Headgasket not seal! Swap HG if engine in or out?

T

Thor

Member
New starting engine problems

Hello!

after we put the new engine in my car we have checked all and started. But after few min we found a oil leak under the car from the exhaust coming and there was oil on the pistons!!!!

There was fitted a cosworth 1.5mm headgasket and my engine builder has fit the HG with the nissan manual. He had torqued the bolts 2 times and than loose all 360 deg. Then he had torqued up to 127NM. But is it the right way too fit the metal head gasket??

I think the head gasket is the problem and do not seal now!

Is it possible too swap the HG if the engine still is in the car? The big black rear brackets i not have fit again at the rebuild, so it must be easier i mean.

regards
Sascha
 
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red reading

red reading

Active Member
You are supposed to torque up once, (and leave it for a day as I do) slacken all bolts off, tighten to 38lbft and then go thru 95 degrees......just torquing up to 127 nm is inaccurate I tested it....ps did you cote the bolts with molyslip grease as well?
 
T

Thor

Member
He had put the bolts with oil in the block!

The question is, if the HG is the oil problem? There comes much oil out of the exhaust manifold and we had seen them on the pistons too!
 
johnny gtir

johnny gtir

Well-Known Member
sounds like it. When you say new engine full rebuild head and block true prior to fitting ? Reason for new engine just so we know the background to your situation head bolts used standard ?
 
T

Thor

Member
Yes the head an block was complete rebuild with all new parts. The bolts are standard!

Is it possible too change the HG if the engine is in the car?
 
PobodY

PobodY

Moderators
Staff member
You might get away with retorquing it now. - It's not that different from Danny's suggestion of leaving it for a day or so, then doing the final torque.

The reason I suggest that is that I doubt the metal HG has failed, so I don't think you really need to replace it.
 
K

katemc

Member
It is possible to remove the head with engine in the car , may be worth removing checking surfaces etc.

check the gasket also then re-fit as per red readings info .
 
K

katemc

Member
To be far , cosworth gaskets have a really good reputation .

it sounds more like the block or head are not flat and true .
 
red reading

red reading

Active Member
I have fitted loads of cosworth head gaskets and never had a problem, when you do it again do the torque procedure with moly grease on the threads and under the head of the bolt. And tbh to have oil on the pistons and coming out of the exhaust ports does not sound like head gasket issues as if it was that bad you would have coolent everywhere as well......sound like you have a different issue......leak down test before you strip the thing as that will tell you a whole load more..
 
T

Thor

Member
Only the head was skimmed and not the block!

That is a good question from where is the issue. The water in the radiator is ok and there is not a leak. If there is a crack in the head the coolant water must went through the block too and the radiator must lose water. And that isn´t.

The head has become complete new valve train with bronze valve guides. Is it possible that at fitting the new guides there may be a crack? But on all 4 cylinders???
 
T

Thor

Member
Yes the problem is now running! We had fit the engine and only run at idle. Then we had seen the oil under the car and at the exhaust.

There is no misfire but slight blue smoke. At the moment we have cut the exhaust under the engine because we will fit a new flexpipe. But these don´t can make a problem...

We have checked the compression if the engine was cold and there was ~ 6 bar on all cylinders.

My friend has made a tool which was had used for the leak test. At each cylinders slight air was went through the pistonrings but we don´t have found air at the valve seals, but i had heard the air on anothe cylinder! So as we put air the 2nd i heard the air on 4th cylinder!
 
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