Manifold gasket blowing!

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lux93drop
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Joined: Fri Sep 30, 2005 11:00 pm

Post Fri Oct 14, 2005 7:47 pm

Evening guys. The exhaust manifold gasket on my 318i M40 1.8 is blowing, gradually getting louder and louder. How hard is it to fix your self? Do the bolts always snap off? Does it take long and lastly why does it get quieter as the engine heats and gets the gasses warmer? :cry:
smithy318i
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Location: Tyne & Wear

Post Fri Oct 14, 2005 7:55 pm

Quite easy to fix yourself.

remove the downpipe.

remove the manifold bolts and manifold.

replace gasket.

I havn't had a bolt snap off yet.

No idea on the noise question.
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JOSEMI
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Joined: Thu Oct 13, 2005 11:00 pm
Location: Eastbourne

Post Fri Oct 14, 2005 8:00 pm

It looks worst than it really is. I am restring mine and a mechanic friend of mine is sorting this out for me, but he gave me the following tips:
* The old copper bolts will most probably snap.
* Buy new bolts, all the 12 ! And beware that the set may cost you around Ԛ£350 from the BMW dealers !
* I found new gaskets in ebay from a tener, although they are for a six cilinder I am sure the 4-cylinder ones are not too expensive.
* Check very carefully the state of the manifold for cracks and any signs of deterioration.
When the engine and the manifold get warmer they expand and make the joints' gaps get smoller, letting less gas escape through the cracks.
God luck with yours