mrboomberang Posted March 12, 2018 Share Posted March 12, 2018 Has anyone broke the bolt that holds number two coil pack in place any help appreciated tried drilling it out but no good ? Missfires when hot Quote Link to comment Share on other sites More sharing options...
Mk4Gaz Posted March 12, 2018 Share Posted March 12, 2018 If the bolt has sheared off flush with the head, the best advice I can give you, is to use a cobalt drill bit, and drill very slowly into the remainder of the bolt centre. Then use an 'easy out' to remove it. Soak it in a penetrating oil a few hours before you try, and keep any swarf out of the spark plug wells Quote Link to comment Share on other sites More sharing options...
evinX Posted March 12, 2018 Share Posted March 12, 2018 Drill tap and die. One of the easiest and most useful skills for a 20yr old car owner to have. Plenty vids on youtube Quote Link to comment Share on other sites More sharing options...
rider Posted March 12, 2018 Share Posted March 12, 2018 (edited) I had to extract quite a few bolts in my recent sub frame swap where the bolt heads were so corroded they rounded or turned off altogether. I used a couple of techniques to tackle them successfully with drilling and tapping or using a stud extractor. Drilling out is going to be difficult on a stranded stud from a small size bolt in the centre of the engine bay as the chances you'll be reaching over and drilling straight and true is not that great. If you end up drilling at an angle you could end up with an oval hole with part of the seating thread drilled away and no way to cut a new one. If you do go drilling use the left hand reverse drill carbide bits on a hammer setting which will have a chance of catching and unscrewing the stud. Bad news is the Supra bolts seem to use tough steel and they don't drill easily even with new quality drill bits. I've never been that lucky to have a left hand bit bite though and had to completely drill out. If the worse comes to the worse and you do damage the seating then you can recover the situation by drilling a larger hole and use a helicoil insert to restore the thread. I'd probably want the head on a bench though to ensure a perfectly vertical hole is drilled. If you have lost the bolt head then presumably you can remove the coil packs and cradle to clear access to the damaged bolt stud and if there is any protruding you have options available. If you can grind flats into the bolt stud then you can use a small adjustable or standard spanner. If you can weld globs of metal onto the top of the bolt stud then you use a stud extractor. I prefer doing this to drilling. If you do end up drilling then put some cotton wool down into the plug area to catch any swarf as you won't be able to vac it out afterwards. So you'll need a hammer drill, 6mm left carbide drill bit, mig welder, 6-12mm stud extractor and a steady hand to have all options. Edited March 12, 2018 by rider (see edit history) Quote Link to comment Share on other sites More sharing options...
jonc Posted March 12, 2018 Share Posted March 12, 2018 All the above with a couple of tips. The bolt is only a normal grade M6 bolt so should not need any specialist drills (HSS or Cobalt). Centre pop the centre of the broken bolt and start using a small bit 2.5-3mm. Then step up maybe to 4mm and drill again. Two options after this/ Either use an easy out to pull out the remaining metal OR drill out to 5mm and re tap. The only difficulty is a steel bolt into an aluminium casting so be accurate with the first drill and hence centre pop. Tap should be M6x1. These cars will have plenty of issues like this now so these skills are good to have. Use lubricant when drilling and maybe penetrating oil before you start. Quote Link to comment Share on other sites More sharing options...
Dnk Posted March 13, 2018 Share Posted March 13, 2018 (edited) Has anyone broke the bolt that holds number two coil pack in place any help appreciated tried drilling it out but no good ? Missfires when hot /QUOTE] You say you've had a go at drilling it so what state is the bolt in now ? can you take a photo You're talking about the bolt that holds the coilpack bracket to the cylinder head ? If its the bolt into the cylinder head you could make a plate to bridge the gap to the next bracket and use that to clamp the other in place You could also use this method and use the bracket as a drill guide but you'd need to be careful and use as light a drill as possible, using the bracket would help you keep the drill square to the head and in the centre of the broken bolt Edited March 13, 2018 by Dnk (see edit history) Quote Link to comment Share on other sites More sharing options...
mrboomberang Posted March 27, 2018 Author Share Posted March 27, 2018 Has anyone broke the bolt that holds number two coil pack in place any help appreciated tried drilling it out but no good ? Missfires when hot /QUOTE] You say you've had a go at drilling it so what state is the bolt in now ? can you take a photo You're talking about the bolt that holds the coilpack bracket to the cylinder head ? If its the bolt into the cylinder head you could make a plate to bridge the gap to the next bracket and use that to clamp the other in place You could also use this method and use the bracket as a drill guide but you'd need to be careful and use as light a drill as possible, using the bracket would help you keep the drill square to the head and in the centre of the broken boltThat's what I'm planning on doing mate cheers Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.