10 replies to this topic

[01smartc]

Hi all, i think ive got a exhaust manifold leak .. wht are the symptoms? So i can confirm my thoughts? Cheers Chris

[Retro_10s]

Hi all, i think ive got a exhaust manifold leak .. wht are the symptoms? So i can confirm my thoughts? Cheers Chris

Symptoms off the top of my head:

Dodgey Idle.
Hissing sound.
Hesitant running.

Run the engine, squirt WD40 over the manifold and around the gasket. And see if it shows up any air escpaing i.e. look for bubbles.

Edited by Retro_10s, 28 January 2007 - 05:08 PM.

[Big_Adam]

Normally black soot everywhere shows a leak.

If not take a bit of tissue and cut it into a stip. Then dangle it around the manifold. Is it starts getting blown about then that shows the leak. I suggest this method over using your hand as exhaust are fuggin hot and really....REALLY hurt when they burn.

edit

Damn Mr Retro's ninja like speed!

Edited by Big_Adam, 28 January 2007 - 05:10 PM.

[01smartc]

:S ... im not sure what it is then.... Ok i will tell you whts wrong n then see if any nice person can help me

Firstly when my engine is cold it backfires thorugh the carb.. a kinda pop usually pulling away unda high torque! It can be solved by pulling the choke out a fair bit... when the engine is warm it only "pops" every now and then.. unda extreme torque (a hill)

Secondly i have recently heard a new sound from my engine, quite louds... a cross between a ticking and a hissing/whiring :s (sori to be vauge) It quickens with revs. However my performance has not been affected.

The only thing that has changed is i am using a bit more fuel than normal.

I thort it cld be a leaky manifold gasket because
Air is being sucked in through the manifold under high torque causing the mixture to lean out and cause the 'pop' ... manifold seals better when hot so no leak.
And the other sound i can hear is the exhaust gases escaping from the leak?

Any one got a better idea?

Cheers Chris

Edited by 01smartc, 28 January 2007 - 06:07 PM.

[1275GT zeemax clubman]

sounds like my metro! does exactly the same thing, and my manifold is leaking... is it a split manifold, the steel and cast iron? mine pops and is probably worse than yours as it sounds terrible! ive had it off once to reseal but its gone again and was definatly the manifold

[Big_Adam]

....could very slightly be the spark plugs. I watced an ep of "the garage" were they had a Ferrari somthing which was popping thro the carb, new spark plugs and it was fine.

[ginigwunkle]

have you changed your air filter?

could be sucking more air in causing the whirring noise(like induction kit does)

which could also mean the mixture is richer making missfire.

mine is too rich and i get flames from the exhaust when easing off the gas at high revs!

[Retro_10s]

could be sucking more air in causing the whirring noise(like induction kit does)
which could also mean the mixture is richer making missfire.

More air means a leaner mixture not richer!

You mention adding choke <adds more fuel, making it richer> helps stop the popping.

[01smartc]

I have been told it mite be running to rich.. this causes the popping because the extra fuel goin through suddenly combusts and causes a pop... wht do we tink of that?

[mini1976]

Have you tried checking your timing as my car used to pop and back fire and it was all cured but getting the timing set right. As far as your exhuast leaking. When the engine is cold and ticking over. put you hand over the end of the exhaust. Pressure should build up and you hear no hissing. If you can hear a hissing noise then you know you have a leak. If you cant the engine should start to stall cause of the back pressure stopping the exhaust gasses getting out.

[Protarmic]

Normally black soot everywhere shows a leak.

If not take a bit of tissue and cut it into a stip. Then dangle it around the manifold. Is it starts getting blown about then that shows the leak. I suggest this method over using your hand as exhaust are fuggin hot and really....REALLY hurt when they burn.

edit

Damn Mr Retro's ninja like speed!

What a great idea! Ive tried the washing up liquid method but couldnt see bubbles.. I'll have to try this trick tomorrow, thanks Big Adam.