Oil in coolant; Oil cooler appears OK

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cobra4v04

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2014 Raptor bought new, engine is 100% stock, at 105,000mi

Going through another oil mixed with coolant scenario with my Raptor. Two and a half years ago at around 75,000 miles I noticed the coolant overflow tank was a mess of brownish sludge. At that time I had an inhouse mechanic available to work on it and after getting into it the oil cooler was determined to be allowing oil to mix with coolant. I was told he pressure tested the oil cooler and verified a leak, don't know how he tested it but ultimately the cooler was replaced, the engine/radiator/hoses flushed repeatedly and everything put back together. Up until a month ago all was well until I went to check my oil and saw the overflow tank was a brown mess of sludge again.

Of course my first thought was the oil cooler, and this time my mechanic was not available on short notice so I began looking at fixing it. Engine oil looked good, no signs of any mixing with coolant. Transmission oil cooler lines also had no signs of mixing with coolant. Upper radiator hose was thoroughly coated with a thick sticky brownish goo, has a distinctive oil smell versus coolant smell. Under the assumption the oil cooler was bad I went ahead and ordered parts; upper/lower/heater hoses, thermostat/housing, oil cooler. Almost like deja vu the availability of the oil cooler was limited, same as I experienced two and a half years ago, and as mentioned by other posters. I was told they are made in Manitoba and production was two weeks out and expect another week getting through customs. I managed to track down a dealer in Orlando that had one and would sell to me, other dealers I called that had them said they were not allowed to sell as the parts were for their customers vehicles in their repair shops. Even a couple of the hoses were on backorder. In the meantime I pulled the oil cooler and cleaned it up, degreased and inspected it, no signs of any damage. I set up a pressure test and submerged the cooler in a five gallon bucket of water with the cooler pressurized to just shy of 60psi and had zero bubbles after a couple minutes. Unless there is a factor of high temperature influencing some type of leak in the cooler I don't think the cooler is bad.

One other area I see as a potential source is the oil filter adapter housing. This appears to be only other location, aside from internally, on the engine where oil and coolant are in close proximity. The housing itself could potentially be a casting that has enough porosity between the oil and coolant passages to allow oil to force its way into the coolant. There are also two gaskets that could possibly be bad. I've had other issues with these oil coolers in the past, years ago my 2001 Cobra suddenly began streaming a high pressure jet of oil at the ground beneath the oil filter, turned out it was an oil cooler casting that visually looked "bad" as far as surface texture.

Anyone have experience with an oil filter adapter housing going bad?
 

BossRaptor

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I had the exact same issue with a cobra oil cooler/filter housing back in the day in a mustang. And oil is a PITA to clean out of the cooling system! I have not noticed this issue with the Raptor at all. Ill keep an eye out for it tho! Thank you for the heads up.
 
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