Oil cooler stuck in housing

michaelcrisp · 11-24-2008, 02:27 AM

I have just removed the oil cooler housing and am finding it impossible to remove the oil cooler from inside the housing. Is there some trick to this?

John_AZ · 11-24-2008, 05:56 AM

Do not use a screwdriver to pry out the cooler! There is a large 1 inch "O" ring on each side of the cooler. The inner "O" ring has hardened. Rock the cooler as much as possible and gently lift with your fingers. Damage to the cooler fins will cause expensive repairs.
See www.Clarks-Garage.com for additional info.

GL
John_AZ
1988 924S + 1987 924S

michaelcrisp · 12-21-2008, 02:02 AM

Thank you for this - I managed to remove the oil cooler as suggested. I got the oil cooler pressure tested and ended up having to buy a new one anyway.

I now have a new cooler, gasket and some o-rings to put back together.

However, I have noticed since removing the cooler from the housing that the inside of the housing has a layer of white powder coating it - do you think this might be corrosion or some sort of precipitate from the coolant? I have removed some of this white powder but there is still a layer on about 1 half of the inside of the housing that is quite well stuck on there. I would presume that the rest of the cooling system is the same. Any suggestions?

John_AZ · 12-21-2008, 04:57 AM

Member Zero10 posted:
The white residue on the outside of the cylinders shows it was not filled with phosphate free anti-freeze at one time. That said, nearly all antifreeze now is phosphate free, even most of the green stuff.
I just use Prestone yellow, because it is available just about everywhere and its cheap (and phosphate free). Zero10
From:Need your advise with my 1988 944 n/a

What you are seeing is most likely the same.

You could flush your cooling system with a "mild" product. I do not recommend any HD-Heavy Duty flush. You are just interested in removing the "white deposit" from the block and radiator. If you use a HD product you may ruin the seal between the plastic to metal on the radiator.

If you see some of this white deposit on the heater control valve, replace it or it will drip on the clutch.

Do not forget to remove the block drain plug when you do the final flush.

GL
John_AZ

Schumi · 12-21-2008, 06:13 AM

Quote:

Originally Posted by michaelcrisp

I got the oil cooler pressure tested and ended up having to buy a new one anyway.

awwwww please tell me you got a used one and didn't get a new one at a dealer's price....

michaelcrisp · 12-21-2008, 11:46 AM

Ok - that doesn't sound so bad. I will flush the cooling and put it all back together and make sure I use phosphate free coolant.

I bought a brand new oil cooler and most likely got it at a dealer's price :-)

Zero10 · 12-21-2008, 12:52 PM

IIRC some CLR will do a wicked job of removing the buildup. It is just a coating of minerals and such from the water (or so I was told). When I had my engine apart the entire cooling system was gummed up with stop-leak, so I had bigger things to worry about, and by the time I got down to "just" having a white coating on things I was completely tired of cleaning stuff and just left it.

michaelcrisp · 01-07-2009, 03:56 PM

Ok - so I managed to clean the housing with CLR and it came up quite well. We spent about 10 hours yesterday installing the new cooler (it was rather awkward to work on but we managed it in the end). Along the way we removed the water tube that carries hot coolant for the heater and discovered the ends were quite rusted so haveblocked the rubber hoses that connect it for now and am going to purchase a new one. We also managed to snap off (an already rusty) tube attached to the exhaust pip while reconnecting the manifold. I presume this tube (which has a rubber cap at the top) is for analysing exhaust? Anyway - we also blanked this off to prevent exhaust escaping and I have no idea what to do about this one.

So thewhole process seemd to be a success - there is some oil weeping from the sender unit and a tiny bit seeping from the filter (although I may just be able to fix this with a new filter as we just reused the old on for now).

Baza · Baza's Garage

For future reference.
I refused to pay the price they wanted for a new cooler and could not bring myself to using a second hand unit. So I came up with the idea of replacing the cooler with a delete pipe. I made the delete pipe out of 1 inch stainless steel bar we had at work then turned it down so that it was the same size as the original cooler complete with cut out for the O rings, I then cut cooling fins into the center section, drilled out the the middle and there you have a delete pipe for the oil cooler. It took me about half an hour to make and looks a bit like a gun silencer but it works fine. All for the cost of about $150 if I had to pay for the bar and labour, and I dont think I will ever have that problem ever again( maybe the seals).

Schumi · 01-08-2009, 02:41 AM

Do you have an external oil cooler, like a sandwich plate style? Porsche put a cooler there for a reason. If you're driving around town it won't matter but if you push the car at all, without it you will see a rise in oil temps....

Baza · Baza's Garage

Schumi
At the moment I have not had any problems as I dont push it to hard for extended periods. But I do have a sandwich oil cooler sitting in the garage just in case.
I have a train of thought at the moment That the oil cooler is there to heat the oil in cold climates (snow) to aid the oil circulation and is not really needed in temperate climates were I am in winter it only gets to about 50 and in summer about 96
how ever I could be wrong thats why I have the cooler in the garage

michaelcrisp · 01-08-2009, 06:03 PM

That does sound like a neat way to fix the problem. I paid about AU$700 for the cooler and replaced it myself so I think I still saved money compared with taking it to a workshop. I would presume the oil cooler acts to keep the temperature of the oil down and I didn't want to risk the rest of the engine by not replacing it.

I have also now ordered a new water tube to replace the rusted one I removed to replace the cooler. I was originally going to get one made until I found that you could buy them for about US$40 new. So far so good with the car - I topped up the coolant after the first short drive and there doesn't seem to be any major oil or coolant leaks, the coolant in the overflow tank looks clean and the oil on the dipstick is also clean so it may have worked.