Is it normal for the exhaust to get louder as the engine gets warmer??? If so, what is the reason for this??

Also i am looking to replace my muffler because i think its too loud.. How do i know if its the central muffler or the rear muffler?

I suppose you might have a cracked or warped exhaust manifold that could get worse as it gets warmer. Or it might be a crack in an exhaust pipe, muffler or joint. It tends to depend on where the noise is coming from in terms of what components to look at.

Have you tried the trick of taking a rag or other object and blocking off the tailpipe? That can quickly reveal an exhaust leak and where its coming from.

Ken300D

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1982 300D at 351K miles
1984 300SD at 217K miles
1987 300D at 370K miles

The muffler gets louder and as a result gets a low frequency vibration that i feel in my seat when the engine gets warmer...

I havent thought of putting rags in the tail pipe... i thought that would hurt the car... should the engine be hot or cold, or does it not matter?

What I'm talking about is just taking a rag and doubling it up and holding it with your hand to block the tailpipe a bit. This won't hurt the car as the exhaust gas will still escape. But any leak anywhere else under the car becomes much louder, while the exhaust out the tailpipe gets muffled by the rag.

It can help you find a hole or crack in an exhaust quickly.

Ken300D

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1982 300D at 351K miles
1984 300SD at 217K miles
1987 300D at 370K miles

That's always seemed to happen with my 300E, even when it was brand new. It now does it with a new OEM exhaust system. I assumed it was the catalytic converter.

For the last 2 weeks my exhaust has been much louder than normal. It is really heard at around 2000 RPM when im putting medium throttle and a normal load.. After 3000 rpm the sound gets higher pitched and i do not notice the exhaust nearly as much.

I was late for a family event so i went a little faster than normal on the highway while driving to my aunts house. When i came off the highway the exhaust was quiet and i barley heard it.. I drove back home after i got done with the family and the next morning i started up the engine again, drove it, when it was warm it started getting loud again.. I dont get it.. Anyone have any idea what could be causing this random exhaust problem??

For the last 2 weeks my exhaust has been much louder than normal. It is really heard at around 2000 RPM when im putting medium throttle and a normal load.. After 3000 rpm the sound gets higher pitched and i do not notice the exhaust nearly as much.

I was late for a family event so i went a little faster than normal on the highway while driving to my aunts house. When i came off the highway the exhaust was quiet and i barley heard it.. I drove back home after i got done with the family and the next morning i started up the engine again, drove it, when it was warm it started getting loud again.. I dont get it.. Anyone have any idea what could be causing this random exhaust problem??

You have an exhaust leak somewhere,

You really should do what Ken is suggesting, you would be able to locate the leak and repair it...

How long do mufflers on 300E's usually last?

Evan

If it were my car I would get underneath the car and inspect the exhaust system, from tail pipe end to exhaust manifold.

Sometimes the beginning of leaks change in sound depending on ambient temps and how long (how much heating) has taken place.

Haasman

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'03 E320 Wagon-Sold
'95 E320 Wagon-Went to Ex
'93 190E 2.6-Wrecked
'91 300E-Went to Ex
'65 911 Coupe (#302580)

Once I get the car back from the body shop I plan on performing the rag over the exhaust tip techinque....

One thing i dont understand is.. If it was a leak somewhere other than the tailpipe why would it be so loud at the tail pipe?? if it was a leak, then at idle it would be quite at the tail pipe correct?

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2001 Mercedes-Benz C320 3.2
1991 Mercedes-Benz 300E 3.0

You may have a problem with your catalytic converter. It sounds like the core is going bad, and as the engine warms it will cause a change of exhaust pitch.

It could also be a bad core in the front resonator.

If you have experienced a change of fuel mileage since hearing the pitch changes, it could indicate a blockage in the exhaust system due to the inner core s blocking the flow of gas.

I performed the Rag Test and it worked perfectly thanks for the tip.. The pipe that goes into the rear of the muffler was rusted through,, so i did a patch kit on the muffler till i find a muffler for really cheap.. Thanks again for the tip

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2001 Mercedes-Benz C320 3.2
1991 Mercedes-Benz 300E 3.0

Evan, you better find that cheap muffler soon. The patch will last about a week.

"How long do mufflers on 300E's usually last?"

Depends upon ambient conditions, and usage patterns, but records for my car indicate the 2nd rear muffler failed at 18 years/210k miles. 2nd center muffler is still holding up.

Not bad, eh? This is for the OE Eberspaecher stuff.

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1986 300E 5-Speed 240k mi.