exhausts

[mighty millsy]

what is the best way to loosen sieized up bolts on the exhaust manifold .gaskets are blowing cheers

[R0B]

Lots of plusgas.(Not wd40)Applied over a couple of days.Theres a good chance one or more could snap though.Good luck

[ghost123uk]

And heat from a gas blow torch, you can get them pretty darn hot, and it really helps (along with the PlusGas), but not red hot or you risk melting the alloy they screw into

[AngeloEvs]

You may want to invest in a set of 'Bolt Out' Sockets - these grip rounded and deformed nuts/bolts far more effectively than normal Hex sockets - my local garage managed to remove some extremely worn nuts/bolts using them but some needed different techniques. Best of luck - not a task I envy!

[fairwynds]

This can be a pig of a job, and one that can eventually lead to sheared bolts and engine out to tackle the mess!
Do not try to do this job without thoroughly soaking the parts in PlusGas (/\/\/\/\ WHS re WD40). Fork out for the special 'rusty nuts tool' and use heat. In fact, use ANYTHING you can but brute force - you will shear the bolts otherwise. Also, many systems have a combination of bolts or nuts and studs, depending on the exhaust type fitted and the access against the pipe bends. Even if you have to file down a ring spanner to get access, do it. Quite a few people are eventually fitting new studs with the proper brass type exhaust nuts, and I know one company at least sells the nust which are 1mm narrow outer diameter, to allow better access (doesnt sound much, but really helps - cant recall the company at the moment, could be Brickwerks...?)
Once done, put 'replace exhaust nuts/studs/bolts on your 2-3 year service planning!
The very best of luck with this.

[AngeloEvs]

Nuts were easier to remove than bolts as different techniques can be used to remove a nut. The bolts were the problem and the last remaining one in particular. Rather than have to drop the engine if it sheared, the mechanic and I thought about the possibility of grinding/cutting the head off - open the exhaust flange hole diamter and use a sleeved M8 nut. Unfortunately, they are difficult to obtain (even though used in many product applications) but easy to fabricate or make using Standard SS nuts if you have a small engineering workshop or access to a lathe.

As it turned out, all were removed without any shearing.