Oil cooler sprung a leak?

[dfhtrhjn]

Here's a pic of it actively dripping, and the top where the breather is. You can see a drop about to fall on the pipe, and one about to drip from the pipe onto the heat exchanger. The leak doesn't see to be coming from the breather or that thermostat(?) next to it.

I replaced the S-hose last night because it was older than I am and that's when I noticed the drip.

Since the inlets to the oil cooler are on the back side, I'm worried the drip is from the cooler and not the gaskets that mate it to the case.






Any thoughts?

Also how easy is it to check the cooler once I remove it? They aren't cheap and I hoping to avoid buying one if not necessary.

Thanks

[boyt911sc]

Steve,

You can remove the engine cooler with the engine installed in the car. After removing the cooler from the engine, you simply do a pressure test. Pressurized the oil cooler with air and submerge it in water. If it has a leak, it will show up during the test. If you need pictures of the gadgets, I could post them.

Tony

[dfhtrhjn]

Yea I can see the bottom two bolts, and I can see what sheet metal to remove to get to the top two bolts.

What plugs/fittings do you use to pressure test? I'm going to drain the oil and pull the cooler tonight.

[DRACO A5OG]

I don't know, looks like breather hose is leaking at the fitment or it may be the gasket.

If I may suggest, clean the Triangle area well and then come back and observe where the oil is coming from and then swap the gasket and or the hose. Note the hose when sitting on the breather neck, the neck has a divet that sometimes PO may have placed the clamp on and as a result will leak. So take care if you replace the hose to insure the clamp is in the correct position.

[dfhtrhjn]

The gaskets are already in the mail I ordered the breather and oil cooler gaskets. The breather was sweating oil at the gasket on the opposite side of the cooler, but dry on the oil cooler side. I cleaned the cooler too, but it started dripping right away when I ran the engine.

I suppose I'll know more once I pull some of the sheet metal covering the cooler, but the cooler is getting fresh gaskets no matter what.

I've had the car on the lift for a week as I poke around in there to find the problem. Any other suggestions while I've got it up in the air?

[uwanna]

Your triangle area looks pretty clean to me. I had a similar problem some years ago.
I had been using Castrol 20w-50 for years and opted to switch to Brad Penn.
Shortly there after my oil cooler developed a leak that looks EXACTLY like yours.
I think over the years I must have had a pinhole leak in the cooler but debris in the
oil had plugged it. Apparently the new Brad Penn and detergent additives cleaned out the plugged pinhole and the cooler started dribbling oil onto the heat exchangers!
I replaced the cooler with a known good one, problem fixed. I hate to be the bearer of bad news, but looks like a leaker to me. Good luck with a fix.
Best,
Grant

[boyt911sc]

Originally Posted by dfhtrhjn

Yea I can see the bottom two bolts, and I can see what sheet metal to remove to get to the top two bolts.

What plugs/fittings do you use to pressure test? I'm going to drain the oil and pull the cooler tonight.

Steve,

Attached are some pictures of the gadgets I've been using for the pressure tests. I have two sets of tools for this particular job:
a). A home-made gizmo that works well too for my needs.
b). The fancy tool from Stomski.







Try to find out someone local that has a similar tool that you could borrow before making or buying one for yourself. Keep us posted.

Tony

[dfhtrhjn]

Oh that Stomski sure is neat.

Grant, that's what happened to me too. That area looked like it was sweating oil very slowly until I changed my oil this last time, about two weeks ago. Since then it's been dripping at a pretty good pace. Up till now there wasn't enough oil to tell where it was coming from.

[theiceman]

I love the home made tool , its awesome !!!

[fanaudical]

That sure looks like an oil cooler leak/drip to me.

Pacific Oil Cooler Service can sometimes repair those (provided they can get access to the leak).

[dfhtrhjn]

I pulled the cooler last night, takes about 45 min. I ended up pulling it up and out through the top of the motor so I wouldn't have to remove the oil lines going to my external thermostat.


There was no other oil in the surrounding areas of the engine which is a relief.




It is a little messier pulling it out the top, but it slides straight up. Obviously not possible if you have stock engine management...




The top of the cooler was bone dry, but the bottom was a hot mess.




I found a pressure tested cooler on ebay for $360 that I ordered which sure beats the $1700 price tag of a new one.

On a related note, I can definitely see why the engine oil cooler eventually went away with the 3.6 liter engines.

Thanks for all the advice and help everyone!

[uwanna]

Originally Posted by dfhtrhjn

On a related note, I can definitely see why the engine oil cooler eventually went away with the 3.6 liter engines.

The ONLY reason the cooler went away on the 964 3.6 was to make space for the power steering pump! I retrofitted an on engine cooler to my 964 3.6 when I did the install
to my '80SC. By having the engine cooler and a Carrera fender cooler I didn't need
any additional coolers upfront like most folks need to do when they transplant to an earlier chassis.

When the 993 and 3.6Turbo came out they added a pressurized oil filter in place of the cooler but it didn't interfere
with the cam driven power steering pump. That filter was added because of the new hydraulic rocker assemblies which are very sensative to any contaminants in the oil.

[dfhtrhjn]

Oh I see. Meanwhile I was thinking it would be nice to get rid of the engine cooler altogether since my front center cooler is a beast. I'm not sure how I would have replaced this cooler on my other 911 with stock CIS in the way.