Just started the fun process of replacing the head gasket on my TE and it seems that whatever moron did the head the last time stripped the head on one of the bolts while installing it. I was able to barely break the bolt loose before the threads were completely ruined, but now I am unable to get it out any further than that.

If anyone has run into this issue before or has any ideas for getting it out the rest of the way, please let me know. I'd like to avoid having to drill it if at all possible.

Thanks!

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1995 E300 Diesel - 298k
1983 240D - ~500k
2015 Porsche Cayenne Diesel - 90k
2013 Audi allroad - 153k

Drill a small drill bit in and grab on with channel locks. Lift up while spinning with a wrench.

Once it's up a little slide a big flathead under it and pry up while spinning with an impact.

If that works buy a lotto ticket.

If the head is rounded, get one of the ez-out sockets from Craftsman. They are hard steel with spirals that bite in as you turn.

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Prost!

Well unfortunately it looks like I'm going to have to drill it out, I tried using some ez-out sockets and some other types of extractors etc. and it still seems to be torqued down pretty tightly so none of those tools were particularly effective.

I've been working on taking the whole front end of the engine apart today because I noticed a crack in one of the chain guides...

Needless to say my intended quick head gasket change has turned into quite a project. Oh well.

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1995 E300 Diesel - 298k
1983 240D - ~500k
2015 Porsche Cayenne Diesel - 90k
2013 Audi allroad - 153k

Mind as well have it resurfaced, if needed. If the previous wrencher was under qualified who knows where it's at.

I know the machine shop I went to does a magnaflux, cleaning, and surface check for free.

Just checking => If you have loosened all of the other head bolts and you are now trying to tackle the last one then you have not been doing this the correct way - there is an order for the release and fitting of the head bolts. You might find that with the other bolts fitted the bolt with the broken fastener top will be easier to remove.

If you have indeed removed all but one of the bolts then you need to get the head checked for flatness before you refit - it could be warped - evenly applied force is required when fitting and when removing.

If you are still struggling with one buggered fastener top some people have reported that sacrificing a tool and welding it in the head of the bolt is a solution - cover up that aluminium alloy head really well though (and remove camshaft and rockers etc)

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1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

Good point. And even if you didn't, someone else could have.

I usually weld a nut on. Down through the threads and just melt it. If no welder, a two part epoxy putty and cure overnight.

On another note, with the old toyotas they sometimes just stick two head gaskets on. Lol. Lasts longer if it's warped.

The information is a bit confusing in this thread - I don't think the threads on the bolt have actually been damaged (as stated) - I think (from the other information) that the 12 point arrangement in the top of the bolt has been buggered. In that situation there's probably no ways other than drilling or welding.

I made a tucking fork (for bending sheet metal) out of some old head bolts and the metal is surprisingly hard (where I'd expect a fair amount of ductility) so drilling could be a real pain in the arse and the likelihood of damaging the soft alloy head goes up a notch or two...

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1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

Yeah that was my take also, after the second post. It can be overwhelming when that happens. I was taking one off and saw 3 big plug style Allan heads. Searched for the right socket for 3 days to discover they weren't bolts. I missed two down in the timing chain assembly. Now that head is getting plained as I didn't follow the sequence right.

Heat from the weld should probably be cautious too. I know I've attempted to dissipate the heat elsewhere in those situations. wrapping a piece of copper around the head. Sliding some aluminum flat stock against it. Etc.

It was indeed the 12 point triple square part on the top of the bolt that is stripped.

I did follow the correct loosening sequence and stopped when I got to the bolt that was damaged. I will probably still have the head checked before I put everything back together.

I did manage to get it loose by drilling with a cobalt bit I picked up at Sears. I believe it was a 7/16" size and it fits perfectly into the holes on the head, so there was not any contact between it and the cylinder head. I drilled at a fairly slow speed and kept the bit lubricated as I drilled and it worked like a charm.
Once I drilled deep enough I stuck a screwdriver into the hole I drilled in the bolt and snapped the head right off of the bolt.

Somewhat of a tedious process to get it out, but the head is off now, so I'm happy..

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1995 E300 Diesel - 298k
1983 240D - ~500k
2015 Porsche Cayenne Diesel - 90k
2013 Audi allroad - 153k

Congrats. Thanks for letting us know, it's always suspenseful when an episode ends with a cliff hanger.

Good work and happy holidays.