Coolant in oil after fresh rebuild

[Noleboy55]

Hey Guys,

Just recently put together a fresh 2.7T motor with rebuilt heads, freshly decked and hot tanked block, etc...

The problem I'm having is that coolant is getting inside the oil. Within 60 seconds of starting the car the first time the oil looked like a vanilla milkshake.

Checked the oil cooler under pressure and it's fine, replaced the rear main seal AGAIN just to be safe, and now I'm pulling the heads to check for the possibility of head gasket damage. So far everything looks good

Can anyone tell me where else coolant might be getting into the oil??

[slowSfaux]

Cracked block, cracked head, rear main seal flange gasket, and oil cooler are the most probable culprits.

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And obviously the head gasket.

[Zba]

Pressure test you cooling system before ripping and tearing. I assume this wasn't happening before? Is this a 6MT or a Tip?

[MacDaddy]

Rear main seal flange gasket

[Noleboy55]

Hey Guys

Thanks for the responses.

It's a 6 speed MT car. Went ahead and replaced both head gaskets just to be safe. We'll have the motor back in tomorrow so fingers crossed!

Does anyone know how long it'll take to clear out all that water? I assume 2-3 oil changes at least.

If it's still leaking I'll definitely pressure test it this time!

[MacDaddy]

If it was HG you generally end up with oil in coolant, and overheating.

[slowSfaux]

If it was HG you generally end up with oil in coolant, and overheating.

Not necessarily. Coolant leaking past the head gasket directly into the combustion chamber will run down the cylinder walls and past the piston rings, then into the crankcase where it'll mix with the oil.

It's possible to leak between a oil feed passage into the Coolant as well, but because there isn't oil in the Coolant isn't reason to rule out a head gasket.

[S4James]

Not necessarily. Coolant leaking past the head gasket directly into the combustion chamber will run down the cylinder walls and past the piston rings, then into the crankcase where it'll mix with the oil.

It's possible to leak between a oil feed passage into the Coolant as well, but because there isn't oil in the Coolant isn't reason to rule out a head gasket.

he'd have a shitton of white smoke if that was the case

[slowSfaux]

he'd have a shitton of white smoke if that was the case

Correct, but he'd have none if the leak was between a Coolant passage and an oil drain passage. I'm not betting my money on the head gasket, I'm merely saying not to rule it out.

[Audi9]

Everybody is so quick to load up the double barrel lol

[slowSfaux]

Everybody is so quick to load up the double barrel lol

The op specifically asked where coolant could enter the oil from. I told him the possibilities, although I am in agreement with macdaddy on the rear main seal flange. This motor likes to leak there if you don't get it just right and/or use a ton of sealant.

[Audi9]

The op specifically asked where coolant could enter the oil from. I told him the possibilities, although I am in agreement with macdaddy on the rear main seal flange. This motor likes to leak there if you don't get it just right and/or use a ton of sealant.

Haha I just thought it was funny how quick people were saying to replace this or that. Everyone is on the right path but I think it best to look first and find the point of failure before ordering parts. Especially with something like this

[M551_Sheridan]

What was the outcome, did this issue clear up?