8 replies to this topic

[Touche Away]

OK, so I'm now going to be replacing the manifold gasket on my Mainstream for the third time in as many months.

Each time I fit it, I use a decent quality gasket and go around both sides of it on the outside and between the inlets with FireGum, but every time, within a few weeeks, it's blowing again.

I did think that it was because the engine was moving about, so I replaced the tie-rod bushes, but the latest gasket has started blowing yesterday!

My local garage fitted the first one and couldn't get it right, so I've done the last two myself.

Any hints or tips to save me loosing what little hair I have left?

Cheers

Gav

[Turbo Nick]

dont put any sealant on the gasket it doesn't need it.

check to see if the manifold faces are flat and are the same thickness so they clamp down properly.

[biggav]

i got new studs, nuts and washers from mini spares (only a few quid) and got the extra long nuts for behind the inlet manifold so its easier to get a socket on. also got the higher performance manifold (thicker and bigger ports)

[black jack1275]

Are you useing a separate inlet/exhaust manifold or an standard one?
some of the aftermarket ones have a different flange thickness ie. maniflow exhaust and mg inlet, the mg inlet is thicker so you have to file it down to fit it.
you shouldnt need to use firegum on the gasket just clean the mating faces
hope this helps

[Ethel]

If none of the above works, bet it does, could be your exhaust is too solid - use a solid strap onto the bottom of the engine but keep it fairly flexible behind that.

[Udo]

As above Gav, only use the gasket and if the inlet or exhaust has been altered from standard check that the two flange faces are the same thickness else you'll never get a seal

If you need a hand at all give me a shout

cheers

[Touche Away]

As above Gav, only use the gasket and if the inlet or exhaust has been altered from standard check that the two flange faces are the same thickness else you'll never get a seal

If you need a hand at all give me a shout

cheers

They aren't the same thickness, I've been using some washers to try and level it all out a bit.

I might well take you up on the offer as this is doing my swede in having to refit it once a month.

Cheers

Gav

[ginigwunkle]

filing arther than spacer washers is more reliable as you can get the same thickness where as you say, washers only "try and level it all out a bit."

also i got a thick almost metal type manifold for minewith inserts and large port holes, cost about 4 quid as apose to the 50p ish of the std but never had a problem since!

[Jimmyarm]

slip a small smear of grease on both sides on the manifold but no sealant

As above, if the 'flanges' (hehehe) are level then you wont get it too seal.

Gave can you linky those long nuts as I need to change my manifold and the end one on the 998 where the breather can is, is a complete PITA. I cant get any of my sockets on it so ended up using a ring spanner last time which mashed it up a bit