Tips on exhaust manifold gasket change
Discussion
Hi guys - going to attempt to remove my exhause manifolds this weekend, despite having huge hands and little patience!
Anyway, someone mentioned that slackening the bolts when the engines hot would help ease them out. I'm not sure i could handle the heat as it looks quite tight. Any thoughts?
And while on the subject, what the best method for getting them to seal? Are they better put on dry or with some sort of high temp sealant? It's a job i only want to do once!
Anyway, someone mentioned that slackening the bolts when the engines hot would help ease them out. I'm not sure i could handle the heat as it looks quite tight. Any thoughts?
And while on the subject, what the best method for getting them to seal? Are they better put on dry or with some sort of high temp sealant? It's a job i only want to do once!
Here you go with a starter for 10 then:
Give them a good clean off with a wire brush, spray a little penetrating fluid on them... Loosen & tighten back up as many as you can over the week before you commit to do the job....
Get the car up on ramps so you can get under to release the starter and work from underneath if necessary.. You may need to strip alt / swirl tank off front of engine to get manifolds out YMMV..
ARP bolts for reassembly seem to be default these days, and new spring washers IMHO, I wouldn't re-use the original bolts after all the tales of woe.
Get ready to bend an appropriate spanner to suit
Dave
Give them a good clean off with a wire brush, spray a little penetrating fluid on them... Loosen & tighten back up as many as you can over the week before you commit to do the job....
Get the car up on ramps so you can get under to release the starter and work from underneath if necessary.. You may need to strip alt / swirl tank off front of engine to get manifolds out YMMV..
ARP bolts for reassembly seem to be default these days, and new spring washers IMHO, I wouldn't re-use the original bolts after all the tales of woe.
Get ready to bend an appropriate spanner to suit
Dave
I was happy with the later LR metal sandwich ones... others have different preferences. Arm yourself with some rubber bands, cotton / string to hold them in position while you fit the manifolds.
Make a note of the bolts which won't withdraw, as you need to put these back first on reassembly (not sure if all manifolds have this problem..)
You prob have the clamped manifolds (not flanged) so I think some people use various compounds to seal them... and thumbscrews to pull them into position? ( just gloating cos I like the flanges
)
Dave
Make a note of the bolts which won't withdraw, as you need to put these back first on reassembly (not sure if all manifolds have this problem..)
You prob have the clamped manifolds (not flanged) so I think some people use various compounds to seal them... and thumbscrews to pull them into position? ( just gloating cos I like the flanges
)Dave
Meatball said:
My advice is pay a local garage to do it, my hands were a mess!!!!
Yep, I don't have a garage or any type of lift other than a scissor jack. A pal, who once worked at a TVR dealership, replaced the gaskets some 5 years ago, cash.Over the past two weeks though, the engine has been sounding like a tractor and I've realised they need replacing again. Ordered and received (very promptly) new gaskets and bolts from Tim (ACT) and I (cautiously) asked the indie I've been using for 3 years if they'd undertake the task. I advised that it could take up to two hours per side. Booked in for Tuesday- hope to collect it around 5.30 that day.
Metal gaskets, ARP bolts with new spring washers, buy or borrow a 14mm flank drive Snap On spanner and a ratchet spanner to remove bolts, I personally do it from cold as I am not fond of skin grafts!
Use either a dead blow or hide hammer to gently tap the Y piece away from the manifolds, lightly clean the theads in the head before reassembling, do not use any paste, attach the gaskets with cotton while you catch the bolts, before final tightening connect Y piece.
Use either a dead blow or hide hammer to gently tap the Y piece away from the manifolds, lightly clean the theads in the head before reassembling, do not use any paste, attach the gaskets with cotton while you catch the bolts, before final tightening connect Y piece.
Bomber Denton said:
before final tightening connect Y piece.
I prefer to get the manifolds torqued down first so the bolts aren't fighting against anything as you pull them down. It gives them a much easier time, and postpones the day when you pull the threads out of the head. It's easy enough to spring the manifolds into place to fit the Y piece afterwards.Crickey, no-one was kidding when they said it's not straight forward! Attemted the driver's side first, started around half 3 in the afternoon and by 8 I still hadn't got one side off! Cutting and bending my favorite spanner help smooth thing along. But then taking off the starter turned into a nighmare in itself!
The leak has started because number 1 cylider (the hard ones at the back) had very loose bolts - all came off with a load crack except these, and one was missing from the passenger side! Suspicious, but i checked and there wasn't a snapped stud inside the head, screwed a spare one all the way in to make sure.
Anyway dropped of the exhaust for the passenger side and all was going well until my finely tuned spanner snapped - no surprise as i'd be a bit enthusastic with the trimming. This now has ever so slighly rounded the nut, so i'm not taking any risks and i'm going to get a decent 6 sided ring spanner for the job, if one exists/i can get one.
Can anyone offer any advice?! I reckon it isn't outside the realms of possibility that i could get some heat on it, but it's very risky. The nut's still ok, a normal 14 is still a good fit but by the time i've extended it with another spanner the get the leaverage i reckon it'll round off. Shame because it's the last stud!!
A six sided socked does fit well but i can't get in with a ratchet.
Pretty frustrating!
The leak has started because number 1 cylider (the hard ones at the back) had very loose bolts - all came off with a load crack except these, and one was missing from the passenger side! Suspicious, but i checked and there wasn't a snapped stud inside the head, screwed a spare one all the way in to make sure.
Anyway dropped of the exhaust for the passenger side and all was going well until my finely tuned spanner snapped - no surprise as i'd be a bit enthusastic with the trimming. This now has ever so slighly rounded the nut, so i'm not taking any risks and i'm going to get a decent 6 sided ring spanner for the job, if one exists/i can get one.
Can anyone offer any advice?! I reckon it isn't outside the realms of possibility that i could get some heat on it, but it's very risky. The nut's still ok, a normal 14 is still a good fit but by the time i've extended it with another spanner the get the leaverage i reckon it'll round off. Shame because it's the last stud!!
A six sided socked does fit well but i can't get in with a ratchet.
Pretty frustrating!
My V8S has Chim manifolds and they're fitted and removed working entirely from above - no need to disturb the starter motor etc. However, on mine the alt does have to come off to give access to the driver's side.
The bolts are nominally 9/16" AF. A 14mm spanner is a fraction under size which helps get a good tight grip and avoid slipping.
The bolts are nominally 9/16" AF. A 14mm spanner is a fraction under size which helps get a good tight grip and avoid slipping.
So - an update, mainly for anyone who has thought about doing this job themselves...
After getting the drivers side manifold off (removing the starter) and getting down to one very, very tight bolt underneath on the the easier to get too passenger side (exhaust off though), i'd almost resigned myself to the head off approach.
But where there's a will, there's a way:
I bought a 1/4" drive ratchet spanner socket adaptor (halfrauds), used a 10mm ring spanner the wrong way round and a 14mm six sided socket. Which just fitted between the manifold and the chassis rail. Then, (halfrauds again) using a brazing torch i very carefully (fire extiguisher to hand, avoiding newly applied waxoyl/engine oil etc) applied heat to the head/mainfold/bolt. Then gave it the good news, low and behold it moved, and all was well with the world!
The bolt appears to have brought out some ally thread with it on a few threads:
But i'm not too worried
While i was taking pics, here's my two knackered spanners that i sacrificed:
and obvious evidence of a badly blowing manifold:
First picture post so i apologise in advance if there're massive or don't work!!
After getting the drivers side manifold off (removing the starter) and getting down to one very, very tight bolt underneath on the the easier to get too passenger side (exhaust off though), i'd almost resigned myself to the head off approach.
But where there's a will, there's a way:
I bought a 1/4" drive ratchet spanner socket adaptor (halfrauds), used a 10mm ring spanner the wrong way round and a 14mm six sided socket. Which just fitted between the manifold and the chassis rail. Then, (halfrauds again) using a brazing torch i very carefully (fire extiguisher to hand, avoiding newly applied waxoyl/engine oil etc) applied heat to the head/mainfold/bolt. Then gave it the good news, low and behold it moved, and all was well with the world!
The bolt appears to have brought out some ally thread with it on a few threads:
But i'm not too worried
While i was taking pics, here's my two knackered spanners that i sacrificed:
and obvious evidence of a badly blowing manifold:
First picture post so i apologise in advance if there're massive or don't work!!
Edited by jonny_c on Saturday 23 February 21:57
This did occur to me - the 'rear' cylinder has been is very bad because it was missing a bolt. Who knows for how long. And i reckon spending too much time with sandpaper cleaning up the surfaces could make the flatness worse....
I'll probably take the risk and change the gaskets first, like i've said, stripping off the heads will snowball into a full rebuild if i'm not carefull, so i'm trying my hardest to avoid it because i penciled that job for next winter!
I'll probably take the risk and change the gaskets first, like i've said, stripping off the heads will snowball into a full rebuild if i'm not carefull, so i'm trying my hardest to avoid it because i penciled that job for next winter!
Do yourself a favour,put a couple of hacksaw cuts down the length of the thread on one of the old bolts and run in and out of the 16 holes to clear the accumulated crap in the threads WD40/plus gas or similar is good at assisting this job and flushing out the muck from the threads as you move the bolt in and out,then just wire brush the crap from the bolt everytime you do a cylinders worth,this aids in being able to spin the bolts in with your fingers on assembly an antiseize compound is recommended on the bolts on assembly,after approx 1k miles recheck the bolt tightness on those manifolds.
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