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MG MGF Technical - Stuttering/gurgling exhaust

As well as my fueling and power problems , I have notcied that the exhaust gases do not come out of the exhaust properly (at least I dont think).

When I blip the throttle there's a lot of gurgling/popping etc but even when idling when you put your hand to the exhaust pipes, the gasses do not come out smoothly, instead its like a phut phut kind of noise and you can feel a burst of gas, then nothing, then abigger burst, then nothing, in no particular time order, just random.

Could this be a reuslt of overfuelling, or a faulty exhaust?
I Brown

I to get that sound from my exhaust but mine want's replacing because it has a hole in the rear box! It might be that; don't know if that might helps.
Colin
Colin

could be the cat mines going. loss in power rumbling noise when i put the throttle down revs .
darren jeffery

That much disruption to the exhaust gas flow suggests a disparity between the volumes coming out of each of the 4 exhaust ports, creating turbulences which the rest of the system magnifies. Popping usually indicates unburnt fuel passing through the exhaust ports and combusting in the manifold & downpipe. You could try disconnecting each injector in turn and seeing if that points to one particular cylinder; running on three cylinders will give a varying gasflow at the exit pipe but it should be a consistent pattern.
Mike Hankin

Thanks folks.

Darren, sounds like mine, loss of power and loud noise when I put the foot down but with no acceleraiton to accompany noise...however, I have just replaced the cat , but at the moment I am running a hollowed cat to see if it improves my power problem etc .. It doesn't!

Colin, I do actually have a hole in back box, fileld with GunGum butdoesnt sem to help.. however, I also acquired a new X-power Throughflow exhaust as of today , I will hopefully fit tomorrow, again to see if it helps any.


If not, I will try Mikes suggesitons. Thanks. I have done a compression test and all 4 cylinders seem to be within range of each other, but have not tried disconecting injectors.

Most sensors have been changed so not sure why its still overfuelling unless ECU is caput?

Will let you know how it goes tomorrow with new exhaust and with injector test
I Brown

Sounds like a leaking exhaust joint to me TBH.

"Popping usually indicates unburnt fuel passing through the exhaust ports and combusting in the manifold & downpipe."

Any 4 stroke engine will pass unburnt fuel through the exhaust valve since not all the fuel is burnt - mix that with an air leak in the exhaust and you will get popping, especially on over run.
Deborah Evans

Thanks Deborah, so my new exhaust should cure it. Yes, it is indeed on overrun
I Brown

Hi, fitted new exhaust and it is nowhere near as bad as before.

Mike tried ot disconnect injectors but it obiously not just a case of unplug them as I could not reach the multiplugs so I never bothered :)

Thanks for the help
I Brown

hi mr i brown was it a hard job to replace the kat then darren
darren jeffery

Well, it took the guy at the garage about 4 hours!!


Its easy to do as I havew taken mine off a few times since then but he had to grind away all the bolts, then knock out what was left of them. If the bolts are OK, they you may be finw.

The lamda sesnor, well thats what took up about 2 of those hours. It was literally welded into the cat. Eventually he had to actually weld a pair of mole grips onto the sensor then use a hammmer to get it off. Luckily the threads did not stripo so I could replace it back on the new cat.

This was done off the car obviously once the cat had been rmeoved.

IF the nuts/bolts are not too bad then it can be done in about 10 mins max. IF not , then it could be a nightmare.

Can you actually still see the bolts or are they like mine were, now "part of " the cat?

I would also take P/S rear wheel of asit makes it easier to access on a 2001 shape of cat
I Brown

This thread was discussed between 15/09/2006 and 22/09/2006

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