two of the bolts on my driver side top motor mount on the bracket that go into the block are broken inside the block.


so the bracket that bolts into the block and holds the motor mount up is only held up by one bolt. is it safe to drive like that?


what should i do since i cant get the broken bolts out. its as if i have no top driver side mount.

Let me guess, you're not running torque mounts?

No, it's not safe.

Depending on what kind of damage is done to the threaded holes on the block, you may have to have the holes welded up, drilled out and retapped or you may be able to fix it with a time cert or helicoil.

 

what would be the easiest fix? i hav one bolt in there holding it up, the other one is half broken inside, and one of the actual holes that it goes into is snapped and half broken off. is there a specific size helicoil to use?

 

bolts are quite easy to drill out, you just have to have some paitence, drill bits, and a bolt extractor (can be picked up at your local hardware store for probably around 10 bucks, all a bolt extractor is, is basically a reverse threaded drill bit with a tighter spline pattern).

basically drill a pilot hole on the broken bolt with a small bit, then continuously bore the hole out with larger drill bits to allow the bolt extractor to fit with enough bite, but make sure not to exceed the diameter of the bolt threads, you can guess what happens if you do.. (retapping, finding a bolt to fit, etc... no reason to have to do that!). since there is no head on the bolt, there will be very little torque left on the bolt making it easy to extract.

once the hole is big enough for the extractor simply drill it in and the bolt will extract. then replace!.

remember to have patience as this bolt will likely be a grade 5 or higher bolt, meaning hard dense metal.

Good Luck!

 

bolts are quite easy to drill out, you just have to have some paitence, drill bits, and a bolt extractor (can be picked up at your local hardware store for probably around 10 bucks, all a bolt extractor is, is basically a reverse threaded drill bit with a tighter spline pattern).

While this is all true, the real problem he has is the lack of space to get a drill in there!

From the timing belt article.

The two broken bolts that hold the block-side of the mount sit below the lowest point of the cavity for the chassis-mount. Unless you have a compact drill with a short 90 degree bend, it looks really tough.

Yikes... I'm trying to think of an easy way to do this without having to pull the block but am coming up blank!

 

oh wow, this is a mini project, i guess im just gonna buy a drill bit and extractor and find a way to drill the bolt and extract it out, any ideas why they broke in the first place? i hav all my torque mounts in and they were all new, i do push the car a lot but still, my motor is a stock ls, its not like i hav tons of torque. maybe wrong bolt sizes were in there? or torqued in wrong? any tips or precautions i should take to not let it happen again? thanks guys, appreciate the help, im driving it to work and back but very easy, idk if this is such a good idea.

 

same thing happened to me! the previous owner didnt put grade 10 bolts in there and they snapped. luckily only one bolt broke, but the other two pulled the threads right out of the block. i used a 7/16-14 heilcoil to make new threads. and put some grade 8 bolts with a ToN of locktight. as for the lack of space, loosen the other mounts and jack the motor up sky high. wouldnt hurt to replace the timing belt and water pump while your down there!

 

Hmmm... how the bolts broke. There are a couple of possibilities.

-The prior owner used inferior quality bolts or did not torque them properly.
-The mount was not bolted all the way down the posts. This would create a stress cycle when the engine would flex, and the bolts would experience the most stress.

 

ok an update, so i got the broken bolt off using the drill and extractor, so i hav 2 bolts on the top two holes, but another problem is that the actual hole for the bottom bolt is cracked off. like the actual wall for the hole is gone, so what would be a way to solve that? welding? or can i just use the top two bolts?