c20let head leaking oil

[bilcon19]

Anyone help me with an annoying problem i have. Ive recently rebuilt my let in my astra and apart from a few little problems everything was fine till i started to get an oil leak. I started to notice it on my manifold and it got worse so thought it might have been cheap rocker gasket so bought a gm one didnt make a differance and by this time it was really bad started to smell it in car and smoke would start to come from bonnet. So looked more into it an found that one of the small core plug on front was leaking and quite loose so i removed turbo and replaced them all while it was of again with genuine gm one's this i thought had fixed it the was a bit of oil on it but just thought that was what was in the gasket but its getting worse!!!! anyone any other ideas????

Cheers

[GaryB]

Perhaps camshaft seal(s) or oil filler cap ( can leak badly, runs out at the front of the head from underneath the 'L' spark plug cover - 2 minutes to change with a new two bob gasket).

[c20letian]

i put a tiny bit of silicone sealant bitween the cam cover and rubber seal then some sealant on the head and put the cam cover down...
all my non moving part oil seals are fitted this way and never have any leaks.

[bilcon19]

Thats the thing dont think its cam cover and it defo aint cam seals as the oil is on the manifold and no sign's of the oil running down it looks as though its coming thru the exhaust gasket an just sitting on manifold till it gets hot it weird because theres no other signs were its coming from.

[seanr28]

correct me if Im worng, but I thought the core plugs were for water water?? Try the grub screw on the front of the head, that definatley an oil way.

[maldred]

dont use silicone sealant on a turbo engine

[seanr28]

dont use silicone sealant on a turbo engine

RUBISH! completly fine, as long as you dont go mad with the stuff!

[CrashTestDummy]

There is an oil gallery plug on the exhaust side of the head between cylinders 2 and 3. Apart from a leaking cam cover gasket that's the only way that you will get oil onto the exhaust manifold.

[Davey j]

My bet is a pinched rocker cover gasket! Undo it all, clean it up, re-fit and torque down properly. Should be right.

[bilcon19]

nope an nope lol there no signs of oil coming down the head its spotless ive just rebuilt it and cleaned everythin 1500miles ago id see it if it was cam cover gasket and i can see grob screw thru exhaust gasket and thats clean its really doing my head in think im gonna get original head repaired that went pourus and swap them back anyone know who does a desent job at repairing them an another quick question should the return hose off the turbo allways flow water to header tank or not???

[nova2l16v]

Hello,
Did you ever get to the bottom of this? I have exactly the same problem!

[nova2l16v]

bump

[bilcon19]

nope still trying really annoying aint it lol

[nova2l16v]

Hello! well Ive solved mine, took it to vaux! the core plug was leaking coolant onto the manifold this mixed with the gunk around the head caused the smoke/smell.
apparently apart from the oil grub screw this is the only thing it can be if its coming from that area, failing that you have a hairline crack in the head.

[mac1976]

you sure its not the turbo oil feed pipe thats not leaking

[bilcon19]

no its only on top of manifold so it aint feed for turbo and ive changed all the front core plugs in head think it might be head its self i need get my other head fixed it went porous but dont no were to get it fixed

[Frisco]

Or if the oil shows up on the head of one of the manifold bolts there is a chance you have overtightened the stud and cracked into the oilway

[bilcon19]

well when i was rebuilding the head i noticed a few of the manifold threads had been heli coiled so there a chance who ever did them theres a chance they could have gone in a bit to far either way im gonna put original head back on i think still dont no were get it fixed though.