Snapped Timing belt tensioner bolt into block
 

Bought the whole car for $500 with a blown HG. Was replacing the HG and the timing belt tensioner pulley bolt was stuck. It broke off in the engine block.
I'd drill it out, but I know I'll screw it up.
Anyone know a place near San Jose to get this fixed? I called a couple auto shops and they say they would screw it up too. Engine is in the back of my truck.

Re: Snapped Timing belt tensioner bolt into block
 

Any machine shop should be able to do it, removing seized bolts is fairly standard practice for them. I had the same thing happen to me with my BMW engine two weeks ago. You're smarter than me not touching it lol, I tried to extract it then failed, then had to pay the shop more because the extractor snapped off in the bolt and extractors are stupidly hard, brittle steel and virtually impossible to drill out.

Re: Snapped Timing belt tensioner bolt into block
 

Ha that's exactly why I didn't try it. :cheers:
I found a machine shop that can do it no problem. Auto shops probably just outsource this stuff to machine shops.

Re: Snapped Timing belt tensioner bolt into block
 

Most auto repair shops won't waste their time with such jobs due to inexperience or lack of proper tools. I had a similar issue before when one of the 3 motor mount holes stripped out. In my case, I had to remove the longblock and dropped it off at a local machine shop for the repair.

Re: Snapped Timing belt tensioner bolt into block
 

Ahh come on MotorMouth, you're better than that! lol, but yea I've done the exact same thing. It seems those screw extractors are prone to snapping off just because they're so freaking hard that their also brittle. Hardness ≠ strength. Good idea sending it off to a machine shop.

Re: Snapped Timing belt tensioner bolt into block
 

Yeah...I'd never really used an extractor before so I torqued it harder than I should have and it snapped. I've learned my lesson though, not touching the things again.

When looking for solutions to the broken extractor I came across some old machinist dude on youtube who put it very well: "It's half the size and twice as brittle, and you actually expect it to work???"

Re: Snapped Timing belt tensioner bolt into block
 

I've never had one work successfully. I've only broken them off and made things worse.
So this was fixed by welding on some material to the end of the stud and welding on a nut. Once the welding was complete, thermodynamics took care of the seizure. From what I understood, the different metals expanded at different rates basically stretching out the hole enough to unscrew the bolt. What's even better, it was an old HS buddy and he did it for free :)

Re: Snapped Timing belt tensioner bolt into block
 

It's hard to remove a broken bolt at that location. The shop had to drill it out, weld in the hole and re-tapped it

Re: Snapped Timing belt tensioner bolt into block
 

If a machine shop is going to do the job then they would want as much clearance to be able to work on the stuck bolt.

If there is a partial thread available
If you can find a similar bolt that will fit the broken bolt hole.
Would center punch it and drill a hole on the end (fairly deep)
This can be done on the bench and give one the best chance to get it right
Then take the bolt and cut it so that it can be screwed into the hole
Use it as a drill guide to drill a hole in the middle of the broken bolt
Then should be able to go bigger on the drill bit until you have the best chance of using an "easy out" to get the rest of the broken bolt out

If there is no available threads then best to weld a nut to the broken bolt
The heat from the welding should help loosen the bolt
And the welded nut should help turn the bolt out

Of course, it is much easier to pay a machine shop to do it ... lol

Re: Snapped Timing belt tensioner bolt into block
 

Um yeah....which is why the block has to come out of the engine...so the machine shop can work on it.

Re: Snapped Timing belt tensioner bolt into block
 

Most machine shops AREN'T MECHANICS and don't have a garage to work on your car, if it's still in the engine bay. DUUUHHH...lol

Re: Snapped Timing belt tensioner bolt into block
 

When these snap because of over torqued bolts this won't apply , but if it stuck from corrosion it will. When steel and aluminum corrode together it is basically creating a chemical reaction and the corrosion is larger than it should be. ATF will help break down the corrosion. I can't tell you if Honda atf will work. I have only seen it with regular auto store atf. If anyone has a questionable bolt give that a few days to soak and follow it with some pb blaster before trying to move it.