Exhaust backfires

[Mikes2esprit1979]

When i take my S2 for a short drive (approx 10-15 mins) then turn the engine off it backfires through the exhaust.

Seems to be ok on longer distance driving though.

Ive got a custom exhaust which i now have photos in the garage section but it still backfired when i had the standard exhaust fitted.

Does anyone know how to cure the problem???

[peteyg]

When i take my S2 for a short drive (approx 10-15 mins) then turn the engine off it backfires through the exhaust.

Seems to be ok on longer distance driving though.

Ive got a custom exhaust which i now have photos in the garage section but it still backfired when i had the standard exhaust fitted.

Does anyone know how to cure the problem???

Hi Mike,

Usually a sign of running rich where unburnt fuel is ignited buy the hot exhaust manifold. I get a lot of popping on overrun with the new system.

Pete

[doynk2]

Are you sure the exhaust has no leaks or holes and the seals are ok?

Any air entering into the exhaust will cause nice big flames and backfire!!!!!

I'm sure there are other factors but im no expert.

[Mikes2esprit1979]

Yes the exhaust is sealed ok.

Must admit its been a while since the carb's were set up.

Might book it in for a tune up next week.

[Evil_Dr_Fish]

Mine does the exact same thing - occasionally after switching off it will give more of a 'pop' than a backfire...

Mine is both running richer than Bill Gates and has a blowing Exhaust flexi-joint-mesh thingy!!!

[Paul C]

Ok, I'm not a G-car, but with the cat out and no silencer i get popping on overrun.

I actually use it with effect when overtaking anyone, i don't change up a gear once

i've overtaken them, i just lift off and show them fire and some angry popping.

Nice Boxter mate, not.

B)

[Jussi]

After we removed cat it backfired even more than before. But it's always nice to watch people to take cover

I have noticed when I park the car in my storage hall there's no backfire, in that case car is going on low rpms for some time.

[iainskea]

Mine backfired on shutdown as you described, but all was fixed when I sealed a leak at the manifold to exhaust triple clamp.

Before you tinker with the mixture flow needles - I would really really be sure there is no air leaks, getting down underneath and feel around (hot!), while someone covers the tail-pipe for a short while.

Once you fiddle with those mixture screws - you then get to read pages of threads on this forum on how to recover the tuning! - Like me!

Iain

[Mikes2esprit1979]

I will double check the exhaust this weekend.

Thanks,I will keep you all posted.

[bigsi]

I will double check the exhaust this weekend.

Thanks,I will keep you all posted.

i would be suprised if the exhuast sections were not leaking.

i have taken my exhaust sytem out all the way beack to the manifold, cleaned the mating surfaces as they looked like crap, on the wastegate to pipe section the one stud/nut was so loose i undid it with my fingers!! the other was useless. from the pipe to the silencer looked just as bad, the aux manifold to the turbo was not seated right, also had one of the bolts missing and it was blowing and sucking air, you could see the gaps!

so i am replacing the wastegate to pipe gasket, aux manifold to turbo gasket, turbo to outlet pipe gasket, got a tube of bosal exhuast compund to seal the pipes to silencer flanges, replace every nut and bolt with new, pressure test the two silencer feed pipes as the boot behind the stainless meshing may have blown a hole if so then replace both pipes also.

then its ready for tuning and timing checks and re-balancing the carbs.

[Mikes2esprit1979]

Well done chaps I had 3 nuts loose on the manifold.

The spring washers had spread out and were not sitting correct.

Replaced the washers, tightened everything up and it seems to be ok.

Thanks to everyone

[1984_lotus_esprit]

Mine does it too when I turn the car off. And sometimes when shifting down from the red line,

my exhaust manifold doesn't have any air or expansion joint leaks. To me its normal, it

been doing this for 20 years.