Oil in coolant

[blk\blk90]

I posted this on the FB page but didn't get a lot of responses, and I like asking the tech stuff here more. FB seems more for showing off.

I was poking around and found oil in both the overflow bottle and radiator. The exhaust doesn't smell sweet, and it doesn't smoke. Oil is still golden from being changed last march.

I don't drive the car much, maybe 1250 miles since I bought it in march. When I last swapped to a different x2j and pulled codes, the balance test said #6 was off.

When on the highway there is a definite misfire at random, but often. Once or twice a second. It also sounds off, and is definitely not putting out enough power, especially with the mods it has.

Heres a few pics:

 

[sperold]

There is a chance the former owner had his pre-teen son helping him and he dumped a small amount of oil or power steering fluid in the rad. before being stopped by dad.

Could be a total coincident that a miss showed up at this time.

Check #6 plug and wire.

Maybe someone will know what being "off" means on a balance test.

It would be expected that the coolant would have foam and bubbles if a dead cylinder was pumping cylinder contents past a bad head gasket.

Get a hand pressure pump that fits on the rad and see if you lose pressure after a pump-up.

 

[SM105K]

There is a chance the former owner had his pre-teen son helping him and he dumped a small amount of oil or power steering fluid in the rad. before being stopped by dad.

Could be a total coincident that a miss showed up at this time.

Check #6 plug and wire.

Maybe someone will know what being "off" means on a balance test.

It would be expected that the coolant would have foam and bubbles if a dead cylinder was pumping cylinder contents past a bad head gasket.

Get a hand pressure pump that fits on the rad and see if you lose pressure after a pump-up.

I would do a compression test as well.

 

[zoomlater]

Does it smell like oil? I thought you would see brown foam/milky as well. On one of my cars, I had this brown sludge build up in my radiator and reservoir as well. The car had a small leak from the radiator and my theory is the previous owner may have used some stop leak in it. I flushed the radiator and engine many, many, many, many,.... times until water came out no longer brown. Put in new coolant and I haven't had a sludge build up again. Do a compression test and see what shows up.

 

[blk\blk90]

I do have spark, and I can hear the injector firing on 6 with a stethoscope. I didn't smell it, but may let it sit and idle for a while and check it again. It doesn't look built up in the radiator, and I'm thinking the build up in the overflow is scale from coolant.

 

[luigisho]

Did you try a compression test to make sure a head gasket isn't leaking?

 

[blk\blk90]

I haven't yet. That's next on my list. Do all the plugs need to come out for that or just #6 and unplug the DIS?

 

[luigisho]

These show a few different methods. Are you sure there is no coolant in the oil? There are testers for cooling system pressure and also to confirm oil presence in coolant. Then there are pressure testing methods to verify heads and head gasket leaks. The other scenarios where oil can get into coolant is cracks in hard parts like heads and block. Look at some of these and go with the easiest and most likely scenarios you want to tackle first. Or you could crack open the wallet and have a pro knock it out for you.

 

[SHOdded]

Schrodinger's Box LOL

 

[SM105K]

That third video happened to my GTI. Oil cooler failed and oil got into the coolant. Took me a new oil cooler, and months of flushing.

 

[rubydist]

It is entirely possible that the head gasket is starting to fail and it is allowing oil into the coolant but not coolant into the oil. I would definitely look at the plug on #6 and see if it looks more fouled than the others.

 

[Irish Pride]

Which car is this? What's the history of this car? Have you done a proper coolant flush on this one since you've owned it?

My current white 89 needed a radiator soon after I bought it. I drained the system and put a new radiator in and filled it with fresh coolant but I never flushed the system. This past summer when the crank sensor went out I did a head and cam swap along with upper and front 60ks. I finally did a flush on the coolant system and this black slimy gunk started to come out. Ended up needing to be flushed 4 times over 2 weeks before I finally was able to get clear water coming out.

 

[blk\blk90]

This is the 91+ I went up to Indianapolis to get back in March; the one I've been making all the new posts about. I'm not sure on the history, and haven't done a flush. I know the PO did put in a double core radiator at some point, as well as a 3.2. That slimy black gunk sounds like what's in mine. Did you figure out what it was or where it came from? Can the oil cooler system leak into the coolant?

 

[PaulTAutoX]

This is the 91+ I went up to Indianapolis to get back in March; the one I've been making all the new posts about. I'm not sure on the history, and haven't done a flush. I know the PO did put in a double core radiator at some point, as well as a 3.2. That slimy black gunk sounds like what's in mine. Did you figure out what it was or where it came from? Can the oil cooler system leak into the coolant?

Haven't ever seen this on my SHO. I will say that when one of the head gaskets went on my Subie STI I was getting pressure from the intake back into the coolant system and it would move coolant into the catch reservoir, then when things cooled off it would draw it back into the coolant system! It would only noticeably on competition days when the boost had been on full. The garage had a hydrocarbons tester that confirmed that there was fuel in the coolant; not sure if those are sensitive to lubricating oil too. In the Gen I there is of course no pressurization of the intake (unless you have a s/c) but oil could be crossing the gasket into the coolant, as oil is minimum 30-40 psi and coolant is maximum well below that. Or a leak in an oil cooler if it is being cooled by coolant rather than air, likewise.

FWIW I did have an automotively ignorant friend put oil, a full quart, into his radiator one time. Had to get all chemically cleaned out.

 

[BaySHO Performance]

Maybe someone will know what being "off" means on a balance test.

During KOER, there's as option to do a cylinder balance test. The computer cuts fuel to each cylinder in turn, and measures the drop in RPMs. If the drop isn't as big as expected, it will indicate the weakest cylinder, although more than one may have a problem.

In addition to the aforementioned possibility of a bad plug or wire, or a clogged injector, it may indicate worn rings
(or a burnt valve, but extremely unlikely) in that cylinder. A compression test will tell you. Pressure should be around 205 - 210 psi with the lowest cylinder being acceptable if no less that 85% of the highest (IIRC). If adding a teaspoon of oil to the cylinder makes the compression go up, indicates worn rings.

 

[NoSlo]

This is the 91+ I went up to Indianapolis to get back in March; the one I've been making all the new posts about. I'm not sure on the history, and haven't done a flush. I know the PO did put in a double core radiator at some point, as well as a 3.2. That slimy black gunk sounds like what's in mine. Did you figure out what it was or where it came from? Can the oil cooler system leak into the coolant?

The oil cooler is a solid metal shim that goes between the oil filter and the engine block. External coolant hoses feed coolant through it. There's way too much metal that would have to fail in order for coolant to get to the oil; there's no seals or gaskets between coolant and oil there.

The transmission cooler is a soda (or Red Bull) can-sized block of metal that is inside the radiator with external hose connections, also extremely unlikely to fail.

The SHO simply doesn't have idiot designs of other models - like the waterpump takes out the timing belt or leaks into the oil. There are few places other than the head gasket where coolant and oils might meet.

Recommend a full flush - we are talking pull out the thermostat, disconnect heater core hoses and lower radiator hose, and blast garden hose water through everything both directions until it runs clear. Run the engine until hot with chelating flush additive and water, and hose rinse again. Fill with coolant mix, and burp bubbles by detaching a throttle-body coolant hose and topping off until those drip.

Only if oil returns under known conditions would I then go to a static cylinder/crankcase/cooling system pressure leakdown test. The head gaskets are just too bulletproof to initially suspect.