Oil In Coolant

[kidafa]

A little over a month ago I noticed oil in my coolant, not much and there was no sign of coolant in the oil....

Had a compression test and Tekay test done. Tekay test showed there were no exhaust gases in the coolant.

Compression test results were:

1. 155 2. 160 3. 135 4. 145. 5. 160 6. 160.

So a couple of mechanics gave me advice on an assumed blown headgasket/small leak between cylinders 3 and 4.

I had the head removed, machined and crack tested and all checked out OK.

Had it all put back together with a new headgasket, head bolts ect.. and had the cooling system flushed ect and all was ok.

3 weeks later and the car has had NO hard driving and I've got oil in the coolant again. What could this be?

The car is manual so no auto trans fluid going through the bottom of the radiator. According to the mechanic who changed the head gasket there is no factory oil cooler/warmer set-up on my stagea so its not that mixing the oil.

There is NO sign of coolant on the dip stick or under the oil cap at all.

Thanks in advance guys and apologies for the lengthy post,

Chris

[The Mafia]

The deck can be warped too. If the head is flat and the desk is warped, it will do the same.

Did you check the flatness of the head while it was off?

[kidafa]

I didnt personally do the work but I'll find out if the flatness was checked, I doubt he would miss it as he's been in the RB game for a long time.

[zebra]

cracked head or a split bore is possible.

But I doubt it due to 3 weeks of being ok.

I agree with above that the block deck might not be straight.

What head gasket did you use?

[kidafa]

OEM Nissan HG

The headgasket that was removed had no signs of any leaks/damage as well :S

[zebra]

Turbo cartridge dead? its a long shot but possible

[kidafa]

Turbo cartridge dead? its a long shot but possible

Yeah Ive also thought about this.... How could I test it?

[The Mafia]

Also - Did they use hylomar?

[Rolls]

Do a comp test, otherwise we are just guessing.

[wolverine]

Do a comp test, otherwise we are just guessing.

What, like this....

OP posted this already.

Compression test results were:

1. 155 2. 160 3. 135 4. 145. 5. 160 6. 160

[kidafa]

That was the test prior to replacing the hg

[wolverine]

oops, apologies.

[Rolls]

Lol I was waiting for someone to do that

[The Mafia]

sounds like the deck - between 3 and 4 are the most likely to have a dip.

The mechanic should have checked it. IT might have run ok for a little while but was weak, and broke easy.

[DVS JEZ]

Like i said in your other thread, do a compression test to see if the comp has improved since the new headgasket

[Simon-S14]

i did the work.

the head was crack tested, straightness tested and machined. the deck was checked in several places with a straight edge. OEM gasket kit was used and no hylomar. Brand new nissan headbolts also used.

im personally leaning towards a block fault the bores all looked fine when i had the head off. however no further dissaembly was done.

[Simon-S14]

sounds like the deck - between 3 and 4 are the most likely to have a dip.

The mechanic should have checked it. IT might have run ok for a little while but was weak, and broke easy.

i couldnt find any faults on the deck to cause a compression drop. nore was there any trace of tracking on the surface of the deck or the head. the headgasket looked fine also. no visable evidents or any teltale signs

[The Dan]

check the factory oil cooler on the standard oil filter mounting plate. The seal might be f**ked inside. Oil and water mix at that point

*edit* and unless a wet comp test or leakdown was done, stop guessing about compression problems. If it was a warped deck you are more likely to get oil and water mixing both ways and going into cylinders. Warped blocks are rare....so rare in fact I have never seen one except a 1JZ making 1k hp that had a decent explosion in the cylinder which squashed a piston

and if there WAS a dip between cyl 3 and 4....that would have nothing to do with oil in the water

If there was oil in the water galleries as well, sometimes it can take some time to work its way up to the cap. How bad is the oil mixing in the water?

[Simon-S14]

check the factory oil cooler on the standard oil filter mounting plate. The seal might be f**ked inside. Oil and water mix at that point

*edit* and unless a wet comp test or leakdown was done, stop guessing about compression problems. If it was a warped deck you are more likely to get oil and water mixing both ways and going into cylinders. Warped blocks are rare....so rare in fact I have never seen one except a 1JZ making 1k hp that had a decent explosion in the cylinder which squashed a piston

and if there WAS a dip between cyl 3 and 4....that would have nothing to do with oil in the water

If there was oil in the water galleries as well, sometimes it can take some time to work its way up to the cap. How bad is the oil mixing in the water?

not all stageas (if any) come with the factory oil cooler arrangement.. they have the RB20 style bolt on oil filter arrangement. so that rules that out. trust me was the first port of call for me

[kidafa]

Thanks for all the response guys, Ill do another compression test tomorrow and post up the results....

Is it possible for the turbo to be mixing the oil? I initially thought it was but after reading the following thread, it doesn't sound like its possible

http://forums.nicoclub.com/oil-in-coolant-damnet-t490685.html