing the resistor...

I was under the impression that I would gain much better access if I took the bumper off (mostly from the side, not below).

axl911

Oil lines doesn't look that bad. I hate messing with oil line and its connectors. Difficult to get right and not making the leak worse.

jimq

there are a couple of foam like baffels that fit around the fan and cooler. These supposedly direct the air into the cooler. I dont know what effect then being gone would have.

Duck

The baffles in my car crumbled into dust about a year ago. Not sure if it affected the cooling.

911Jetta

That's the least of my worries right now.

Came back from a drive...cool fender.
I thought my fender felt a little too cool after my drive the other day...darn slippery-alibied suspect (Lonnie)

I've come so far, and would hate to give up now but I'm worried I find weeping oil lines or other things that will make me happy a shop has it. I'm recovering from yesterday's work so energy is low...

Maybe I'll order the parts, start the project and call AAA if I see anything ugly after taking the sils off. Getting energy back!

So looking at dfinnegan's recent thread I will look to confirm the following parts are correct:

964.207.047.08 thermostat
93 version supercedes all others
order from germany 4-6 wks
includes
circlip
o-ring
washer
circlip
screw plug
compression spring
13mm ball

Plus sil clips, 6+ quarts of oil.

911Jetta

Just ordered:
964-207-349-02
Oil Thermostat Insert for External Thermostat Assembly
964 C2/C4/Turbo (1989-1994)

Plus cap (just in case?) and o-ring.

GSBelo

Hey - my first post...

Might be a bit late - but my understanding is that part 964.207.047.08 (thermostat) - also includes 964.207.349.02 (valve/thermostate insert).

In the PET - the thermostat part no (#11 - I believe) 'brackets' in a few other parts - including the insert.

I have also just ordered 964.207.047.08 - and I was hoping/justifing the high cost was due to all the internals included.

Am I mistaken? Do I also need to order 964.207.349.02?

Robb B

Rocket Rob

I would replace the two rubber oil hoses attached to the thermostat. About 2 years ago, one of my hoses began to weep oil through the pores of the rubber. I replaced both. If you are going through the labor of removing the thermostat, I would replace the rubber hoses too. No increase in labor. My 2 cents.

Sultan

Not trying to hijack your thread.....if time permits at somepoint, do you mind providing step by step snaphots of how you got the front bumper off? My project this summer is to do a bumperette delete and I'm struggling with finding detailed pics on how to do it.

There are some threads on bumperette deletes and bumper removal but not a real step by step picture guide - I need front bumper removal for Dummies. No hurry, solve your overheating issue first! Much appreciated in advance.