Maxx Mazda

I'm trying to take my exhaust heat shield off the car, but I ended up rounding off 2 of the 10mm bolts. Now a ratchet wont grab them, and even a wrench has difficulty not slipping. What can I do to get them off so that they're re-useable when I'm done?

I could just buy new bolts, but that doesn't solve the problem of how to get the original ones out...

arapau

Try heating bolt with torch and using a 6 point socket. If socket won't grip try good pair of vise-grips. If that fails you might consider leaving shround in

carguycw

Try an impact driver. If that doesn't work, cut off the bolt head using a Dremel tool with a fiber-reinforced cutoff wheel, remove the heat shield, then try and extract the remainder of the bolt with an EZ-Out. However, if the bolt can't be loosened with a ratchet, an EZ-Out may just break off, in which case you're really screwed because they're super-hard and can't be drilled out. If this is the case, I would file the remainder of the bolt down flush with the surface beneath it, then drill it out, tap the hole and install a stud and nut (not a bolt) with ample amounts of anti-seize.

BTW forget about reusing the bolts. IMHO damaged fasteners should NEVER be reused, only replaced. Reusing a damaged bolt will just cause more problems later.

Arkos

You might also try cutting a slot in the top of it and using a screwdriver.

Kopp0041

buy new bolts and go for the high speed drill, and drill those suckers out. I had to do this on the originla sway bar. They must have used some really soft nuts.

stormtown

Forget reusing the bolts. Get vise grips and twist out after liberally spraying with liquid wrench or other rust remover.

Sir Nuke

First off I would ask WHICH heat shield you are refering too....

for as I remember the one UNDER the car for the resonator near the shifter....the BOLTS are only screws that go up into the sheet metal...

if you are talking about the heat shield over the exhaust manifold...well that is another story all together..and I would be very careful and use whatever means to back them out, vicegrips, whatever...as if you break them off....then you are going to have a hard time getting them out...and drilling out a steel stud/bolt from an aluminum head is NOT fun...nor is it easy.

kc5zom

How did you strip them to begin with? Cutting a slot in the top will probably be pointless, the material won't hold up to it. Try vice grips first and then go for a drill (agree with Nuke here, this will not be fun). You might also try reshaping the top and making a smaller socket fit (sometimes works) but you will have to take off quite a bit of material to try this (get out a metal file). Forget about reusing it. Never reuse a damaged bolt.

Maxx Mazda

Yes, I was refferring tothe heat shield on top of the manifold, and I won't reuse the bolts. I'll try some WD-40 and vice grips and see how far that gets me.

If I drive around gently with the shield removed for like a day, and I going to melt my fans?

Mxyzptlk

I would try the vise grip. I had the same problem with the heat shield bolts near the oil pan. They were rusted out and stripped. Vise worked fine.

kc5zom

I wouldn't worry about it too much. Just get that thing back on there fairly quickly. I haven't looked, there aren't any wires running real close to the shield or anything are there? I would be more worried about those than the fan.

You might go to the auto store and get some higher grade penetrating oil, and wait for the motor to get cold before you mess with it again.

Kopp0041

Liquid wrench!

Maxx Mazda

Ok, so I just tried with the vice grips, and the heads on 2 of the bolts are now almost totally round. I looked in the shop manual, and found out that the bolts are put on with 70-100 ft. lbs. of torque!

I'll try again with some penetrating oil, and maybe I'll let the engine cool for a while longer. I left it cool for about an hour, thinking that if it's still a little warm the bolts may come out easier. I'll try again, but if not I'll have to drill them out I suppose. I'm heading tothe dealer shortly to get some new bolts, but in the meantime anyone got any other ideas? I don't care, just throw them out there. I just need to get this damn thing off!

kansei

I would say 70 -100 inch pounds sounds more like it . Try having the manifold hot (gloves would be good) and TAP the top of the bolts with a hammer first then vise grip this usually works

slenser

Listen to Protegé Menacé!

Obviously, you aren't putting that vise grip on tight enough if you're still rounding it off. You need to put that thing on there so tight, it takes damn near all your strength to close it! You won't be rounding it off then!