Right chaps,
As some of you may know i recently rebuilt my g40, I have had it running or a while and clocked a slow 650ish miles taking it easy staying off boost up until 500 miles. Slowly I have been accelerating faster but only reaching 0.5 bar boost max.
But i pulled up after my last trip and there is oil all down the side/back of the block and on the gearbox casing :(.
Now I'm not sure whether the head gasket is slightly dodgy or whether the head bolts are the wrong type or whether the head bolts need tightening up again once being run for x amount of time?? As the oil seems to becoming from between the head and block and it's only had a new gasket when the rebuild was done.
Any advice would be greatly appreciated as I have spent a lot of time effort and money getting my G going again and its throwing it's toys out of the pram already.
Thanks Jake.
Afaik the headbolts don't need a 2nd torque after running. Have you lost any water or power? Was the head skimmed & block decked (if required)?
Are you sure it's leaking from there and not the cam cover or spraying out of a breather and just collecting on the joint of the head n block?
not a leaky rocker cover? or dizzy seal?
I thought as much, i was afraid that this was the case. There doesn't seem to be any lose in power/water, I didn't get the head skimmed as i didn't want the compression ratio to change too much but I did use a flat block and emmery paper to flatten any high spots.
Pete - Its not a leaky rocker cover but it does seem to be coming from the dizzy seal sort of direction i haven't had chance to properly have a look. I'll get in there and have a proper look tomorrow.
It's a flat head, its not going to affect C/R by a significant amount. Are you sure the torque wrench you used is good? Maybe just check the bolts?
Had a good snoop around today lads, also did a compression test on all cylinders.
1. 10.5 psi
2. 10.5 psi
3. 10.5 psi
4. 10.5 psi
Then when checking around the back of the head I found one of the oil pressure switch's was really loose. So cleaned it all up and fingers crossed the problem should be solved :).
That will absolutely piss oil out if they were loose. I had one fail and there was oil everywhere.
When we were first cranking the engine over making sure the oil was getting around we pulled the pressure switch out and yeh it does fly out of there.