The V8 Owners Forum -

Whilst playing around under the bonnet today I noticed after turning the engine off a hissing / sizzling noise. It turned out that it was coming from where the inlet manifold meets the cylinder head between the first 2 bolts. There was a very slight water leak that was boiling out of the joint.

Is this just a bad seal with the gasket or am I looking at a major problem?

Will replacing the tin gasket witha composite one help?

Thanks

Jon

I thought the compo ones were supposed to be generally better than tin, though never struggled with a tin one. The compo should be easier to get into place and my ones never needed any sealant either, though I did put the tiniest smear round an iffy looking surface nr one port.
cheers,
Bill

i must confess i use a small smear on the compo inlet faces,
BUT this time i never and i have a small water leak, it fills the back of the valley up after being left for a few days,
so when i strip the top down and put back together it will defo have a smear this time,

i just fitted a comp to mine sealed on the head but not on the intake manifold

hoping it doesnt leak but seeing as im not connected up reaaaly yet i may just whip it back off tomorrow

i never sealed it on the last engine anywhere and come to think of it i had a puddle of coolant at the back of the gasket too but that was probably due to the heater pipes clips forgeting to be tightened and i never bothered to dry it up


i reckon i will pull it back off to seal on the manifold be a pain but worth it

i use hylomar blue by the way

but i think the idea of the composite gasket is so you dont need to seal the gasket

Depends which comp gasket you get, the factory gasket has a kinda rubber coating on it and seals great just on its own. The other type (felpro I think) is a shiny hard surface much like the comp head gaskets, I have seen these leak more than a few times when fitted dry.

the one i fitted was the one that rpi sent me out a year or so back and thats just got the coating

reckon i will pull the manifold off again

pain in the arse taking the injectors off but worth it i reckon

whole reason im putting a new engine in is cos i took short cuts last one and it leaked like a sieve


anyway sorry im thread hijacking here

I always used the factory composite gasket dry on manifold faces. Just some sealer around the rubber valley gasket.

I never had any leaks.

righty ho going back to this one

i sealed the valley gasket (rpi teflon coated job)

used hylomar around the water ports

once the engine was started must have ran for about 30 secconds and i watched coolant running down the gasket in the valley from around the water port next to cyl number 2

reckon ill try it unsealed next time and see what happens i never sealed it on the last engine and it never leaked