Mystery oil leak....any one?

So here's the info on it....new rebuilt engine, fresh MLS head gasket, block decked, head perfect. oil seems to be coming from under the exhaust manifold on the right side. Thought it might be coming from the head gasket or one of the head studs??? Car runs perfect...no smoke, nor does it overheat. Pushing 23psi of boost with no problems.

 

[ktmrider]

IIRC one or more of the EM studs goes into or near an oil galley.
You may need to R&R with some thread sealant if someone can confirm this...

 

[sixsixtwo]

Had that happen once when oil was getting past the piston rings. Considering it's a freshly rebuilt engine I doubt that this is the case, but it is a possibility. Maybe the rings aren't seating right?

 

I believe KTM is right, the center stud on the lower plain goe straight through to an oil galley... If the aluminium starts to stip out of the head you may have trouble. Happened to me, but I was lucky. Ran a tap into the head a few times to clean it up and Hi-temp permanent Loctyte'ed it w/ new SSStuds.com. the center stud was leacking, but the trail of oil was coming off the exhaust gasket near the power steering pump.

 

[turbowop]

I'm impressed by the amount of oil that can leak through that stud if it's not sealed, considering that it's not under pressure and is just a oil drain back to the pan. /ubbthreads/images/graemlins/crazy.gif

 

[bazeng]

I had a water leak there after my rebuild. It was leaking past the threads of the water pump bolt..

Some loctite fixed it....

 

[Wizardawd]

Quoting turbowop:
I'm impressed by the amount of oil that can leak through that stud if it's not sealed, considering that it's not under pressure and is just a oil drain back to the pan. /ubbthreads/images/graemlins/crazy.gif



Technically there will be as much pressure as your rings allow correct? The same pressure that pops out the worn out dipsticks will also force a little extra oil past threads and seals.

Wiz

 

Quoting sixsixtwo:
Had that happen once when oil was getting past the piston rings. Considering it's a freshly rebuilt engine I doubt that this is the case, but it is a possibility. Maybe the rings aren't seating right?



No the rings are perfect and if they were leaking I would be getting smoke out the exhaust!!! There is absolutely no smoke what so ever.

 

Quoting kryger:
I believe KTM is right, the center stud on the lower plain goe straight through to an oil galley... If the aluminium starts to stip out of the head you may have trouble. Happened to me, but I was lucky. Ran a tap into the head a few times to clean it up and Hi-temp permanent Loctyte'ed it w/ new SSStuds.com. the center stud was leacking, but the trail of oil was coming off the exhaust gasket near the power steering pump.



Buschur Racing did the head and if I remember they put that tread sealant on all the studs. But i had the head cleaned recently...the hot tank could have removed the sealant?? When the engine cools down if I put my hand up under the exhaust mani I do feel oil on the back side of the exhaust gasket towards the middle. I think the stud in the middle is leaking like you guys said. It is hard to believe that all that oil would be coming from the head gasket. I will take the mani off and have a look.

 

IMO... Definatly run a tap through (8m x 1.25) but you need the head off to the alu. shavings don't go on a fantastic voyage through the oil return system. Also remember there are like 30 different types of Loctyte
Graninger Industrial Supply (click)
ok I lied, there are 48...

 

besides Alu (head), carbon steel (manifold), and SS (studs) all have completely different expantion rates... So the the stud might just not be threaded in as far as it needs to be. An oil @ start-up or is there more when the car is warm???

 

^ "any" oil @ start-up??

 

Quoting kryger:
besides Alu (head), carbon steel (manifold), and SS (studs) all have completely different expantion rates... So the the stud might just not be threaded in as far as it needs to be. An oil @ start-up or is there more when the car is warm???



The oil seem to only come out when I drive it hard, after it's warm. I can't physically see it drip out when the car is sitting at idle.

 

i hope that maybe when you installed the manifold, the stud pulled out a few threads... could be that simple. OR NOT

B/C if you dont have that stud in at all... it pukes like half a quart in

 

Quote:

bazeng
G'day mate!


posted 10/07/08 02:00 AM
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I had a water leak there after my rebuild. It was leaking past the threads of the water pump bolt..

Some loctite fixed it....




I can't remember exactly, but there is something in Synthetic oil that can eat through silicon based and other sealents... I'll do some homework

forgot to mention b/4 I put some Liquid Metal stuff, made for alu, that expands @ the same rate, in the backside of the stud (in the oil gally)... but i also had the head off the car

 

liquid Aluminum CLICK
here is the stuff I backed my stud w/, along w/ Hi-temp permanint Loctyte

 

Holly crap dude that stuff is expensive!! I think I'm gonna just take the mani off and take the stud out put some thread sealant in it and see what happens. I still need to confirm that its coming from the stud.

 

Pretty sure I fixed it. Took it to the track tonight and ran a 12.3 1/4 mile /ubbthreads/images/graemlins/smile.gif

 

[bazeng]

nice time!!

what was the issue?

 

It was either the bottom middle exhaust stud or it was leaking through the head gasket...I pulled the manifold off pulled the stud out put thread sealant on it. I also pulled the valve cover off and got the front middle head stud tighter.