Oil in Coolant

[Hanz Mannly]

So I pull into my garage, pop the hood to check the oil and other fluids. I look down at my radiator cap and notice a choco color oozing out of it. Smells like oil and coolant mixed. At this point, I'm worried its the head gasket.

There wasn't any water in the oil, and it didn't smoke that I noticed. There wasn't any power loss that I could tell.

I bought the '99 Cobra at the end of November '06. Before I signed on the dotted line, I took it in and had it checked out. The test came back good. Only thing that worried the mechanic was a slight oil leak around the head on the driver's side in the back. But the compression test came back almost even across the board. I haven't had it tested for compression since this happened.

I have drained the coolant and the oil. Pulled off the oil cooler to clean it and inspect it. Could an oil cooler do this much damage? or am I hosed and have to change the head gasket ?

I tried to scan the forums about this problem so I didn't have to repeat a thread that could have helped me already. But, I wasn't able to find what I needed. Any advice or input anyone might have to help me fix this issue would help greatly.

Thanks. :SNSign:

 

[Uncle Meat]

Welcome to the boards.

First thing I'd do is perform another compression test.

U.M.

 

[COBRA90GT]

Try pressure testing the cooling system if you haven't already done so. Blowing the headgasket on these engines is kind of rare, but it does happen...

Did you replace the gasket/o-rings on the oil cooler too while you had it apart?

 

[Hanz Mannly]

I just got home from work and the auto parts store. I picked up a compression tester and plan on getting that done tonight. If I have even numbers on all cylinders (or close to even), can I rule out the head gasket ? or will there still be a possibility of a blown gasket ?

When I found out about this problem, I had knew I had to get stuff from the parts store. In my haste and confusion to fix said problem I forgot to purchase an oil filter. All O-rings and filter will be replaced tomorrow and Friday (my days off).

When I bought the Cobra, I also bought a Haynes repair manual. I have heard that there was a better repair guide to go by instead of Haynes. If so, what is it? Or, will the Haynes manual suffice? I have always hated going to the repair shops to get work done, you can hardly trust them.

Thanks for the help guys. I will post results when I get them.

 

[Hanz Mannly]

Ok .. so I'm done with the compression test. Frankly, I'm baffled.


Cyl 1 150 Psi.
Cyl 2 145
Cyl 3 160
Cyl 4 145
Cyl 5 145
Cyl 6 152
Cyl 7 155
Cyl 8 165

I'm going to take it in and have a pressure test done on the coolant system tomorrow.

Oil cooler and gaskets looked good. However, while I had the adapter to the oil cooler off I didn't notice any corrosion in the area. But I could be wrong. I will recheck when I change the oil again in the next day or so.

 

[Hanz Mannly]

Well, turns out it was the oil cooler that went bad. When I first bought the car I had that part replaced by the dealer. The part was under warranty and replaced for free, as was the system flush they preformed.

I just wanted to close this thread to help out anyone else that might have this problem in the future.

 

[stangme]

Oil cooler failure 96 cobra

Well, turns out it was the oil cooler that went bad. When I first bought the car I had that part replaced by the dealer. The part was under warranty and replaced for free, as was the system flush they preformed.

I just wanted to close this thread to help out anyone else that might have this problem in the future.

long rant..... im lucky...
Just had this same problem... low oil light on, oil pressure shows as usual, water temps normal... pull into wal-mart to check it... none on the stick... glad i run mobil 1, no leaks visible anywhere, no smoke out the exhaust.... put the mobil 1 oil back in.. drive her home 30 miles... check the oil before leaving for work.. next morning...looks good, drive 30 miles to work, check the oil.. no problems, then drive another 140 miles round trip for a meeting.... mostly at 80mph.. no low oil light... oil pressure good, water temps good..... get up the next morning... check oil.. bone dry... notice dark water etc around radiator cap... its oil and coolant...
oil cooler adapter failed.. pumped all the oil out of my motor into the radiator... 290.00 for the adapter.. and still waiting for the shop to finish flushing system... merry Xmas.. looks like i get a new oil cooler and system flush from santa.. but hey... almost 250k miles on my daily driver.. and she hasnt had any real problems... so i cant complain tooo much...

 

[cobradude]

Glad to hear you caught the problem before you ended up with major engine problems. Merry Christmas!

 

[cobranator]

... almost 250k miles on my daily driver.. and she hasnt had any real problems... so i cant complain tooo much...

Wow that's a lot of miles and people think that only Honda and Toyota can build good engines.Ha!!!!!!! . It just proves that the DOHC Cobra motor is really a stout piece and will last a long time. A lot of people on these boards have been asking about how well these engines do in the long term and you can certainly answer that question unequivocaly as you have first hand experience. If there's still any doubts about the engine you're experience puts them all to rest.