oil floating in coolant

[slowpokedodge]

Bought a 99 f250 4wd last month, got tired of getting stuck in the winter time. Anyway It doesn't crank good when it is cold so I was checking the gpr. It seems to be working, having a time trying to get to the glow plug wiring to check them.I noticed my coolant looked dirty so I took the cap off the reservoir and there is a very thin layer of oil floating on top. I can shake it around and it will disappear then come right back. Any ideas as what that could be? I hope I didn't buy a lemon, its got 190000 on it.

[PowerStrokeBren]

Could be the head gaskets going out.

[sinner6.0L]

oil cooler or I've seen really bad ones be an injector cup

[slowpokedodge]

Is there a way to tell which one it could be?

[444 ci]

if its oil in your coolent its your oil cooler.the o rings are bad or your oil cooler is rusted out on the inside. my truck did the same thing and my oil cooler was bad is your truck losing oil? if your injector cups are cracked you will have diesel fuel in your oil. the head gaskets rarely go bad on a 7.3 ill lay money its your oil cooler.

[screwatts]

Oil cooler , if its an injector cup you wouldn't be able to make out oil in the Coolant. Go rent a coolant pressure tester from advanced.

[screwatts]

This is what coolant looks like with a bad injector cup

[slowpokedodge]

Thanks, looks like its going to be the oil cooler.

[screwatts]

No problem lets lit know how it turns out.

[jermcd]

Good info guys. Thanks too.