Exhaust leak

[mike561]

Recently i was told i have an exhaust leak, whitch is probably true because when i step on the gas you can hear a ticking sound comming from around the engine, its not as bad when at idle, but when i rev the engine you can hear it better. the fumes and exhaust still come out the end of the tailpipe though at the back of the car like it should. im just wondering how major would something like this be?

[corning_d3]

It's most likely a blown exhaust manifold gasket or donut gasket. A cracked manifold is also possible. Next time your under the hood, check the manifolds over and look for any blacks spots around the head-to-manifold seal. Any black indicates a leak. Another spot to look would be where the manifold joins the exhaust pipe. An exhaust leak before the O2 sensor could give a false lean reading, and cause the car to run rich..

[capriceowns]

you could have a exhasut manifiold bolt come loose to, which i heard is kind of common cause of crappy Grade-5 bolts. (my car being a victim of this)

it will make like a "popping sound or ticking if your in the cab" I'd check around all the manifolds to see if any came back a little like in the corners etc.

most likely they will be all rusted/really stuck and will just break if you tighter or try to remove the bad one, so if you try to fix a bad bolt if that is whats causing a leak prepare for a lot of work maybe.

[jamestrow]

I am new on this site, glad I found it, appears to be well informed. I have a 1988 Trans Am w/ a Chevy 350 (1987) TBI. Two weeks after purchase it drove me to the Pontiac dealership by request. They recommended another shop so we went there. The shop spent 4 days treating it believing it was a 305, at my final request and plea he finally concluded it was a 350. after this guys expertise and 5 days of changing; the timing chain, distributor shaft, harmonic balancer, adjusting the valves, egr sensor, ecs sensor, spark plugs, computer board, and many other things the car ran worse and my wallet felt equally pained. A few days later I randomly went to another shop and the mechanic noticed immediately it was a 350, listened closely and swapped the map sensor and it was fixed. Amazing. This was done 5 years ago and it has been reliable, 3 three years ago I had the lifters, cams and valves changed. Ok that being the history, here is the present; three months ago I noticed a pulse while driving, meaning a micro go/stop. Not a miss. No audible, just a micro pulse, the common person would not recognize it. Although the gas gauge did. I took the liberty and changed the plugs, rotor, cap and wires, no change. Trouble light time, first code running rich, the visual was the black path beneath the tail pipes standing still, I examined the EGR, ok, I changed the Oxygen sensor, ran better for a couple of days. Then second code, changed the Map sensor and the computer board, ran different, better? No, that is when the idle started to become erratic. Car still running rich. The popping started weeks ago and it is most obvious on a cold start, in Savannah a cold start is around 50 plus. The popping does not go away when warmed, the pulsing is still evident. Just today I got a code 23 and 54, fuel mixture sensor. Never saw that one or two before, never, I don’t trust that error yet. The problem I am up against is each and every time I change something and reset the computer I need to drive 50 miles for the computer to do its readjusting. Back to the popping from the exhaust, my gut feeling says a cylinder or two is misbehaving. That being the case on a cold exhaust it could not be combusting in the pipe chambers near the rear. I pulled the two front plugs and they were tan in color, lean? If I could understand the popping I might be getting closer to the problem, no one around here has a clue and I don’t trust the shops anymore, they ain’t like they were when I was younger….. thanks for your time, James