Easiest way to remove a 3-piece exhaust?

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Adil786
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Wed May 12, 2010 4:46 pm

Trying to remove the exhaust on a 325i cab to replace the fuel tank. Will prob be able to do this with the exhaust on the car - but the prop gets in the way and won't budge unless the exhaust is off.

Car is on axle stands.

Exhaust won't seperate at the centre join :cry: Have WD40'd it to hell and pryed the joint, hit it a lot with a big club hammer etc and no movement. Reluctant to blow-torch the joint given that there's a corroded fuel tank above it!!! :mad:

I know the manifold joint can be a pain to release given the rust etc so was thinking to remove the manifold off the head and drop the whole exhaust????

Will this go with the car on stands? Or any other tips most appreciated!!!!

TIA
Theo
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Wed May 12, 2010 5:01 pm

By the sounds of it you have a 2 piece exhaust where the rear section joins to the front section shortly after the centre box.

I always remove these in one go by undoing the front section where it meets the exhaust manifold. They're funny sized nuts so make sure you use the right socket, ideally 6 sided and with plenty of WD40.

I wouldn't remove the manifold from the head, you might have the dramas of studs snapping in the cylinder head if you do.
Topblag
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Wed May 12, 2010 5:11 pm

Theo325 wrote:By the sounds of it you have a 2 piece exhaust where the rear section joins to the front section shortly after the centre box.

I always remove these in one go by undoing the front section where it meets the exhaust manifold. They're funny sized nuts so make sure you use the right socket, ideally 6 sided and with plenty of WD40.

I wouldn't remove the manifold from the head, you might have the dramas of studs snapping in the cylinder head if you do.
+ 1.

You'll need some extension bars and a breaker bar to get at them and remove them. The bolt at the top of the join is the hardest to get to IIRC.
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1990 325ix, moredoor auto in Laser Blue. 51k
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weed1
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Wed May 12, 2010 6:14 pm

If you have a concrete floor, four jack stands and a trolley jack.
Buy a can of rust penetrant. WD40 is a water dispersal agent.
1,With the car up on four stands, set the trolley jack close to the tailbox, then undo the tail box.
2, Support the tail box with the jack and move upstream to the secondaries/mid pipe join which you have soaked in penetrant.
3, undo the fasteners at 2, then go after the center mounting hangers if applicable.
You could also have suitably sized items to support the sagging exhaust.



I'm not exactly sure of the hanger arrangement on a regular E30, as I have an E30 M3 which has a slightly different locations for exhaust hangers. On this car it is easy to remove the tailbox/midpipe as a single piece.


m
Adil786
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Wed May 12, 2010 7:14 pm

it could be a two-piece, but there's the back box, with a bolted connection to a centre pipe, then two triangular mating brackets connecting to another centre box which bolts to the manifold... i thought that was 3 pieces :?

yeah used bolt penetrant, "wd40" being the generic name! looks a bit cheapy plain bottle with red 'Penetrating Oil' haha - guess I get what I pay for...

ah well...looks like disconnecting the bugger from the manifold join :(

anyone know what size those 6 bolts are? i changed the head recently and all the studs were good - is it still a possibility to drop the whole thing from the manifold if unbolted from the head? looks tight with the steering rack etc in the way.

anyone near slough have access to a ramp - think it will be easier with the car in the air!!
stonesie
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Wed May 12, 2010 7:44 pm

On mine there are 4 downpipe/manifold Nuts and they need a 14mm 6 sided socket with a long extension bar, you will probably need a new gasket for the join too.

Don't risk a 12 point socket, if you round one off that really will make you swear :wink:
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