Exhaust Manifold Gasket Changing

[beavis2k4]

Hey folks just got my hands on my new motor. A 325 which has 2 problems one of which is the exhaust manifold gasket, Im going to try and change it on the weekend, have never done one before...any help or pointers would be brill!! A tech guide would be spot on

I also have a small fuel leak which i have investigated and am also going to try and fix on the weekend but i need to drop the fuel tank for it.

Just now im getting 22.5mpg i dont know how far of the mark this figure is but im sure i will see an improvment when i get these problems fixed

As i said before ANY help would be brill !!

[Brianmoooore]

Why is the exhaust manifold gasket blown is the first question?
Usually because of a broken off stud, and it's very difficult to remove a broken stud from the head without removing the head or the whole engine from the car.
Apply plenty of WD40 or similar to the nuts several times for a few days before you start this job, and take the greatest care not to break any studs.
Use a nut splitter or grinder on any that are reluctant if you can, but access is difficult.

[Simon13]

dropping the fuel tank is a major job! u have to drop the rear axle out! are u sure it's not the filler neck rusted and leaking when u fill the tank right up? Or old rubber fuel lines in the engine bay?

manifold gasket hmmmm do it when it's hot, mind your fingers, studs will break very easily so be careful. Another not very easy job to be honest and u will probably find that some of the studs are alredy broken too.

[Brianmoooore]

Don't have to touch the rear axle/beam to get a fuel tank out.
Rear of prop and rear of exhaust have to go though.
While you've got the fuel tank out, check the rear brake pipes.

[beavis2k4]

the leak looks like it is coming from the filler pipe but the bit it connects to the fuel tank which is sitting right above the beam that connects the rear jacking points and i cant get access to it why do they make things so difficult ? it also could be the wall of the fuel tank? If i stuck the car into a bmw garage to get the manifold done how long and how much am i looking at?

[Brianmoooore]

The little stub pipe into the tank is where the fuel tank fails. I did manage to repair one once, but welding/brazing petrol tanks is really only for the insane.
garage would have the same problems with the manifold as you, and the average grease monkey would probably shear half of them.

[beavis2k4]

well in that case ill either swap the tank over with my spare one thats sitting on my 320 or ill buy it a new one.
As for the gasket, what do you propose i do? i really nead it fixed

[A1BMW325iSport]

there is a product you can buy called "petro patch" used it a few years ago on an old ford orion i had, managed to patch up round the leaking area and i could fill that tank up after that it worked well

[tomstickland]

Manifold gasket is in principle simpe enough. But in practice you have to be very careful about rusted up studs.
Three things that seized bolts hate are:
-shock impact
-heat
-WD40

I'd douse the whole lot in WD40 the night before doing any work on it; if you're really uptight, keep going out every 30 minutes and douse more of it on.

[craigieeb]

when you get a new exhaust gasgate be sure to get one from the steelers and not e.c.p (euro car parts) the ones from the dealers have a sort of a metal trim around the outer edge which is a good thing, as the one's from e.c.p dont, and fek me are the edges sharp, when i found out as the ratchet sliped of the nut!!!

[Adammcf]

Basically this was a c*** of a job on my car as the studs had pretty much all seized. I had to soak them all in WD40 and them come back at them the next day. Be gentle when loosening them as you dont want to snap any off in the head. I managed to get all mine out which was nice.

Here you can see the remains of my old gasket!


Also make sure you get the correct size gasket for the downpipe. There are two and I ended up with the smaller one at first and had to put it all back together to go get it changed for the larger one!



Its also worth getting a whole set of new studs as well as they are only about 12p each.

[Simon]

I did this job recently on the touring, had been putting it off for nearly a year, when I decided to do it one day, lucky for me, I could undo nearly every stud by hand, only 2 needed some pressure, I then wondered why I hadn't tackled it earlier!! I also doused them with penetrative fluid for a couple of days leading upto the job, and also did it with the engine as hot as I could bear doing it, this helps too!

[e30_Turbo]

Its also worth getting a whole set of new studs as well as they are only about 12p each.

Agreed, I removed the manifold and 10 studs came out, so new ones are a damn good idea

[beavis2k4]

maybe a stupid question but how do you put the new studs in? where can i get them from as i live in the middle of nowhere can you order them online?
thanks for all your help so far guys!!

[Hoggy]

hello Carl,hope the beast isn't giving you too much trouble m8,to put the studs in you screw them in as far as you can by hand then put 2 nuts on back to back and nip them together,screw the stud in with the last nut,it should tighten together and screw the stud in,then loosen the two nuts ,take them off the stud and voila! you have the stud seated in the head,don't put threadlock or anything similar on,but if you've got a bit of copperslip grease that wouldn't be a bad move,keep me up to date on your progress m8,Paul