R.B.

Can anyone list all the places were coolant and oil can mix and how to test which place is the culprit?

After my engine rebuild and redoing my head gasket again, I am getting coolant in my oil. I am not sure how to proceed. I am getting a milky mixture leaking from somewhere around the oil filter assembly or the balance shaft. And I have a couple of coolant leaks which I have not found yet. My exhaust won't stop smoking in the engine bay either. Arrgh!

-R.B.

M758

1) Headgasket
2) Oil Pressure relief valve/Oil Cooler line cover plate
This is the location of the oil cooler on the NA cars. Turbo cars have just plate and the external cooler, but still retain some seals in that area. These can leak like they do on a NA and cause mixing.

Perry 951

Cracked block or cracked head can allow coolant to mix, depending on where the crack is.

I would suspect the oil cooler housing. Perhaps you nicked an O ring on the install? Easy to do, PITA to fix.

R.B.

I guess I should have worded my question a little differently. Yes I know, the head gasket and oil cooler assembly are 2 places this can occur. How do I diagnose which is the problem? I have coolant in my oil as opposed to oil in my coolant. Does this lend itself more to oil cooler or head gasket. Since I just re-did the head gasket, and I don't have coolant in my cylinders, compression is good, my head was just done during my rebuild so I am assuming no cracks etc. I checked the surface again for straightness when I redid the head gasket.

So, how do I diagnose this?

Thanks,
R.B.

Florida951

I also had only oil in coolant. After I did the hadgasket i found out it was the oil cooler seals, changed those, problem solved. Have fun!

Perry 951

Coolant in oil.. that is usually a head problem. Have you checked the surface of the block to be sure it is true? You know the head is flat, but what about the deck?

Oil cooler seals usually have oil in coolant VS a milkshake.

R.B.

Yes I checked the block too. (sorry I should have mentioned it). I was very careful the 2nd time putting the head on, making sure cleanliness and torque were done right. I still hear the "20Nm 90 90 and forget it" bouncing around my head

What's my next move?

-R.B.

Perry 951

The 20/90/90 is fine. I think it would be worth changing out the seals on the oil cooler housing and the pressure relief valve. The kit is cheap, but the big thing is the pain in the *** that job is. Fill it up with some dino oil and water and see what happens. If all is ok, then change the fluids with what you normally run.

If that does not help, you are going to have to go back into the motor and try and find where the problem is.

I wish I had a better solution.

R.B.

Thanks Perry,

I figured I would be taking the oil cooler housing apart. That is a section that I did not do. The place that worked on my crank and head replaced the seals in the oil cooler area. I should have redone it myself but did not realise at the time that I needed an alignment tool. I am sure that the shop did not know that either.

Any words of advice on tackling this. Can I leave the hoses on and just remove:
- heat shield
- wires to pressure sensor
- oil filter
- 4 bolts holding housing

You mentioned "Fill it up with some dino oil and water and see what happens. If all is ok, then change the fluids with what you normally run."

Are you talking about filling up just that assembly some how or re-assemble the motor, fill up the motor with fluids and start it up again? or is there away to test that I did it correctly without running the motor?

-R.B.

kelsean

[quote] I should have redone it myself but did not realise at the time that I needed an alignment tool. <hr></blockquote>

Is the alignment tool absolutely necessary to get this thing on without leaks/mixing?

R.B.

I have spoken with some people that have done it without. But I think since I will be redoing it that I will get the alignment tool.

-R.B.

Perry 951

You really do not need the alignment tool on the '87 1 peice units. You can use the valve itself as the alignment tool. The workings of the updated valve are inside the valve, so misalignment is not a big issue.

You will have to re-assemble everything and run it to see if you fixed it. There really is no way to get pressure into the system to check.

Getting that shield off to access the bolts is the hardest part. You can leave the hoses on, bu be careful not to crimp them when you seperate the housing from the block.

R.B.

Thanks Perry,

I know about the heat shield, when I put my motor back in, I was left with the heat shield off, not knowing where it went. I figured I would figure it out later. I found a picture posted by another rennlister and recognised the shield and where it went. I managed to get it in there after removing the exhaust manifold again. I am getting pretty good at it. I have removed it 3 times during my rebuild. <img src="graemlins/c.gif" border="0" alt="[ouch]" />

So when I pull the valve off, does the seal come with it or is it in the hole. When I re-install it, do I push it in and then let the valve seat it or put it on the vlave and insert together. Sorry for being ignorant, like I said this about the only part of the engine I did not pull apart myself.

-R.B.

Perry 951

It is not too bad. Here is my process from memory.

1- Drain Coolant
2- Remove heat shield
3- Remove Oil Pressure Relef Valve from housing (just unscrew it and remove from the housing)
4- Remove Housing
5- Clean mating surfaces and pressure valve with brakekleen
6- Install Gasket on housing (coat lightly with oil) and install 4 bolts finger tight
7- Install New O Rings on Valve and coat valve and O rings with oil
8- Insert valve into housing and block and tighten 3/4 of the way. (This will align the housing
9- Tighten 4 bolts on housing to spec (15ft/lbs IIRC, but could be more.
10- Remove valve and re-install. Should slide in with ease
11- Put everything back the way it was.
12- Run it and hope there is no more mixing.

R.B.

Another question: If I am just replacing the seals on the pressure relief valve, why do I need to remove the whole assembly. Can I just not remove the 20mm bolt and pull out the valve, replace the seals and reinsert?

-R.B.