Exhaust manifold

[ETERNITY]

BMW 325i sport

Changed the exhaust and the manifold is only connected with only 2 bolts because the other two have snapped

It's sounds awful now

Can the maifold come off easily without removing engine

[daimlerman]

Be very careful how you tackle the manifold/head studs!
As you have discovered,the studs rust and fail for fun.The cast manifold has a tendency to warp 'banana' shaped over time,this causes the end studs(cylinders 1 and 6)to snap the studs or just pull the studs out of the alloy head.

A stud that has a bit showing when the manifold is off is not too bad,it may be possible to weld a nut to the remains and turn it out,but one snapped within the head is very bad news.

So lots of WD40,slacken,tighten,slacken,tighten until the blighters will un-wind without snapping.

[ETERNITY]

Update

Manifold came off easy

After re assembling the manifold there is a loud noise now coming from the engine bay

Has the mechanic Damaged my head by tightening the studs to far in because he did mention that there was a ting noise as he was bolting up

[Rallyprep_UK]

I always replace them with new !

I had one snap off in the head once. I NEVER EVER want that nightmare again !!!

Some good advice here too from the other guys !

Will

[ETERNITY]

Come on and bear me with the good news

what's the damage

[Rallyprep_UK]

probably snapped a stud, it will have to come off again to be sure.

hopefully there is enough left sticking out of the head to remove it if this is the case...

Will

[ETERNITY]

He seems to think the head has been damaged and is talking about taking of the manifold to see whats happened and then weld the damaged area on the head if there is any Damage

There's a loud blowing Tractor noise

[aze30]

ouch...feel for you shaz will bell you tomorra

[capri_rob]

Sounds like he's snapped at least 1 stud by overtightening

Can't see how the head would actually be damaged

Did you have the manifold checked to ensure it was flat before trying to put it back on ?

Mine apparently was bent like a banana although it looked ok - needed a machine shop to skim it flat again.

Depending which stud is snapped the head may well need to come off- if its any of the ones near the bulkhead end forget trying to sort it with the head on.

[ETERNITY]

Ok the manifold actually didn't go on flushed and after a couple of attempts it went on flushed

I don't think there is any broken studs however
Ver there are two studs that aren't secure because there not tightening

Ermm

[Grrrmachine]

That's what your mechanic meant by "damaging the head." It sounds like he's stripped the thread in those holes by overtightening.

Which studs are they? If you're lucky you'll be able to get access to them and helicoil the holes without having to take the head off.

[AlpineCab]

even BMW dealers get the experts in to deal with the whole exhaust manifold/head stud job, and they aint too expensive either. IIRC Wood BMW odiham used to use a guy that charged around £50 for the whole lot i.e studs extracted and changed over - it's all he does for all dealers in the area so he had all the specialist kit ever invented.

One idea for the exahust and manifold could be to use copper plated nuts? - loads on ebay.

[Grrrmachine]

One idea for the exahust and manifold could be to use copper plated nuts? - loads on ebay.

Like this:



(fitted last month)

[capri_rob]

Used them on mine - bought from the dealers

[ETERNITY]

It's the manifold that didn't sit flushed

It's 1/2mm out

he only touched the side of the block and dented it slightly. It's away from the bore, so that should be fine

Also the last stud needs to come out but won't because it's on the end one, difficult to get to. Tried a stood extractor

Whats the best Option

6 branch manifold

Skim the manifold

Or get a second hand one

[ETERNITY]

So will it be ok using a the manifold 1/2mm out and also without 1 stud being bolted

Because In reality there all going to sit not totally flushed and also I have new gaskets anyway

[DanThe]

Sounds like you need to find somebody that knows what they are doing for a start, then the first job will be sorting out the mess thats been made of the head

[ETERNITY]

It's very slight and doesn't really need sorting because it's away from the bore and a tiny little mark on the block

[ETERNITY]

Any links to where I can get these copper plated nuts

Cotswold only stock studs and nuts combined

Thanks

[sweep]

I dont understand any of this?

[ETERNITY]

Its sorted now

Apparently most common issue that happens when taking off exhaust manifold

[sweep]

Was it blowing?

[ETERNITY]

Yes big time

Mechanic panicked that he had damaged my head

Lol