Thread: 300Tdi - Broken housing after Timing belt changed - How serious? What to do?

LOL! silicon.
is is silicon squidgy, or is it rock hard like JBWeld?

Either way, I don't think it'll be a problem.

Thanks for your thoughts Arthur.
It's a soft silicone, so cosmetic only.

My concern is that it has been drilled out (rather than putting an insert in) and so weakening the whole structure. Then sometime in the future, corrugations will cause the housing to crack.

Cheers, Nigel

It's also the wrong bolt. Seems like a bit of a bodge repair, but as long as the other bolts are firm I probably wouldn't worry unduly. But, if you are concerned, and the mechanic did this, then take it back. That rear housing ain't cheap.

I would say some previous 'repairer' may have tried to use one of the longer(50mm) bolts, where that part takes a 35mm long bolt.
The backside is blind, not open, and the 50mm bolt broke through.
Probably ruined the threads too, and could be why that bolt is the odd man out(is it the same thread size?)

There are about 5 bolt lengths for the cover from 25mm to 110mm in length, most are 35mm tho and the diagram of where each one goes in in the engine repair section of RAVE.

When doing a cover removal-refit, eg. when doing the timing belt, I use the gasket as a template overlaid on cardboard to store the spot for each bolt as it's removed.

I don't reckon corrugations will cause the rear housing to cause any cracking. The injector pump should have a strong mounting bracket from block to pump, and the pump itself should act as a secure bracing for the rear section of the housing.
In fact, I think if anything would cause cracking it'll be the vibration of the tdi at idle, more so than corrugations anyhow. But even the vibration shouldn't cause any issue for this area.

re the replacement bolt, you will find the thread has not changed, the original bolt has a head that is (what?) 10mm, its difficult to find that metric thread size with the small head.
the replacement bolt will have a head that is 12mm.

If it's holding torque I wouldn't worry, I'd be more concerned about the split bleeder hose.

Originally Posted by discorevy

If it's holding torque I wouldn't worry, I'd be more concerned about the split bleeder hose.

Thanks ChatterBox, I noticed the hoses when I was posting the photos; definitely time for replacement.

Cheers, Nigel

I agree with Arthur at post #5, a too long bolt has blown out the blind threads and the guilty party has tried to seal the end with soft silicon to stop corrosion. One less bolt won't matter unless it is stripped and spinning, hopefully it is not just being held in there by the silicon.