2G Oil and coolant mixing

[Jay braze]

My Eclipse GSX build was finally completed and on the 1st start up oil was coming out of the turbo so we turned off the car and oil and coolant were mixed. Nothing is mixed in the top half of the engine, only once it passed through the turbo was it mixed. I sent the turbo back to forced performance who ran a leak test and found nothing wrong.

But if it was a head gasket wouldn't I have oil and coolant mixed in the top end?

The next step I guess is to run the engine without the turbo and see if oil and coolant are getting mixed. My mechanic says there's no way its not the turbo. But just seeing if anyone knows or can explain how it would be the head gasket and not the turbo if nothing is mixed before going through the turbo.

Am I missing something?

 

[99dsmer4g63]

Check the oil cooler where the oil filter bolts onto the oil filter housing.

-Daniel

 

[dwb]

If turbo and head gasket are good, check your oil cooler. If that gets torqued too tight it will crush and allow the oil and coolant to mix.

 

[chrysler kid]

Nothing is mixed in the top half of the engine, only once it passed through the turbo was it mixed.

How could you tell where the coolant was mixed, the whole system should be contaminated.

Run the turbo without coolant to it, the turbo does not mix the oil and coolant

Youre missing something. Sounds like your mechanic messed something up rebuilding it

 

[chrisman287]

I would drain oil and coolant to determine what’s really going on.

 

[Mikealj]

My Eclipse GSX build was finally completed and on the 1st start up oil was coming out of the turbo so we turned off the car and oil and coolant were mixed. Nothing is mixed in the top half of the engine, only once it passed through the turbo was it mixed. I sent the turbo back to forced performance who ran a leak test and found nothing wrong.

But if it was a head gasket wouldn't I have oil and coolant mixed in the top end?

The next step I guess is to run the engine without the turbo and see if oil and coolant are getting mixed. My mechanic says there's no way its not the turbo. But just seeing if anyone knows or can explain how it would be the head gasket and not the turbo if nothing is mixed before going through the turbo.

Am I missing something?

Most of the time this is a result of your oil filter housing having a leak. Some times these crack and the oil gets pushed into where the coolant goes around it to cool it.

 

[Jay braze]

The engine was fully built, its a 4gcs stroker motor, hks 272 cams, top end was machine shopped. It's possible the gasket was bad but really hope it's not the head gasket. Gonna run the car without the turbo and see if it's getting mixed still. Gonna check the oil cooler as well, which I'm thinking/hoping could be the problem. I'll post an update once I go through it

 

[jakk220]

9/10 times it's the head gasket. Save yourself the trouble and do a leakdown test. If FP says it's not the turbo, then it's not the turbo. They're reputable. Plus that is super rare and uncommon. Could be the oil cooler, but probably won't be the case.

Oil and coolant don't only mix in the top or bottom end. If your mechanic told you that, and he built this motor, then you can bet your last dollar he has no idea what he's doing and there's probably countless things he messed up. He's already sketchy for telling you "there's no way its not the turbo". Because he is either dumb or he doesn't want to admit it's the headgasket.

 

[pauleyman]

What's the history of the oem parts installed? Known?

 

[chrysler kid]

The mechanic saying its the turbo is what tells me you dont have a good mechanic