manifold studs help!

Post by **shimon340** » 09 Jan 2006 02:54 pm

Hello!

Hey guys... need some advice please...

Im working on a volvo 740 B230K. Need to remove the exhaust manifold in order to remove the pulsair pipework and then plug the pulsair system.

For 6 of the manifold nuts, they have come off alone which is cool but undoing two of the nuts has simply undone the studs ie two studs have come out the head...

question is... how do I get the nuts off the stud now its removed from the engine... any tricks / tips on how to do this?

I know you can use two nuts tightened together to put the stud back in the head but how do you get a nut off a stud once its come out?

vice?

replace studs ( would rather avoid this as they are £8 each...

I guess this is a common problem with slightly older engines and rust bolts....

look forward to hearing from you

Shimon

Foggy... did you have this prob on nessy's exhaust manifold?

Post by **Chesh740R** » 09 Jan 2006 04:12 pm

Hmm tis a bit tricky really to get the nut of the stud without damaging the threads. Only way to do it is clamp it lightly in a vice using two soft bits of wood either side, and then heat the stud and nut up till its glowing hot and it then should undo.

If you object to paying £8 per stud, then simply screw the stud back in using the siezed nut on it.

I've done this plenty of times on cars when the car isnt really worth spending much cash on.

If however you intended to keep the car, then i suggest changing the studs as dealing with a snapped of stud in a head is a lot more expensive than £8 per stud.

Post by **Bilbo** » 09 Jan 2006 04:55 pm

get 2 nuts to fit the end with no nut on and tighten up on each other so they lock together. these will lock hard enough to hold with a spanner,then loosen the side you want off{after giving it a wire brush/oiling}. then just simply remove the 2 nuts you used as "lock"
works everytime for me..........

Post by **shimon340** » 09 Jan 2006 08:09 pm

hi guys

thanks for the info...

I spoke to a mechanic at volvo and a friend of mine with a garage and they advised to put the bolt in a vice and then undo the nut. Ive tried this on the first bolt and it came undone nice and easily.

looking at brickboard.com there is a lot of info all about snapped studs in heads....

Volvo dealership mechanic's advice was...

Dont need to use antiseize compound when putting the studs into the head. Seeing that all the studs have come out instead of the nut undoing means I prob dont need any antiseize compound. If I do decide to use some then brickboard advises using an aluminium based anti-seize compound. What do you guys reckon?

Using two nuts locked together the studs can then be reinstalled.

The manifold should be tightened from the middle outwards to avoid warping it. Of the guys who have changed a manifold here what is the pattern of tightening the nuts?

Ive got new gaskets from volvo for the exhaust manifold also..........

cheers guys

Post by **pettaw** » 09 Jan 2006 09:15 pm

Chesh is right. When I took my engine apart, a few exhaust manifold stud unscrewed. You clamp the stud in a vice using soft wood so you don't bugger up the threads and then you heat the nut for a couple of minutes. Then you can undo it. Then to make sure you can get the nut back on again, after its cooled, wire brush the threads with plenty of WD-40 and then turn the nut on and off several times until its easier.

TBH its easier to buy new nuts and studs

Post by **shimon340** » 09 Jan 2006 10:30 pm

true... it is easier to buy new studs and nuts but at £8 and this car needs 7 or 8 ... its not my car so the owner doesnt want to pay 50quid extra...

what about the tightening sequence for manifolds... foggy... dai?? any info?

Post by **shimon340** » 09 Jan 2006 10:30 pm

thanks pettaw for your advice!

Post by **foggyjames** » 10 Jan 2006 01:36 am

I did this very thing tonight on Nessy...twice!

Quick spray with WD40, wait 5 mins, two nuts on the short end good and tight....then crack the stuck one off. Job done.

cheers

James

Post by **shimon340** » 10 Jan 2006 01:40 am

were you removing or refitting the manifold? whats the order of retightening the bolts?

Post by **foggyjames** » 10 Jan 2006 02:39 pm

Removing....4 nuts in total brought their studs with them. I'm not aware that there is a correct sequence like there is with head bolts...but I'd not start at one end and work towards the other!

cheers

James

Post by **classicswede** » 10 Jan 2006 09:22 pm

No sequence needed. Just nip em up then fully tighten. I've never warped one of these manifolds yet. What is the reson fot removing the pulsair system?

The only reason I would do it is for lpg.

Post by **shimon340** » 10 Jan 2006 09:48 pm

the pulsair pipe has a hole in it and its an MOT failure so volvo want £98 for a new one... i might be able to get a replacement from CP Motors for 30 quid

To remove the pulsair you need to remove the manifold. The pulsair pipes can then be removed from the head. Volvo make blanking plates for the holes in the head which I have ( £1.30 each ) so Im going to fit these.

Its my friends car and not mine. Apparantly its quite common for the pulsair to fail ( normally the valves fail instead of the pipe ). I looked up brickboard and most people remove it once it causes problems. Emissions are worse though but not so bad as to fail an MOT.

some guys use swedish half crowns to cover the pulsair holes in the head... hee hee

and vadis pic

Post by **340GLT** » 11 Jan 2006 12:28 am

Dude you use CP Motors in Tmaworth?? I know them pretty well, its where i had the blueline panels from!!!
Cheers Adam

Post by **shimon340** » 11 Jan 2006 05:02 pm

yep... CP motors... i got their contact details from the volvo owners club magazine... the guy was really helpful!

which blue line panels did you get from them?

Post by **340GLT** » 11 Jan 2006 09:08 pm

Had a bonnet a hatch and two front doors all in the right body colour!!! lol
Got them all in the back of my car too!!! They were well impressed. The bloke who works there called Dave has a black 360GLT with a 2.3 lump!!
Cheers Adam