exhaust studs seized

[123-jn]

I took my exhaust off cylinders 1 and 3 today together with the knuckle and the intermediate pipe. I had one snapped off stud on cylinder 3. Guess what I now have 2 snapped off studs on cylinder 3 and one on cylinder 1. Oh Joy!!! 6-8mm sticking out so I threaded nuts on them soaked them in penetrating oil and then welded the nuts on. Unfortunately my MIG doesn't seem to be able to get enough heat into them. Anyway still no movement in the studs anyone would think they were glued in!!
Next plan is to continue soaking them in oil for a week and try welding nuts on them again with an arc welder. I really don't fancy drilling them out. Has anyone got a tried and tested method for this that works?

[kevtherev]

drilling them out

[pionte]

I had to drill out 4 of mine.... oh how I laughed another 2 needed helicoiling , oh but 2 where ok good luck, this is not a fun job... take your time and get someone to bring lots of tea and biscuits....

[123-jn]

Thanks chaps, I thought you might say that. I'll give it one last go welding nuts onto them then try the drill. I have never ended up helicoiling so not sure how easy or not that is. I have heard horror stories about them not staying put?

[kevtherev]

VW Made your engine so it can be dropped very easily in a few hours.
It makes the drilling very precise
Take a look on u tube for some handy tips.

[what2do]

Welding on nuts never fails. Slip a larrger nut than is actually required over the broken stud. This then allows you to overfill with weld, thus, absorbing more heat. Remember, it's the heat that frees off the corrosion, not the force applied by turning the nut. Weld then leave 30 seconds and they 'ought' to be super loose to undo. Fingers crossed.

No harm to children, animals or internal threads will occur through the use of this method!!!!

[123-jn]

well unfortunately the welding on nuts method failed for hours!!! So I used a flexible drill shaft and even if I say so my self, drilled the studs brilliantly centrally, so much so that on drilling with a 5.5 mm drill was left with a lovely coil of thread in each hole. Now you would think that would be easily removed. (NOT SO) It was as if it was glued in place so I lost patience and drilled it all out with a 8.3mm drill and helicoiled them. Thank goodness for that. But what a faf. Undoing the inner cv's and tying them out of the way makes it easier!!!