I have very loud engine noise when I start in the morning. After about five minutes, it will quiet down when the engine warms up and the RPM goes down to 900. But still noticibly high. It was like this the I got the car new two months ago. The noise seems to eminate from the Catalytic converter. Outside temp is usually about 45 degrees F.

Have you had your car back to your local dealer? Did they tell you that the noise was normal for this type of Mercedes? There is somewhat a high noise level with 4 cyl. M.B. engines in the C-class. If you start the car in a closed area (garage) the noise can be amplified.

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MERCEDES BENZ MASTER GUILD TECHNICIAN
ASE MASTER TECHNICIAN
27 YEARS M.B. TECH

I also purchased a C230 Komp about two months ago--my impression is the same. Very noisy, especially on cold mornings. Everything I've read indicates this is normal. It's a shame, but a guy in the MB service department told me that when they first got a CLK (with the same engine) on the lot they thought it had an exhaust leak! Rather unrefined, but at least the performance is simillar to the six cylinder at about $5,000 down market. I would be happy to talk further with you.

Sincerely,

Matt

4 cylinders are usually a bit louder. I have a question, do you drive the car daily?? Or every other day?? If I let my '92 400SE sits for couple days, the first 10 min will be very loud(sounds like a Turbo Desiel in Dodge Rams), and then it quiets down.

If it quiets down after the engine warms up, there should be nothing to worry about. Because the car sits over night, and gravity will pull the oil down. When you started the engine, pump will pump the oil back up, and during that time(that's why most tech will tell you that the engine wears the most when starting up), louder sound(valves) is expected.

Anyone has different view?? I am here to learn :)...

Happy Motoring....
Andy Kuo
'92 400SE
71,128 KM

A CLK with a 4 cly supercharged engine???
It is possible that the noise that you are hearing is very normal. The supercharger is engadged on cold start up to perform the AIR injection operaation. It is on the loud side.
Hope this help. Enjoy your new car.

Oops, SLK.

On the post about the 400E/SE being noisy on start-up after sitting, I would get this checked out. This engine has several itms that can cause $$ engine repairs. The timing chain tensioner has been modified & the oil filter check valve redesigned to hold oil for longer periods.

M.B. Doc,

My 400SE won't have noisy sound if I drive the car often(say, every other day), but sometimes, I will just drive my Jeep and 240SX, and leave the car sit for 4 days or so, then the noisy sound would appear. So, do I need to have it check?? What others things do I have to look after??

P.S. I have the timing chain tensioner changed last year, so, I assume I have the modified unit.... :) Thnx for the tips.....

Happy Motoring....
Andy Kuo
'92 400SE