seized cylinder head bolts

sc4rf4ce

over the weekend ive been working on my head gasket.
when i finally got everything removed apart from the cylinder bolts it appeared they have seized. i made sure to attempt to open them in the correct order, but the first one just wont budge. Ive damaged a few wreches at this stage.
has this happened to anyone before, and if so how did you overcome this problem?
btw the car is a fiat punto mk1. so that would explain the nightmare.

Pete67

Use a good quality impact socket or torx bit (whatever fits the head of the bolt) and plenty of leverage. It should move. If it's a 1/2 inch drive socket, you can get a 2 ft long bar to fit it which will give much more leverage than a ratchet handle will. All else failing, an air wrench with aforementioned impact socket will move it. It's a good idea to replace the bolts with new ones when you are rebuilding it.

sc4rf4ce

cheers for the help. i was gonna buy an impact wrench at the weekend to remove the crankshaft drive pulley.
hopefully ill get the head sorted this weekend so.

Mr.Diagnostic

Dont use an impact gun on it. It is likely to cause damage to the bolt/torx. If you use a big bar to extend a 1/2in ratchet handle you are likely to break the ratchet.
Make sure you use a socket/bit that fits correctly, clean out torx if fitted to ensure the bit seats in all the way and use a long breaker bar (1/2in).

sc4rf4ce

the bolts appear seized to the point where the socket itself has cracked whilst applying torque.
if i use an impact socket should i get a result, or will that crack or shatter aswell?

Andrewf20

Try heating the casing around it with a portable gas gun. (Should be able to get them in any Woodies, Atlantic etc). I did this for my seized diff drain and fill nuts. The heated areas expand marginally, so it should do the trick. Another technique I read about and used was to bang the bolts tighter once then bang them open. This actually worked strangely.

Try not to set the place on fire.

(CH3)2CHOH

Righty Tighty.

Lefty Loosy.

sc4rf4ce

is that not extremely dangerous considering its the cylinder head with all the oil in the cam casing, and the proximity to the inlet manifold.
plus wouldnt using a gas gun warp the cylinder head itself.

DublinDilbert

sc4rf4ce wrote: »

the bolts appear seized to the point where the socket itself has cracked whilst applying torque.
if i use an impact socket should i get a result, or will that crack or shatter aswell?

You'll find it very hard to damage an impact socket, as they generally have a very tick side wall.. Also an impact socket will grip on the 6 flats as opposed to the 6 corners of the bolt, so should be less likely to round the corners..

What sort of socket did you break?? what size? what make?

Rovi

sc4rf4ce wrote: »

the bolts appear seized to the point where the socket itself has cracked whilst applying torque.
if i use an impact socket should i get a result, or will that crack or shatter aswell?

Impact sockets are usually made of softer material than hand sockets, as they have to absorb much more shock loading than hand sockets would normally encounter. Their thickness is the trade off between strength vs. hardness.
Hand sockets are usually much thinner and can be made of harder material to provide strength; that's why they're dangerous to use on air guns, the shock impacts can shatter them.
A good quality six point flank/shoulder drive socket (one that engages on the flats of the bolt head rather then on the corners, either impact or conventional) on a decent length breaker bar (minimum 24", preferably more) should either break the bolt free or wring it off.
The impact action of an air gun may well shock free a stubborn bolt that might otherwise wring off with a slow steady pull with a long breaker bar.

This is why professional mechanics spend what appears to be ludicrous money on top quality tools.

sc4rf4ce

well thanks for all the help guys. i used a high torque socket with an impact extension and some trusty penetrating fluid.
i removed all of the bolts bar the last two. when i got to the second last one, i noticed it was rounded.
obviously whoever fit the head gasket last time, didnt do a very good job.
so im looking at a weld job to remove the rounded bolt im presuming?
or is there an easier way to get around this?

macroman

The retaining bolts on Fiat Punto cylinder heads are stretch bolts which must be discarded and new ones fitted on refitting of the head.

Plug

macroman wrote: »

The retaining bolts on Fiat Punto cylinder heads are stretch bolts which must be discarded and new ones fitted on refitting of the head.

Most people insist you change the cylinder bolts anyway.

OP try using a long 3 foot power bar and get a very good quality torex bit like snap on or something.

MercMad

Use a socket that grips the flats of the bolt, use PlusGas penetrating fluid, its aircraft spec and never fails. I would try tapping the head of the bolt a few times with a hammer, a few firm blows, not enough to mark the bolt, but enough to break its seal. the mixture of oil and coolant has probably corroded the threads. Also you will need a long bar but try tightening the bolt a smidgen first before loosening it. If it moves at all just repeat the clock/anti-clock motion, extending it every time and when you have loosened it enough to ghet more PlusGas down, do so and let it soak for a few hours.

The last thing you really want is to shear the bolt end in the block.

Good luck.

sc4rf4ce

As i said ive got the bolts off. but just one bolt head is rounded.
does anyone know where i can get a good 6 side socket.
ive tried mcquillans, atlantic and halfords.
they all sell 12 side sockets individualy.
im going to try the old hammer the socket on and hope for the best.