Broken engine mount bolt Mk6 GTI

[Jaffs]

I have a Mk 6 GTI with 150K on the clock. I maintain it pretty well and am aware of the usual things. You know, a coil on plug sh*ts itself so I replace all four, because the drive home was so heinous I never want to experience that again. All has been good and I just serviced the thing (I do it myself).

Well bugger me, I took off from a standing start from the side of the road under really moderate load and snapped an engine mount bolt on the right hand side (mount to engine bracket M12 bolt). Lucky I wasn’t far from home and I risked it driving with only one bolt of unknown reliability - not that I knew what I was facing at the time - I assumed it was a K frame bolt. I heard a noise and turned around to retrieve a snapped bolt from the middle of the road. Catastrophe averted, but only by luck really. I’ve replaced the mount and all 6 bolts and will now do the transaxle mount and bolts as well. What surprises me is that I’ve had work done (timing chain, DSG clutches, flywheel, rear main seal) at a workshop that specialises in German vehicles and they didn’t replace a single bolt that is torque to yield (e.g., engine and transaxle mount bolts, K frame) whereas the VW dealer said they definitely should be replaced.

I chatted to the person where I had the work done and he said they always reuse bolts like that, but won’t do the usual torque spec + 90 degrees as recommended with new bolts. They've never had a broken bolt like that, apparently, whereas the VW dealer says it happens all the time. German specialist workshop said it’s usually the transaxle mount that goes whereas VW dealer said it’s right hand engine mount (like what I replaced). FFS, surely there is some commonality in what is seen with mount failure and snapped bolts. Anyway, now I am going to replace the left hand mount and bolts as well, and maybe dog bone mount.

Questions. Has anyone snapped an engine mount bolt? Is the right side engine mount usually more knackered than the left side transaxle mount? Should I do an insert in the dog bone mount and be done with it rather than spending about $450 to do bushes properly by dropping K frame (at German specialist garage)?

Advice. Clean your threads. The bolts should go all the way in by hand initially (well, to a good extent, perhaps with a little light socket action). The specialist workshop seemed not to do this. The snapped bolt came out easily, thank fark, but the other M12 was creaky as hell as I removed it. I used some good penetrant spray on it and worked it in and out to carefully get it out. Then I used some ATF fluid and the unsnapped bolt to carefully clean out the thread in the engine bracket (the one that has to come off to do a timing chain…). Finished with brake clean and compressed air to blow out the hole. I didn’t want the grief of having to replace that bracket, or to drill, tap, and use an insert/helicoil, and I think I’m lucky I saved it (did 60 Nm + 70 degrees and left it at that). Isn’t cleaning threads a common thing a workshop would do? Incredible the difference it made, and especially so when trying to get a proper torque reading. Good mechanics would surely know the importance of this. I saved my bracket by cleaning out the thread and it was galled a fair bit after the snapped bolt affair.

One more thing. Why wouldn’t a workshop recommend a dog bone mount replacement while the K frame is dropped on a car with 140K km for a job that is already costing about $4500? I’d rather have the option of spending a few $100 more to have the peace of mind, but I didn’t think of it and it wasn’t offered (same applies for an old arse transaxle mount - should have an option to replace it when other work is being done, like my clutches).

Shout out to HSY Autoparts. Half the price of the dealer for most parts. Had to go to the dealer for the bolts though. For everything else, it’s HSY (or Bursons for coils if necessary ��).

I’ve written a veritable essay but I hope it helps others if they come across this scenario.