oil in coolant

[jakuza1979]

Well, I'm pretty sure I have a blown head gasket, but I like to get advice. I noticed oil in my overflow reservoir, and in my radiator, but no antifreeze in the motor. the coolant level slowly depleats after topping off, but no leaks. when the level goes low, it does start to run hot, but otherwise runs normally. Also, when I top the antifreeze level, it starts up a little rough, but smooths out once it warms up. The exhaust smell when it is running rough at cold start up smells slightly sweet. So am I right about the head gasket, or is it possibly something else? I've read about a few posts that indicate the possibility of the oil cooler seal being the culprit. All advice and comments are greatly appreciated.

[Dave Colangelo]

Oil cooler is leaking...

If the car runs more or less ok then chances are its not a blown head gasket although I have never had it happen so dont take my word as a rule. I have read alot about the cooler leaking so I would bet that is what it is. Could be a good excuse to do new belts, water pump, oil cooler etc.

Regards
Dave

[Brozoar]

Condolences.

It most likely is the oil cooler. There are, according to most, very few ways that oil could hit the coolant if it were the HG, and the oil cooler is a pretty well-acknowledged Achilles' heel of the 944.

There's a fair bit of tear-down to get to it, but replacing the seals once you have everything out of the way is pretty easy. Of course, if (as in my case) your power-steering pump bushings have WELDED themselves to the aluminum bracket so that you can't get it out, it's a whole different story. I spent two whole days trying to get that out, eventually gave up and ended up having to drain the PS, disconnect the hoses, and weasel the oil cooler element out of the housing and past the pump THROUGH the exhaust headers. It was the worst couple of days of my life...

[Brozoar]

Oh, also watch out; there are several slight variations of the oil pressure release valve in existence (4 in total, I think). The seals you need vary depending on which OPRV you've got, and it's not always easy to tell.

[djnolan]

With some skill and good tools, you can remove the oil cooler housing from above without removing the exhaust header or any other major parts. It is a few dollars for the parts. Start with a good craftsman 1/4" drive socket set with a universal and a flexi extension.

[HondaDustR]

Originally Posted by djnolan

With some skill and good tools, you can remove the oil cooler housing from above without removing the exhaust header or any other major parts. It is a few dollars for the parts. Start with a good craftsman 1/4" drive socket set with a universal and a flexi extension.

Now that's a rare skill I forsee never achieving. Did it once with the headers in place and that's the last time I'll do that to myself.

[mytrplseven]

I'd check the oil dipstick and see if it shows or smells like anti-freeze. Just to be sure, after all the other work is done, I'd drain the oil and look at it closely for anti-freeze contamination. If you see it and you've run the engine for some time, I'd be concerned about galling of the main and rod bearing surfaces. Hopefully that won't be the case.

[djnolan]

Originally Posted by HondaDustR

Now that's a rare skill I forsee never achieving. Did it once with the headers in place and that's the last time I'll do that to myself.

For me it was the lesser of two evils. Removing ancient exhaust header flange bolts was a no go without a lift.

[HondaDustR]

You have a point. At the time I decided to give it a shot without removing the headers. Some time later I spent an entire weekend replacing a leaking exhaust gasket. Stainless bolts and copper nuts have kept it a 20 min job after that.

[djnolan]

It turns out I cracked my original tube headers trying to remove them to repair oil cooler seals. It was partly because I tried to pry on them like an idiot. Later I had to have a shop replace the headers with a cast iron set. I wouldn't even attempt to remove headers w/o a lift.