Oil mixing with coolant- new RB25 build

[maximajim]

nothing but problems after problems..

Right now the oil is mixing with the coolant. And It smokes when reved. At idle it does not smoke.

Before the intial install I:

1) checked the head for flatness

2) used a fresh Metal HG and sprayed with copper

3) had the head milled to flat

I did however reuse the stock head bolts. I did not check them for stretch. Would they cause this problem?

[DAN00H]

I have reused head bolts in other cars (no boost) and they worked fine. are you sure the gasket is the correct one? Check all the oil/water lines to the turbo (is the turbo in good condition? did you connect the oil / water lines to the right places?

[RB26zcar]

Are you supose to spray a new metal HG when you install it for the first time? I bought a Tomei metal gasket set, and I'm fixin to mate the head with block, but now I want to make sure this is nesesarry....

I did have the same thing happen to me once re using a HKS metal HG,and my mechenic told me it was because I used copper coat spray.

He said that copper spray is for exh flange use only, and it won't seal any fluids...

But I see people saying that use it on HG's all the time, so whats the real facts...??

I'd like to be 100% before I bolt my head on... HELP :burnout:

thanks

joel

[BBQ]

Did you get your block decked ? If not that’s probably the problem, Your gasket won't be sealing properly, also did you use the correct tension settings for the head ?

Using the same head bolts shouldn't be a problem, Have done so in 2 cases. As long as they were installed correctly, eg stretched first, then tensioned, and so on.

Have you checked your cylinders to make sure no water is leaking into them ? Also check to make sure you haven't got and lines around the wrong way, eg turbo lines, water line going into oil inlet on block and so on.

I'm intrested to know if you find the problem. Good luck

[Cubes]

I used a Multilayer Cometic metal head gasket. It has an oring setup in the middle layer.

It specifically states not to coat the headgasket with anything. Just use the headgasket and thats it.

[PurpleR32]

did you over - overbore?

[Sydneykid]

Oil in the water indicates a leak from the oil gallery to the water jacket, this is possible because the oil is under pressure, more pressure than the water. When you stop the engine the oil pressure will go to zero, but there will be pressure still in the water system, until it cools down, around 20 psi depending on the radiator cap. So if it truly has a leak from the oil gallery to the water jacket you will get water in the oil as well.

A simple cooling system pressure test will tell if this is in fact the case, connect an air pump where the radiator cap goes and pump it up to around 20 psi. Watch and see if the pressure stays up, if it drops away then you have a leak. Sometimes you can actually hear where the leak is, they cost about $US70.

This may not be related to the smoke, easy way to check that is with a simple leak down test. Connect compressed air up to the spark plug hole in each cylinder (one by one) and see if it leaks. Once again you can generally hear where the air is escaping from. You can buy a leak down tester for $US60.

Your local friendly workshop should have both of these, maybe you can borrow.

Hope that helps:cheers:

[RNS11Z]

I had the same problem. Turned out to be my copper head gasket was r**ted. Water and oil was mixing during cold starts and on idle. Not long after motor went boom.

[ace_nz]

on rb25s with the vvt the oil gallery at the front is very close to a water jacket, make sure your gasket is correct in this area. All the RBs have non torque to yeald head bolts so theres no need to replace them. Also check oil cooler, uncommon for them to fail, seen it happen on a few subarus though.