Thread: Should head bolts be changed?

They should be OK to reuse unless they have corroded . It is only on some modern cars that you need to replace them as they are meant to stretch .

Inspect the threads closely and replaced them if there is any sign of damage or stretching,

Cheers Charlie

Originally Posted by 1950landy

They should be OK to reuse unless they have corroded . It is only on some modern cars that you need to replace them as they are meant to stretch .

Yes as 1950landy says, the newer cars like the Freelander etc have torque to yield (TTY) bolts and shouldn't be reused.

I'd run a die over the bolt threads and also run a tap through the threads in the block to clean them up. The torque rating is different depending on wether the threads are dry or lubricated. If you lubricate them, don't over do it as the oil isn't compressible and works like a hydraulic jack. Just a little bit on the bolt threads is enough.

Also remember to retorque after engine has been brought up to temp and then allowed to cool for the first time. Modern cars usually do not require this either.
Paul

Jeff, if your engine is original it will be a 2-litre "siamese bore", so-named because the distance between bores 2 and 3 is greater than between bores 1 and 2, and bores 3 and 4. A legacy of the fact that this engine is a development of the earlier 1600cc variant.Make sure you have a head gasket on hand before you start. These head gaskets are liable to failure between 1-2 and 3-4 if the engine is asked to work hard (high gas loads) before it is fully warmed up. Do a compression test before you dismantle and record the results for comparison with post-overhaul figures.
Second point, remember that the exhaust valves are in the block. Not difficult to remove with an ordinary valve spring compressor for either replacement or regrind/lapping in. Good luck!
Cheers Rob S