Attempting to change the head gasket on a W202

[a111r]

Would new manifold studs and nuts, using the 'double nut' method of insertion, make it easier?

Well done for your persistence.

 

[toolman1954]

Hi,
Thanks for the interesting update, and condolences on your family member loss.

" Unfortunately, I managed to drop a bolt (not a head bolt) into the gap between the timing chain guide and the head. I have not been able to retrieve it. "

Everything has to be somewhere.........I really would not be happy about leaving a loose bolt in an engine, especially when it might be close to a timing chain whirring around at a zillion miles an hour.
Do you possess / have you tried to use, a long flexible claw pick up tool, that might extract this wayward bolt? I have sold hundreds of these over the years. Or even a piece of welding rod with a wee bend on the end to hook it out.
Perhaps it has dropped into the sump? I assume you are putting fresh oil into the car. When you have the sump plug off, have a fish around inside with a piece of wire or a telescopic magnet, do try to locate it. Especially after all your hard work you don't want it going bang !
As above, ( per a111r ) I would use new manifold studs and nuts, especially on the inaccessible places as they will screw in by hand. Does your neighbour have any taps and dies ?? Just a cheap tap for cleaning out the threads in the head would be useful.
If you put 2 hacksaw blades in a frame (obviously side by side) and just saw a slot in the top of the stud you can use a stubby screwdriver to screw the studs in before tightening them down with 2 nuts. If you should do this, put a nut onto the stud before sawing, and then unscrewing the nut will clean up the thread. Also leaving the nut half a turn on the stud will stop the screwdriver blade slipping off when you fit it.
I hope you find the rest of the missing bolts, they will be laying about somewhere, probably wedged on a ledge while you was taking them out.
What did the machine shop at Wellingborough do to the head to sort out the porosity in the past welding?
Keep up the good work.

Steve.

 

[Nasco12]

I have done what I can to locate the bolt in the timing chain area. I even used an endoscope. No luck, which makes me think it has ended up in the sump. I quite agree that it needs to come out.

"What did the machine shop at Wellingborough do to the head to sort out the porosity in the past welding?"

More welding, apparently.

 

[Nasco12]

Final update

A neighbour (what knows about this sort of thing) suggested that I check to see if the engine cranked or not. It didn't. Or rather it did a bit and then jammed. Whether this was due to the lost bolt or not I don't know but for me it was a showstopper. According to Haynes, removing the sump is no picnic, certainly not at the side of the road. Having the car taken to a garage could lead to big bills with no guarantee of ultimate success.

Earlier today the car was taken away to the scrapyard.

 

[toolman1954]

Sad news after all that hard work you put in, and all the money you spent, but perhaps it will give someone else a project to carry on with.

Steve.

 

[grober]

That's bad luck perhaps your story will help others faced with the same predicament.