exhaust sound

[michaeltay31]

hey, i drive a ke70 which is very clean and well looked after. i recently had to get a full stock exhaust put on my car due to getting a defect...

and just recently i have noticed that when my car has warmed up there is a contanst puffing of air from my exhaust..

its sort of hard to explain pretty much when it is idleing in nuetrul the whole car shakes and if i hop out and look at my exhaust about every 2 seconds a big puff of air will come out in between the normal exhaust air there not puffs of black smoke or anything just like a big puff of air.

if this makes sense and anyone else has had this problem i just really wanna know what the problem is wether just age of the car or something else.

cheers.

[DR86TY]

Mine is very similar on idle,

what are you idling at as you may find that bumping the revs up will stop this

[michaeltay31]

it idles at 1000rpm done nothing to the engine so its a stock 4k...yeah i do notice when i do put my foot on the accel a little while in idle it does stop it. but if i dont it will shake and do it. what did u do to urs does it still do it

[Rice86]

exhaust leak?..

lol and you got a defect on a clean well looked after car?...how loud was ur exhaust to get that much attention, no offence just want to know what you had..

[michaeltay31]

Yeah well the body was clean but it was modified...lowered on ma61's with 2" pipe no muffler was good till i got defected.

Defect: Too low, loud, wide and chipped windscreen.

(REGENCY) Then...

Double Defect: Tint to dark, play in steering rack, leaking shock, dimister not working, small crack in break line and no C clip on break line. Yeah.

Now i got stock exhaust and re lowered and Ma61's back on..

[Rice86]

did they pick up on all these on the side of the road...i mean small crack in breakline...
they seriously had nothing better to do that day aye...

[MINIHORSE]

Nah, regency is somewhat of a "filtering system" you go in with a defected car, with the things that the police officer defected you for fixed, then a "Automotive Safety Specialist" goes over your car with a fine tooth comb to point out all the other things you must correct before you can be cleared as roadworthy

I had a peugeot 205 GTi and had 5 defect stickers on my windscreen as the rear brake bias proportioning valve was "faulty" even though i bought it brand new

Oh how i love the SA RTA

[greeneyes]

It is mis-firing.

Mine does it too, every minute or so just sitting there idling it doesn't fire a cylinder. The engine shakes and if I checked the exhaust I'm sure I'd feel it.

Part of having old school points and coils!

[Konakid]

It is mis-firing.

Mine does it too, every minute or so just sitting there idling it doesn't fire a cylinder. The engine shakes and if I checked the exhaust I'm sure I'd feel it.

Part of having old school points and coils!

Mine does this too! my 22re.

Bloody annoying, ive done plugs, leads, dizzy and rotor are in perfect nick as is the battery.

should i replace the coil?

[greeneyes]

I don't know what exactly causes it- Probably slop in the dizzy gears combined with all sorts of other odd wear.. the spark just arrives at the wrong time occasionally.

[michaeltay31]

So is it something i should be worried about or not?

[greeneyes]

I don't- I've had old Datsun 1600s that did the same.

If I felt it when I was driving I suppose I'd hunt it down then, but when the motor is idling it 'over-runs' itself occasionally so the play in the cam chain and the dizzy gears and I dunno what else all moves from being driven on one side to the other.

When you are driving the car under acceleration that never happens, all the moving parts follow the crankshaft until you lift off. When you lift off and decelerate they all move to leading the crank in unison, so it all still works OK.

At idle some parts will get accelerated when a piston comes down, then their inertia will push them on further, and I think that's what causes it. The dizzy gears can rattle back and forth, the timing chain can flick the tension from one side to the other...

[greeneyes]

I don't- I've had old Datsun 1600s that did the same.

If I felt it when I was driving I suppose I'd hunt it down then, but when the motor is idling it 'over-runs' itself occasionally so the play in the cam chain and the dizzy gears and I dunno what else all moves from being driven on one side to the other.

When you are driving the car under acceleration that never happens, all the moving parts follow the crankshaft until you lift off. When you lift off and decelerate they all move to leading the crank in unison, so it all still works OK.

At idle some parts will get accelerated when a piston comes down, then their inertia will push them on further, and I think that's what causes it. The dizzy gears can rattle back and forth, the timing chain can flick the tension from one side to the other...

[michaeltay31]

ok cheers for all the help...was just worried about it but yeah that sort of clears things up thanks.