Incorrect head gasket thickness. There are a choice of 2 or 3 different thicknesses on most vauxhall diesels. If it is too thin for the amount of piston protrusion then you get piston/valve contact.
James of Sunderland
Thanks for that James. It turns out that the problem is due to a bent valve. After Vauxhall replaced the two broken followers I wasn't happy that they had got to the bottom of it so I had a close look. The problematic vale appeared slightly bent (difficult to tell with only the rocker cover off)
Removed the head and sure enough it is bent. There is a distinct mark on the top of No3 piston and very faint marks on the other 3 cyclinders. This proves that the timing was out when the belt was first changed. Jonathan-Dabbs-2004
No you don't, you just get a slightly high or low compression ratio. The gasket thickness doesn't alter things anything like enough to cause valve/piston contact of which there'll be about 1.5mm on a std engine.
Dave Baker - Puma Race Engines
All the followers should be changed. Chances are that more of them have been overstressed and are waiting to break.
Dave Baker - Puma Race Engines
Good point Dave I have noticed that there are marks from the exhaust valves to varying degrees on all 4 pistons. They are in order of worst to least 3,2,4,1.
3 Was the one with the bent valve and the broken follower. You can actually see an imprint of the machining marks on the valve imprinted in the top of the piston. I think while I have it in bits new exhaust followers may be prudent.As I am now 100% sure that the timing was out (due to the incorrect fitting of the belt) what's my best course of action for financial redress ! Jonathan-Dabbs-2004
Take photos. Maybe get an independent opinion for backup. Relate all this to the garage and see what they say. They'll probably just come and look and agree everything.
I was involved in a very similar thing as the independent expert some years back. A garage had cocked up the cam timing on a rare model of Lancia and some time later it broke down. The owner had it towed to a Lancia specialist and they came to me as an engine consultant for a diagnostic stripdown to establish the problem. The garage had used the flywheel ignition timing marks instead of the TDC marks to set the cambelts so everything was about 30 degrees out. Bent valves, broken rockers, very easy diagnosis. The garage passed it to their insurers who sent out their own expert who took about 30 seconds to agree with me and the case was settled.
If the garage refuse to compensate you, including for your labour already incurred then it's an easy small claims case.
Dave Baker - Puma Race Engines
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