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Re: Case of the missing coolant

Posted: Sun Jan 04, 2026 10:32 am
by Tom
Poorsche44 wrote: Sun Jan 04, 2026 10:12 am Ah I should’ve specified I have a 5 digit odometer. The only other thing I would want to do soon is the valve cover gasket as it leaks slightly, but I plan on doing that with my next timing belt job next year.
Ah, right, sorry, forgot this was an early 944... Changing the cam tower gasket gets you about 80% of the way to the HG. So if the oil seals don't fix the mixing, you can fix the cam tower and HG as part of the same job anyway.

Re: Case of the missing coolant

Posted: Sun Jan 04, 2026 1:18 pm
by BennSport
Sounds good, I’ll do that then! For my oil cooler alignment tool, I need the tool for the 3 piece cooler setup, right?

Re: Case of the missing coolant

Posted: Sun Jan 04, 2026 1:32 pm
by Tom
Poorsche44 wrote: Sun Jan 04, 2026 1:18 pm Sounds good, I’ll do that then! For my oil cooler alignment tool, I need the tool for the 3 piece cooler setup, right?
Right -- 3-piece pressure relief valve originally -- though it's possible yours has been upgraded to the one-piece retrofit part (still the same alignment tool though).

Re: Case of the missing coolant

Posted: Sun Jan 04, 2026 1:40 pm
by BennSport
Perfect, thank you so much! I saw someone made a 3d file for the 3 piece tool on here so I’ll print that sometime this week.

Re: Case of the missing coolant

Posted: Thu Jan 08, 2026 2:48 pm
by Damo
Poorsche44 wrote: Sun Jan 04, 2026 1:40 pm Perfect, thank you so much! I saw someone made a 3d file for the 3 piece tool on here so I’ll print that sometime this week.
That’s the one I posted after replacing the o-rings and gasket on my oil cooler recently. A few tips since it’s still fresh for me:

1. Removing the oil cooler and housing really needs the exhaust manifolds out of the way which are easy to remove out the top when the cam tower is removed (mine was already off). If you have a cam tower leak it might be best to do it all together.

2. Scrape/clean out any dry coolant from the housing so you don’t damage the o-ring. Mine was very crusty and rough and I thought I got it all but there was a small deposit that nicked the o-ring during the test fit. I had to track down a new single high temp o-ring to complete the job.

3. The 3 piece OPRV is challenging to reinstall due to the stiff spring and fine threads. I think I spent about 40 mins under the car to get the threads to start engaging cleanly.

Re: Case of the missing coolant

Posted: Thu Jan 08, 2026 3:42 pm
by BennSport
Thank you @Damo for the file and all that good info! Since I didn’t order a cam housing gasket yet and I have to get the job done this weekend it’ll be a little bit more challenging. Any tips you found for reinstalling the OPRV?

Re: Case of the missing coolant

Posted: Fri Jan 09, 2026 12:24 pm
by Damo
@Poorsche44 I had a socket on the end of the OPRV with a short extension and lay under the car which was on jack stands.

First I threaded the end in without the plunger and spring to see the correct angle,
then it was just muscle, sweating and swearing until it started to thread in :)

Re: Case of the missing coolant

Posted: Fri Jan 09, 2026 9:11 pm
by BennSport
So I removed the housing tonight and I saw this protruding part by the OPRV and I was wondering if this is normal. I have removed the threaded component, spring, and the plunger though.

Re: Case of the missing coolant

Posted: Sat Jan 10, 2026 1:11 pm
by BennSport
Also, I’m refitting the cooler element and if I have the plastic washer between the element and housing I’m noticing that the element is sitting significantly more proud than the housing itself. I was wondering if it’s okay for me to go ahead with the install excluding the plastic shim? If I test fit it without the plastic washer and including 1 of the metal shims the fitment is much better.

Re: Case of the missing coolant

Posted: Sat Jan 10, 2026 3:32 pm
by Tom
We are doing similar jobs at the same time, just n/a v turbo.

The sleeve is normal, and should not be loose.

Not all set-ups require the shim. Did you see this video. Hit settings and turn on captions in english...