I may or may not have an emergency. Last winter I had oil in coolant mixing and ended up doing an engine swap like the garage recommended (had the old engine pressure tested and it was fine, my buddy has it in his vehicle now. Ended up being an oil cooler) but when I flushed my radiator for the new engine I never flushed the heater core. 1,200 miles ago I did an oil change. I know I have a small leak and checked my oil today. It was about 1/8" low. Which seemed normal since it was leaking. But I noticed my coolant looked dark. I dipped my finger in it and sure enough there was oil. I let my truck sit and checked the oil in the oil pan and it looked fine. No water. It's been getting down in temperature since my oil change and I've been running the heat the past few weeks. Could there have been enough sludge in the heater core that it would fill up my degas? Should I be worried?

 

use a paper towel to soak up oil and drive it, you should see the amount decrease over time check the cooler and see if oil on it you may have another cooler that needs seals

 

maybe there is residual in heater core but that usually has coolant flow some what unless you have a manual valve on it.

 

It has on a brand new oil cooler and o rings. Didn't replace the caps. And I just got the engine put back in it 2 months ago and it had a little oil build up in the degas. Just a thin film on top.
I drove the truck 22 miles to and from work today. No problems. Checked the oil level and coolant level before and after. They're both at the same spot. I'm gonna drain the degas and fill it back up with new coolant and keep doing that until I'm out of oil in my pan or the oil in the degas goes out 😬

 

Repeatedly draining and filling just in hopes of getting all the oil out is a potentially very expensive process. Anti-freeze is a lot more expensive than water. How thoroughly was the cooling system flushed after the oil cooler R&R? If it was just drained and refilled, that would explain the latent appearance of more oil. I would do multiple flushes with tap water, then flush once or twice with distilled water (to get the tap water out), then drain and fill with full-strength anti-freeze plus proper SCA (or pre-charged anti-freeze) and distilled water.

 

When I did the cooling system I just flushed the radiator 4-5 times with dawn dish soap and purple power. The heater core wasn't flushed.

 

If you only did the radiator, you left a lot of oil in the coolant jackets in the engine. Fill/drain and/or flush the SYSTEM (block, radiator, hoses, heater core), replace all soft hoses, and go from there.

 

The engine didn't need flushed. It was a good engine that I dropped in.

 

Well now it needs flushed.

 

I flushed the coolant about 800 miles ago now and checked it 3 days later and it looked fine. I just checked it today and my degas is full with oil and I'm just on the add 2 quarts mark. I have a small leak somewhere. Any ideas where to start? There's no coolant in my oil just oil in my coolant.

My truck is running stage 2 injectors and it's chipped but I don't run it too hard and it never sees above 1100 egt's and I keep my boost below 25 lbs.

 

oil cooler and injector cups would be my first to look at

 

If it were cups wouldn't it be fuel in my coolant?

 

Depends on where the Crack is.

Remove injectors and pressurize the coolant for a few hours and see if it leaks