Technical Re-torqueing cylinder head - 1.8 16V ELX

Currently reading:
Technical Re-torqueing cylinder head - 1.8 16V ELX

Joseph Buttigieg

New member
Joined
Jan 1, 2012
Messages
66
Points
23
My Marea 1.8 16v has developed an external oil leakage, which appears to come from the head gasket right at the corner next to no. 4 cylinder exhaust manifold.

After a thorough investigation, it appears that the leakage has developed at the cylinder head gasket.

Before deciding to pull of the head, I am thinking about a last resort: re-torqueing the cylinder head.

This seems to have worked on other cars in some cases. Some manufacturers even recommend it for some engine types. Anyone tried this before?

Problem is that the bolts are stretch bolts meaning that they should only be used once. The tightening sequence is 20 Nm+40Nm+90 degrees+90 degrees+90 degrees. Actually they shouldn't go loose as the bolts have been stretched into their plastic range.

This procedure does not indicate a final torque level which I can check.

My head gasket has been renewed 100.000 kms (7 years) ago. I'm not quite sure whether the garage doing this job renewed the bolts at that time. Some manufacturers recommend renewing the bolts after lets say three times retorquing but the Fiat manual is silent on this. Perhaps the bolt next to the leak did go loose or the gasket has lost its resilience. Could be a slight warp in the head of course.

For the rest, there are no internal leakages so this oil sweating is the only issue at this stage.

The leakage is next to no.4 exhaust manifold ie. at the right bottom corner in the pic below. As you can see in there is a bolt adjacent to the oil galley from which the oil is leaking.

Any advices will be highly appreciated.

I need advice.
 

Attachments

  • IMG_NEW.pdf
    447.5 KB · Views: 52
Last edited:
I cannot see that removing a single bolt in that position could cause problems so I would buy a single new bolt and replace it. The possibility of resolving your problem without removing the head makes it worth a go in my opinion. By using a new bolt you don't have to worry about whether it has been reused or torqued correctly.
Good luck:)
 
Peter,

Thanks for your response.

I don't really think that's a good idea. If the other bolts have been torqued to a value lower than that recommended by the factory and I torque this one to factory value, then I can end up warping the head.

Whatever the solution might be, I think that all bolts will finally have to be torqued to one common value to keep the head flat.
 
I understand what you are saying but the only other solution is to do the job correctly and have the head off. If you do that you will be having the head checked and probably skimmed anyway so you have nothing to lose.
The problem always with trying shortcuts or 'imaginative engineering' is the 'what if'.

I think my idea is worth a try for the cost of one bolt but if you are at all unhappy about doing it you shouldn't.

Good luck with whichever route you go down :)
 
Back
Top