New exhaust system


#1

should a complete new system ($1,000)still be making noise?? It rattles and roars when under 40 mph


#2

Noise? Absolutely not! A new exhaust system, correctly installed, should be absolutely quiet. You car should sound new, its only sounds coming from engine noises under the hood.

Your new system has a warranty, whether 30 days, three months or one year. Use it!


#3

I agree. The vehicle should be as quiet as it was when new. Take it back.


#4

My car is a 1998 Nissan Altima with 117,000 miles and in excellent condition. This same garage has been servicing my car since new and I always trusted him. He keeps telling me it is like a tuning fork with different frequencies and that it will probably never sound like it did when new. OK, but in my mind it should not have that horrible rumble. Like I said, once you get past 40 it purrs like a kitten. I will be taking it back and I thank you for confirming my feelings.


#5

He keeps telling me it is like a tuning fork with different frequencies and that it will probably never sound like it did when new.

Nonsense, my car with almost 400K miles sounds like new. It’s just a matter of finding the problem and fixing it. Maybe the sound isn’t due to the exhausts system, maybe an exhaust manifold or gasket, or maybe it’s another mechanical sound.


#6

Adjustments to the mounting clamps and/or heat shields may make a big difference. If the mechanic added an after market exhaust hanger, it could be transmitting additional noise into the car. The stock hangers are meant to isolate the exhaust from the body to minimize noise.


#7
It's a car not a violin.

#8

Some nissans have a muffler that has a valve in it that will open under different acceleration scenarios to allow the other port on the muffler to open(2 exhaust ports 1 muffler). Don’t know if your muffler was like this but if they didn’t install a factory muffler it could cause a change in sound. Yours sounds more severe but it was the only thing that came to mind that hasn’t already been suggested.