Thread: bloody 4.6's

Blown head gasket +/- warped head

Originally Posted by Lotz-A-Landies

Blown head gasket +/- warped head

hope so, heads were supposed to be plained with the metal gaskets 12 mths ago

I had a new short engine [3.9] fitted to my Rangie Classic after a major overheating incident which caused the head gaskets to fail and warped the heads

In the rebuild Elring gaskets were used and heads were checked, planed and reco'd.

40,000 kms later I had a leaking head gasket on one bank with a washed pot. The only sympton was a bit of very mild miss at times and the occaisonal, intermittent smell of burning coolant [the green stuff]. Apart from this the car ran like a new one and this went on for ages. It eventually failed big time and refused to run without missing.

In retrospect I think I would have kept my old engine block and had it rebuilt too. That is after pressure testing it of course.

Your 4.6 may be just like mine - a one-off failure without reason. Perhaps everything was done correctly by the previous owner and you are just like me - unlucky.

G`day , i`d suggest you give it a compression test , when it`s hot and again when cold .

When cold you are also looking for liquid .

Cylinders 1 and 7 have a liquid source from a gasket problem but 3 and 5 don`t .

Being tin gaskets i`d guess 7 maybe the gasket but 3 and 5 will have trouble getting liquid from a faulty gasket or head because of the design but ...
If the heads have been modified , as in bits ground off to open ports ETC and done badly they can fail but untouched factory heads are very robust .

well the heads are off,

the tin gasket on the offending side shows water marks running from the rear water jacket into cylinder 7 & across to 5 and then slightly to 3.

Cylinder 3 was the best of the crook cylinders.

I think & hoping the cause of this is heli-coils fitted in the block, with head bolts used,

Im fitting a new tin gasket & using studs & nuts so i can get the correct head tension!

No liner movement either so fingers crossed

too late for pics?

Im fitting a new tin gasket & using studs & nuts so i can get the correct head tension

IMHO if it has Helicoils fitted you should have the block refaced.

I would take 30thou off the heads and use composites in your position, as they are more tolerant than tin gaskets. BUT not Elring as they leaked on my block. The TRS composites are holding so far on my engine at about 12KK.
Regard sPhilip A

If you get the block refaced, make sure the engine no. is (expertly) stamped back onto the block. Trying to do it later is much harder.