Exhaust leak?, Only after the car is warm? Options

[avidfanjpl]

I keep thinking I have a valve problem, but power is excellent, and there is no smoke.

After the 2.0L engine warms up, I have a flappy sound. I have SSHE's from the 70's and I thought maybe, when the pipes are warm, it makes whatever leak there may be sound worse?

I am taking it in tomorrow to Steve's Independent, but has anyone ever had an exhaust leak that only shows up when the engine is up to temp?

Either that or it is a valve. I checked the lash twice. First time everything was too tight, last time, it was all still to spec. Just cannot figure out the sound.

Thanks!

John

[benalishhero]

I keep thinking I have a valve problem, but power is excellent, and there is no smoke.

After the 2.0L engine warms up, I have a flappy sound. I have SSHE's from the 70's and I thought maybe, when the pipes are warm, it makes whatever leak there may be sound worse?

I am taking it in tomorrow to Steve's Independent, but has anyone ever had an exhaust leak that only shows up when the engine is up to temp?

Either that or it is a valve. I checked the lash twice. First time everything was too tight, last time, it was all still to spec. Just cannot figure out the sound.

Thanks!

John

Perhaps it's a compression leak from a loose head? That would make a flapping sound.

[avidfanjpl]

It comes and goes, only at idle.

And it is not like I don't have all sorts of power.

Taking it in today to see what they say.

Thanks!

J

[avidfanjpl]

Took off the Dansk muffler and the SSHE's today. Cylinder 1 and 3 both had a lot of soot around the exhaust pipes, and the copper gaskets looked compromised, and the nuts were loose. Decided to yank everything.

Need to pull 4 of the 8 exhaust studs and replace them all. 4 came out with the nuts.

Have to place an AA order for my parts, then put new 8X8mm studs in, new copper gaskets and new nuts and muffler gaskets. Maybe that will make the noise disappear?

Took it to my mechanic today to have him listen, and he said exhaust leak right off the bat.

The Heat Exchangers are minty. No holes or leaks. Going to hope for the best on this car.

All the exhaust valves looked typical for unleaded premium gas. Sort of a whitish powder on them, but nothing loose. Guides looked OK. Could still be a partially dropped valve seat, but there is absolutely no loss of power, and the flappy sound only came on after the engine was warm.

Up on jacks for a few weeks to come.

Still stumped, but redoing the exhaust mountings is cheap.

Thanks!

John

[realred914]

Took off the Dansk muffler and the SSHE's today. Cylinder 1 and 3 both had a lot of soot around the exhaust pipes, and the copper gaskets looked compromised, and the nuts were loose. Decided to yank everything.

Need to pull 4 of the 8 exhaust studs and replace them all. 4 came out with the nuts.

Have to place an AA order for my parts, then put new 8X8mm studs in, new copper gaskets and new nuts and muffler gaskets. Maybe that will make the noise disappear?

Took it to my mechanic today to have him listen, and he said exhaust leak right off the bat.

The Heat Exchangers are minty. No holes or leaks. Going to hope for the best on this car.

All the exhaust valves looked typical for unleaded premium gas. Sort of a whitish powder on them, but nothing loose. Guides looked OK. Could still be a partially dropped valve seat, but there is absolutely no loss of power, and the flappy sound only came on after the engine was warm.

Up on jacks for a few weeks to come.

Still stumped, but redoing the exhaust mountings is cheap.

Thanks!

John

to detect a failing valve seat, be sure to keep good records of valve adjustments, keep records of the before and after values, that way you can start to see if one particular valve is going bad 9Say it always is tightening up between adjustments) that would indicate a seat coming out for example, or a stretched valve.


so you replaced the copper gaskets and it still is bad?

did you soften the copper gaskets with heat and slow cool first? (they must be annealed to seal right)

inspect teh tops of the exhaust pipes too, there is not much sealing area on the aftermarktet stainless exchangers, a little dent can cause a leak there.

good luck

[rudedude]

May also check the tops of exhaust pipes to make sure they are in the same plane. I had to file mine so they were flat and now have no leak.

[detoxcowboy]

$$$ says you already found it, and are about to fix it.. anneal (heat to glowing colorations and cool) your copper gaskets prior to install ( your mechanic told me 2 years ago to use a little (just a little layer) assembly paste (also copper colored not sure whats in it, any local Auto Parts) on the assemble as well, #1 on the back side of the gaskets so they hold up monetarily and do not fall or move from the cylinder heads.. #2 on the connecting edges of your HE's..

Being as there was some looseness found that would be your problem.. You may only hear it at idle now or whatever, drive it to Santa Barbara and back and you may hear it all the time by then..

The #1 worst thing you can do on this job is over zealously tighten the exaust studs and strip one into your cylinderheads, either on their own or with the nuts when tightening them..

I use the copper crush nuts as well.. link below Pelican Parts

http://www.pelicanparts.com/cgi-bin/ksearc...2-1-711-954-M58

Also the OEM exhaust studs are available and genuine at CAR PARTS DISCOUNT .com