Possible inlet manifold leak

vanquishspirit · Post by **vanquishspirit** » Tue Mar 25, 2014 6:30 pm

I am wondering if there is a quick and fail safe way to diagnose a leaking in,et manifold. I am thinking my cars poor starting and misfiring could be down to air leaks own the inlet manifold causing it to run too weak. I do t want to take the manifold off in case it's not the problem. Any ideas guys.

ppyvabw · Post by **ppyvabw** » Tue Mar 25, 2014 6:36 pm

I'd use the old trick of getting a piece of tube and putting it to your ear and listening round the gaskets and stuff for leaks. Also, I've heard of people squirting WD40 around, and if there's a leak the engine tone will drop - never done that myself though.

vanquishspirit · Post by **vanquishspirit** » Tue Mar 25, 2014 6:42 pm

Ok. Thanks for that. I will try that. I must say there is a high pitched squeak which could indicate a leak. Tricky one this !

mgbv8 · Post by **mgbv8** » Tue Mar 25, 2014 7:26 pm

Some folk run the engine at high idle and spray WD40 on the joints you can get to. If it gets sucked in you will hear the engine note and revs change.

ChrisJC · Post by **ChrisJC** » Tue Mar 25, 2014 7:31 pm

You could try just tightening the manifold bolts - they have a habit of not being very tight!

Chris.

vanquishspirit · Post by **vanquishspirit** » Tue Mar 25, 2014 7:31 pm

Thanks. What's worrying me is that I coupled up the heater pipes the wrong way around on rebuilding the engine. Net result was the inlet manifold got seriously hot ever since it has run dreadfully and hard to start. Checked ignition, carbs timing etc. no water in oil or vice versa so only thing left really is an air leak on some of the pots. Think I may as well just whip it off and be done with it.

vanquishspirit · Post by **vanquishspirit** » Tue Mar 25, 2014 7:34 pm

ChrisJC wrote:You could try just tightening the manifold bolts - they have a habit of not being very tight!

Chris.[/quot

I tried that , not very convincingly though so maybe check the ones I didn't bother with....the hard to reach ones. I have an old tin gasket on, may change to a composite at the same Time

mgbv8 · Post by **mgbv8** » Tue Mar 25, 2014 8:18 pm

vanquishspirit wrote:
ChrisJC wrote:You could try just tightening the manifold bolts - they have a habit of not being very tight!

Chris.[/quot

I tried that , not very convincingly though so maybe check the ones I didn't bother with....the hard to reach ones. I have an old tin gasket on, may change to a composite at the same Time

Deffo change the tin valley gasket for a Comp gasket

Its actually just a tin gasket with a foam type coating. But they seal up really well.

vanquishspirit · Post by **vanquishspirit** » Wed Mar 26, 2014 5:42 pm

It was the inlet manifold gasket guys. I started it up, sprayed some carb cleaner round the inlet manifold and it sucked it in. I think I got the engine too hot due to an air lock and toasted the gasket. Fitted a new composite gasket, no sealant, and so far it's holding. Fingers crossed. Surprised how hot the inlet manifold gets. Thanks for all your help chaps.

mgbv8 · Post by **mgbv8** » Wed Mar 26, 2014 9:19 pm

vanquishspirit wrote:It was the inlet manifold gasket guys. I started it up, sprayed some carb cleaner round the inlet manifold and it sucked it in. I think I got the engine too hot due to an air lock and toasted the gasket. Fitted a new composite gasket, no sealant, and so far it's holding. Fingers crossed. Surprised how hot the inlet manifold gets. Thanks for all your help chaps.

RESULT