Merc s500 makes a rattling noise with slight revs then disappears at higher revs .could it be the exhaust?

Question

Merc s500 makes a rattling noise with slight revs then disappears at higher revs .could it be the exhaust?

Answer 1

You "may" have faulty catalyst system based on your description which is common on the Mercedes-Benz and may be covered if you are within the 8yr/80,000 mile warranty period and there is no physical damage to the catalyst. However, it is not conclusive until properly diagnosed. A bent heat shield can cause similar faulty catalyst type sound.

Good luck!

Answer 2

the sounds very likely .

Answer 3

Could be. Maybe an exhaust shackle a bit loose. Also could be water pump wear. Just keep listening, but to be sure, if you hear a noise anywhere on a car, the source will be at the other end!

Check the glove pockets, and anywhere anything loose could rattle around. I had a periodic noise on my Merc once, and it turned out to be the rear of the front door pocket had come adrift, and just rattled at certain revs.