Heat Shield Bolts Siezed

I need to get the exhaust heat shield off to find an oil leak. The bolts that hold it in place don't seem to take either an 11mm or a 12mm socket, so either they are 11.5 (?) or they've deteriorated. The biggest concern I have here is that I'm afraid if I get too hillbilly on these (vise grips, hammer and chisel) I may end up without a way to mount the heat shield, or worse I may damage the exhaust manifold.

Anyone else dealt with this on a Sambar? What strategies do you recommend? How do the professionals deal with this sort of thing?

 

We have to remove these things all the time to put new catalytic converters on so I know just what you're talking about. Heat them up with one of the little propane torches, smack them with a hammer, grab your vise grips and they'll spin right out, most of the time you won't even damage the bolt head

 

Thanks for the reply. I'll have a go at it later today.

Does it help or hamper if the engine is really hot? I can't imagine the little torch heating the manifold as much as driving up a good hill, but perhaps you just want to apply heat to the bolt ??

 

hindrance, because the manifold gets everything so hot you can't work on it, and using the torch gets the bolt heads MUCH hotter than they would ever get with just the engine running no matter how hard you were running it. Just get them really hot, smack them a couple times with the hammer and they'll spin right out. There are those occasions where nothing you can do will get them out other than grinding the bolt head off but most of the time you don't have to

 

You can also get a bolt remover set. The look like sockets from the outside, but instead of straight sides on the inside, they're curved and basically cut into the bolt head for grip when you untorque them.

 

Once you remove the heat shield, is it necessary to put it back on? It's actually vibrating against the new cat converter on high rpm, which is pretty annoying.

 

I took my truck in to have the heat-shield bolts replaced and to have the oil leak looked at. I wasn't expecting the shop to be able to get parts but I hoped they would at least identify the source of the leak so I can plan the job. The heat-shield bolts are changed so that's the main job. They determined that the head gasket is leaking oil (nothing else). They also took the exhaust manifold off to get a good look.

The valve cover is not leaking, the cam and distributor are not leaking, and basically everything is dry but the seam between the head and the block.

So my first thought is, what if I re-torqued the head? Can that hurt?

Also, the recommended torque is 3.0 kg.-m. or about 22ft.-lb. which isn't much. Would it really hurt to go to 28 or 30 in an effort to stop the leak?

If I have to change the head gasket, how long should the job take if done in the shop by a pro? And can it be done without removing the engine?