Strange noise from exhaust

[Steve H Junior Member Find all posts View Profile Close Steve H]

gone

[Wil Senior Member Find all posts View Profile Close Wil]

maybe you parked on a snake

[Steve M Addicted PP Member Find all posts View Profile Close Steve M]

Fumey is normal when cold, like having the choke on. 18 per 100 is getting up there but depends on what your vehicle has added, and exactly how much start and stopping do you do. When you say way over, by how much ?? up near the 30's you have a problem, just over to mids still a tad high but again how much weight you towing, how much on board and again what mods you running....the hissing I have no idea lol. Certainly have never heard it from mine..Cheers Steve

[Guest Close Guest]

Is it a Grande?

[Steve H Junior Member Find all posts View Profile Close Steve H]

Is it a Grande?

all ok now

[mcfqn Junior Member Find all posts View Profile Close mcfqn]

do you have poly air bags in the rear springs? thinking it might be an occasional air leak rather than exhaust???

[Steve H Junior Member Find all posts View Profile Close Steve H]

do you have poly air bags in the rear springs? thinking it might be an occasional air leak rather than exhaust???

ok

[Steve H Junior Member Find all posts View Profile Close Steve H]

Also Im not using any oil or water, not getting hot and its running absolutely perfect. Can hardly feel it idle when its on 98 fuel.

[Hass Lurker Find all posts View Profile Close Hass]

any chance it is air conditioning condensate leaking onto the exhaust or some fluid flashing off the exhaust? I would imaging you would hear that through the tail pipe

[Fred63 Advanced Member Find all posts View Profile Close Fred63]

Exhaust valve leaking?
Only makes the noise when that cylinder is under compression when you stop.

[Steve H Junior Member Find all posts View Profile Close Steve H]

Exhaust valve leaking?
Only makes the noise when that cylinder is under compression when you stop.

Yes, leaking valve was one of my thoughts but it is running so smooth, I honestly have to look at the tacho to see if its running sometimes. Thought a leaking valve would run a bit rough?

[Steve H Junior Member Find all posts View Profile Close Steve H]

any chance it is air conditioning condensate leaking onto the exhaust or some fluid flashing off the exhaust? I would imaging you would hear that through the tail pipe

is ok

[mcfqn Junior Member Find all posts View Profile Close mcfqn]

You've really got us scratching our heads with this one!!

Thinking logically here and by process of elimination, between the tail pipe and exhaust manifold, what equipment is tapped into the exhaust? O2 sensors, AFR sensors - can either of these make a noise?

Exhaust gas leak through an open valve like Fred said?

Vacuum or accumulated pressure inside the engine oil circuit that is bleeding off slowly?

What else is pressurised? A/C but that's not connected or near the exhaust. Transmission oil circuit? Prob not.

I have no more ideas!

[Steve H Junior Member Find all posts View Profile Close Steve H]

I have no more ideas![/QUOTE]
running great