Hi, Folks,

I have a 2002 E320 with 56,000 miles on the clock. Beginning a few weeks ago, I noticed a rattling sound on cold start ups that faded almost away after about one minute of run time. I recharged my air conditioner thinking that the noise might be coming from a failing compressor. The noise did not go away and seems to have become more pronounced over the last week or so.

The local dealer says that I have some "tappet noise", that some of these cars get it and some don't and that it is not bad enough to fix. My questions for the forum are:

1. Could i really be experiencing tappet noise on a $50,000 automobile with only 56,000 miles in it?

2. If so, is this a common problem with this engine?

3. What could be causing it?

4. Should i have it fixed now before it gets worse?

5. What recource do I haved with Mercedes? This car has just come of warranty.

please let me know your thoughts and advice.

Thanks,

Steve

Number 1 cause of engines noises on any engine is lack of oil changes..if you are following the FSS on that car & only changing the oil every 12K-15K miles then THAT is the most likely problem..oil isn't that good!

Start out with a can of flush & have the oil changed..sludge is common on FSS engines!

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
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Steve, are you using Mobil 1 0W40 in your engine? How often do you change the oil and filter?

__________________
Fred Hoelzle

My daughter's CLK320 is doing the same thing. I diagnosed it to be the cat - the ceramic coming apart inside. The independent tech who works on the car told me this is very common, and a known problem on these cars, and since it's emission-related, Mercedes will replace the cats under warranty - even after the vehicle warranty has expired. The cats are right under the cylinder heads, so it sounds a lot like a valve-related noise.

Thanks, MB Doc, Fred & Harry.

I've had 10,000 mile oil changes done by the dealer using Synthetic 0-W40. My usage is almost entirely on the highway at 70 mph. The car is in the shop now for another oil change. I hope things are improved. The cat issue is intriguing. I will call the dealer and ask him to check.

Thanks again for your support. I hope to hear more good advice from the forum.

Cheers,

Steve

Are you SURE it's a lifter noise? I see lots of 112 and 113 engines with carbon knock issues. The colder the weather, the worse the noise. Before you spend big money why don't you run a few tankfuls of gas with Techron, or better yet, try GM Top Engine Cleaner. The latter will require removal of the spark plugs.