Seized exhaust bolts

petebates26

Hi all,

I'm trying to change the centre section of exhaust, but I'm having serious bother getting the bolts out of the front, where it's attatched to the manifold. It's a 1.6 8V Z16SE engine.

I've soaked it in WD40, but I'm not convinced this is getting into the threads as I'm applying it from underneath.

I've tried Halfords Shock and unlock spray (Cheap version of plusgas - I had a voucher!)

I've just bought a blowtorch - I've tried heating the area, but still no joy!

Does anyone have any tips or any other methods that I could try? I'm just heating the general area - mainly the bolt. Should I be heating the manifold only? And should I allow it to cool before trying to loosen them, or even cooling it rapidly with water?

Thanks all!

Igol

Depending how bad things get (personal experience suggests that it goes downhill rapidly). Drown them in penitrating fluid and keep drenching them, blow torch on the bolt head and a big breaker bar on the wrench. Hit them while they're hot more oil if necessary and repeat - enjoying the small fires clouds of smoke.

If that doesnt work, and they havent rounded off yet bead of weld on the head of the bolt can break them free or gas axe to heat them up til red hot (coz we all have one of them tucked away).

When the heads round off Irwin bolt removing set - dont scrimp and get a silverline one they are pants and you wont get anywhere.

For the 2 that will snap off, your looking at either welding a nut onto the stub - if there is one, or drilling out.
Dont bother with easy-outs they are even worse than the silverline bolt removers and when they snap you wont drill them out.
A selection of cobolt drills in 5 mil increments, tapping fluid, taps and a new set of bolts.
You tube is also pretty good, for ideas.
You will also need lots of handy swearwords to use when things give suddenly and you introduce your knuckles to various sharp hard metal objects.
Oh and the Haynes book of lies - simply remove the retaining bolts my ar**, mainly to throw the bl**** thing at other objects that cause frustration nearby.

petebates26

Cheers Igol -i'll keep on keeping on with the oil and heat!

The Haynes manual does seem to undersell it a bit!

I've already skinned a few knuckles and educated the local kids! Looking forward to the little fires!

Igol

Good luck.
If you can get any movement at all, a mil, it should unscrew though it takes hours.
Drilling out is last resort and when you need to be very, very careful and try sticking the new bolts in copper ease before you put them back on - may make it easier next time.

petebates26

Next time? Pffft. If I get it fixed this time, I'm only going to drive it far enough away from the house so I can set it on fire.

paddedjohn

If its bolts that you are trying to undo then you should be heating the manifold not the bolt, if it nuts then heat the nuts, you may have to get them glowing to have any effect.

Keith

I'd get some Plus Gas and soak them for a number of days then try. Much easier, and a far better product than WD40

petebates26

Thanks paddedjohn - I'll give that a try. And I've been told that rapid heating and cooling of the area as a whole (with a torch then water / Ice) will help to shatter the rust - anything in that?

Cheers Keith - I'll give it a try. The Halfords Shock and unlock spray claims tht it freezes the area to contract the bolt as well as lubricating - but so far it hasn't done the trick!

KillerWatt

petebates26 wrote: »

Thanks paddedjohn - I'll give that a try. And I've been told that rapid heating and cooling of the area as a whole (with a torch then water / Ice) will help to shatter the rust - anything in that?

Don't be surprised if the manifold cracks.
If anything, heat the nut cherry red then spin it off with an air tool.

Strider590

All of the above + hope your not trying to do it with an adjustable.

epninety

Igols post pretty much covered everything, only [STRIKE]two[/STRIKE] three more things I can think of...

1) Don't be afraid of fractionally tightening the bolt/nut - sometimes the extra little movement is enough to tip the balance.
2) *Sometimes* it's easier to shear a bolt or two, remove the obstruction, and then deal with the broken bolt. This is a judgement call - sometimes you can only get an open ended spanner in there with the pipe fitted, but you know you'll be able to weld on a nut and use a six sided socket with the pipe out of the way.
3) If you do end up drilling out bolts or studs, get some left handed drills - often the heat and vibration of drilling , combined with the relaxation from drilling out the centre makes the bolt unscrew on the end of the bit. They don't have to be Dormer quality,in fact given that they'll probably be abused repeatedly over the years, they probably shouldn't be.