Exhaust manifold bolts

[Wes©]

Had a 2001 TD5 Discovery today with 3 sheared manifold bolts. Is this normal?? its the second TD5 that I have done in 4 weeks with the same problem.

The Discovery that I did today was also "chipped" with 168 BHP, could that have anything to do with it? It went well though :lol:  190 KMH on the autobahn here in Germany

[muddyweb]

Don't know about 'normal'.  Mine never did it :-)

I would think that the only way the chip could affect it would be by increasing the vibration / torque-over of the engine, but it's a very tenuous link.

[Moose]

Ah, someting I know about ( re my web creation failure)

I will check this out tomorrow, however it has been known for bolts that have  not been de-embrittled correctly to shear. - and you can't see the problem ( during curing of corrosin coatings on hard fasteners, you can get hydrogen embrittlement, these are reheated and cooled correctly, ths returns then to the correct state.)

It is probable that one of the (my) groups companies coat these bolts could you tell me if they are all from the same year ?

[Wes©]

The defender with the sheared studs was a Tomb Raider 90 I think it was 2001 and the Discovery was also a 2001. Not 100% sure though, if it is important i will look it up tomorrow .

Wes