Muffler shop said exshaust is running too hot??

[sholzee]

1992 4dr 4.0L automatic 140k miles. The exhaust started sounding load, I looked underneath and the pipe going into the resonator was rotted and coming out of the resonator. The exhaust system was new Feb 01, so it about 15 months. I am in Buffalo, N.Y. tons of road salt. The muffler guys almost did not warrenty it they said excessive heat in the exhaust system caused it, possibly too rich and backfired blowing th pipe out and I need a tune up. I never had the truck backfire on me, milage is same as always about 16mpg, no check engine lights, he says 02 sensor could be bad and not turn on a light. The plugs are at least 4 years old 60k miles, and it does not look like it will be easy to get them out. The truck runs as good as it has for the past 4 years. What should I do?

 

[88vert]

how is your cat

 

[BUCHVILLEMAN]

sounds like that mechanic is full of it. exhaust is made ot handle excessive heat and you knwo your truck is running good. sounds liek cheap pipes. could it have rusted on a weld? it seems that rust start the worst on welds and seams.
get a second opinion. is it stock replacement exhaust or "performance" exhaust? sound sliek you got hosed onthe original job.

 

[Naga Sadow]

If you get it replaced, go to the muffler man. Thats where I got my exhaust installed.

 

[Alec]

My exhaust frequently sees 1500 degrees and more. On a mostly stock truck you shouldn't have any problem with heat, unless your cats start going bad.

 

[sholzee]

Its a stock pipe, they can see in the convertor when changing the muffler, they did not mention that was bad or plugged, plus when they plug it kills driveability and they glow cherry red. I have done business with them before and they seem to be on the up and up.

I did mention that it rusted on the weld and they say the ecessive heat makes the welds rust faster. I guess I will keep an eye on things for now. Unfortunately the rockers, near gas cap, rear tailgate, and front hood are all rusted pretty badly, the common spots for those early years, so it does not make sense putting tons of money in it right now. Thanks !!

 

[BUCHVILLEMAN]

sounds like its a good excuse for straight pipes to me!

 

[mrboyle]

Originally posted by sholzee
I did mention that it rusted on the weld and they say the ecessive heat makes the welds rust faster.

They are full of it! Mufflers and tailpipes rust at the seams because that is where the condensation on the inside and mud, muck and road salt on the outside collect the most. The comment about the resonator collecting fuel is a load too. If your vehicle had a running problem and was dumping too much fuel it would have collected in the muffler, not the resonator. Also, excessive fuel actually will make the exhaust run cooler. Running lean is what causes excessive heat.

 

[drnaline]

Dig this!

Most converters running temp is about 1700 degrees. If it gets over 2000, meltdown. Thats just for the converter though. The rest of the system was not designed to run over 700 degrees. There's probably no fuel coming out of the tail pipe. Its condensation. The more humid the area the more condensation. The fast your system will rust from the inside out. The hotter you keep your exhaust the longer it will last. Road salt is a major issue to the longevity of your exhaust. I've seen brand new factory systems go out in less than two years. I don't care what any one says about stainless either. That stuff wrought too. Pisses me off that every body advertizes stain lasts forever, it don't. I replace it every day.