Exhaust Noise

[Guest Simon M]

Can anyone tell me what I can do to stop the exhaust making a horrible crackling & popping noise on the overrun? I'm finding myself disengaging the clutch when braking or coasting down hill, to avoid the noise- not the way I like to drive.

Could it be timing or mixture, both of which have been adjusted?

My 2B's fitted with a 2l pinto with the stainless 4 into 1 exhaust, running on unleaded.

Cheers Simon

[Big Jim]

Try checking for leaks on the joints, this will cause it.

[Longboarder]

Another possibility is it could be running a bit rich on overun which carb models tend to do. Mine certainly does the same but as it appeals to the boy racer in me I havn't tried to do anything about it.

 

Nigel

[Guest Ant]

My EFi pinto does this too. It seems to be on overrun with just a tad of pedal pressed. On overrun with no pedal the ECU cuts the fuel completely on an EFi engine I think, and only starts fuelling again as the idle speed is reached.

 

When my car broke down last week (due to a lack of spark) I flooded the engine to the point of having fuel running out of the exhaust pipe. I also had fuel leaking from the exhaust where the 4 pipes are welded into one. Therefore I assume that there is a tiny hole at this point. Is this hole really the cause of the backfiring?

 

Ant

[Guest Peter n the better half]

So youve a ram jet powered 2b ...hmmmm.

reason (only one of them anyway) Some of the fuel / air mixture continues to burn as it passes thru the exhaust. If there is any hole that the low pressure pulse can ''suck'' in then the burn can increase giving a ''POP'' .

The only bad thing is that it can damage the internals of the silencers , believe me ive done it and you dont want to hear the problems i got from the boys in blue when the glass started to be fired out of the exhaust. ' nice light show in the rear view mirror tho.

 

Check all joints for gaps ( use washing up liquid / water mix when the exhaust is cold ie pour it on the joints) bubbles will appear where you have a leak if you place a rag over the exhaust outlet pipe.

 

If that doesnt solve it then i guess your mixture is too rich remember to check it at idle too as well as at partial opening.

[Guest Simon M]

I find it only hapens when my foot is completely off the pedal, a slight touch & it goes away. I had thought it was running rich at idle, maybe I'll give that a tweek & check the exhaust for leaks.

Thanks

Simon

[Shandylegs]

Simon

 

Have you also checked for air leaks on the inlet side of things. I had the same problem and traced this back to a vac pipe tapped into my inlet manifold.

 

Cheers

 

Shandylegs

[Guest Brynjon]

Happens to my 1.6 pinto, but it doesn't appear to be a major problem (as yet) as the weather keeps me from taking her out. It only happens really when approaching the many roundabouts I have near me.

 

 

As an earlier poster stated - it does appeal to the boy racer in me too. Or should that be ole' man racer.

 

[Guest MikeD318]

The best term I have heard is Gentleman racer.

[Guest boggie]

Mine does this and there are no leaks. It's a biproduct of a tuned engine, big carbs and a performance exhaust so in my case cant be helped - but I like it anyway!