timing chains and oil coolers

RSW · 09-18-2002, 04:14 AM

Hello Everyone - I've viewed this board for the past few days and it seem very informative and helpful.
I'm quite new to the Porsche ownership world and be grateful of a little advice from anyone who has come across the problms I'm about to describe. Any help is greatly recieved.

1988 - 911 Carrera 3.2 (UK Car)
I have at the moment got the engine out of the car as I wanted to have a good look over it. The problems are I am sure the engine oil cooler is leaking - it used to drip and I'm fairly sure it's not just the seals.
However a new one is £550 + vat - does anyone know where I can get a good second hand one ? I've tried loads of porsche spares places and you seem to take a chance that it's a decent cooler your buying. Is there a replica part on the market that could do the job? Or can these items be repaired anywhere?

My second problem was when I took the timing chain covers off I noticed that the tensioner cogs on the right had side chain had been catching the alloy webbing of the case dur to (i presume) the chain having too much slack in it, the left hand side one seems too loose also (it also sounded noisy when the engine was running) How do I fit a new chains? I can't seem to get behind the casing of the bottom fanbelt pull so see the other slippers etc.. Can anyone tell me the secret?

The third issue is tappet settings - I've bought the swan neck 0.10mm feeler gauge and fiddley though it is I can adjust the tappets but how tight should a feeler gauge be? I can still force the tappet to make a fair old tap when I wobble them by hand after the adjustment ? Is this right?

Any advice is welcomed.
Many Thanks in advance to anyone who can help.

Richard

RoninLB · 09-18-2002, 04:34 AM

...the engine oil cooler can be tested..I believe it's 100psi in a hot bath..but IMPO, if you have 100,000 miles on it?? .it's a problem waiting to happen..making that decision was a hard/expensive one for me......Ron

RSW · 09-18-2002, 04:41 AM

Thanks Ron - It's actually away getting tested at the moment but I'm expecting the worst - the car has done 113k miles but I'm not sure how long they traditionally last.
PS what does "IMPO" stand for - forgive my ignorance.

makaio · 09-18-2002, 04:47 AM

IMPO = In my opinion.

As far as used engine oil coolers, I wouldn't take the gamble using one. How the engine they came from lived can be very bad.

AS far as timimg chains go, you can replace yours with a master link style. You have to cut yours, then connect the new ones to the old ones, and run them through. You will then have to time the cam shafts.

On valve lash, it should be a medium magnetic resistance. Not light, not heavy, but medium feel. That's the best way I know how to describe.

RoninLB · 09-18-2002, 04:54 AM

I don't have hard info on how long an engine oil cooler lasts..but a few pros humbly told me that it's a good idea if you plan on keeping the car..and I was doing a full rebuild and planning on keeping it..that was 40k mi. ago..do ask others around here because I'm into bullet proof........Ron

RSW · 09-18-2002, 04:59 AM

Thanks for the feedback - I guess my chains have stretched to cause this problem. As for the oil cooler it sounds like it would be a false echonomy not to fit new.

Regards
Richard

Chuck Moreland · 09-18-2002, 06:48 AM

For the valve adjustment feel - Get a caliper or micrometer and set it to .1 mm. Try the gauge in the caliper to learn how it should feel. As Matt says it should feel like you are dragging the gauge over a magnet.

As for the cooler, those seals can leak a good bit - that may be your problem. I did have one develop a leak on me in the tubing once. It just peed out the oil! It was obviously the tubes since it was coming out of the middle of the cooler, not dripping down the side like it will with bad seals.

You can get a used one but be careful. If the engine it came off of blew up, it may have metal particles in it. Dont get a used one unless you know and trust the source.

RSW · 09-18-2002, 07:12 AM

A Micrometer sound a good idea - I will invest in one of those. I've been put off buying a second hand oil cooler, I am however getting mine tested at the moment to ensure it is leaking.

0.10mm is a very small amount - you'd think the metal would heat up and expand causing the valve not to shut wouldn't you?

Thanks

Chuck Moreland · 09-18-2002, 07:25 AM

Yes, but the head expands too which has the effect of increasing valve clearance. And the head is aluminum or mag and has a higher coefficient of expansion than the valve train.

Early_S_Man · 09-18-2002, 07:25 AM

Richard,

There are three seals on that cooler ... two smaller ones at the top handle the pressurized oil from the main oil pump to the main oil galleries, and the lower, larger one that is the supply line to the pressure pump from the dry sump tank. Any seal leaks there should have been obvious when the cooler was removed.

If the leak was from the large lower supply line tube, that can be repaired fairly easily by TIG welding. Some leaks in the cooler tubes can be repaired by TIG welding, others not, but much trickier repair job!

RSW · 09-18-2002, 07:50 AM

When I took the cooler off it had white mastic around the 3 seals which I suspect was not of Porsche origin. I suspect the cooler has been off before. However prior to removing the cooler I noticed the oil seemed to be coming from the fins along the bottom of the unit which suggested to me that an internal component of the cooler we leaking.
When I get the results of the preasure test back it will be more conclusive. The daft thing is the unit looks to be in good condition from the out side.

Thanks
Richard