Went to change the spark plugs and found that one of the bolt holes for the front coil cover is severely stripped. You can push the bolt all the way in and pull it straight out without any resistance. I was thinking about using a helicoil to fix the problem, but I'm hesistant about drilling out the bolt hole bigger to install the helicoil. any other suggestions?
Stripped Bolt Hole on Engine Block
- Thread starter movado75
- Start date
Little bit longer bolt.
Helicoils work great. Timeserts are even stronger. They leave you a stronger thread than the base aluminum. Just make sure to drill straight. Aluminum is softer than it looks.
indeed and i know that magnesium is a pita metal at times so be sure to check it won't get any chemical reaction.
Now I'm even more hesistant about using a helicoil. I'll check to see if the existing thread goes deeper for a longer bolt. I was thinking about just re-tapping the bolt hole and putting a in a slighter larger diameter bolt. But, I'm not a big fan of that procedure.
Helicoil is principal not that much different, since you tap up to a large size then insert the helicoil to bring the size back to the correct one.
I'd like to know the exact composition of the magnesium since machining it can be very dangerous (fire and a nasty one at that)
Putting a Helicoil in the valve cover is not a problem (this is a M6x1.0). However, I would recommend removing it from the engine. If you're not familiar or don't have the tools to properly drill and tap - an engine machine shop can easily do this work for you. It shouldn't cost more than $40-50.00 to do the work.
A customer's car we are working on this week has 43 thread repairs required! Whoever did the engine service last time replaced half the bolts with inch bolts in metric threads!
-- Chris
A customer's car we are working on this week has 43 thread repairs required! Whoever did the engine service last time replaced half the bolts with inch bolts in metric threads!
-- Chris
Indeed taking it off and having a machine shop do it would be best.
That is just so wrong on so many basic levels. It's getting hard to let anyone do anything to anything you own nowdays.
Machine shop is probably the way to go. Chris, are you using helicoils to repair all those threads?
Someone stripped a thread in one of the magnesium valve covers of my NSX years ago and it was fixed with a Helicoil. After the coil covers were taken off and put back on enough times when changing the spark plugs, the Helicoil came out of the valve cover.
After that, I took the valve cover off the engine and had a machine shop install a Time-Sert. The guy on the drill press cursed the hardness and brittleness of the magnesium but I hope this repair will now last forever.
After that, I took the valve cover off the engine and had a machine shop install a Time-Sert. The guy on the drill press cursed the hardness and brittleness of the magnesium but I hope this repair will now last forever.
Yes. Helicoils work great. Timeserts also work but require more working room with the part ideally out of the car - which makes them difficult for certain many chassis repairs.
-- Chris
I was under the impression that it was Helicoils that are stronger than timeserts.
At least my friend that works at a military base only uses Helicoils on their Apaches.
