MY CLK KNOCKS WHEN I FIRST START IT UP FOR THE DAY. THE KNOCK GOES AWAY ONCE THE CAR IS WARMED UP. DOES ANYONE KNOW WHAT THIS PROBLEM IS?

 

Hi

I have an 03 clk 320 and it also has a knock when cold. I asked the dealer and they said it was normal.

I have tons of electrical problems though. I posted a question wondering if anyone else is.

John

 

It's piston slap. Not a hugely big deal if you don't hotrod it while it's cold. Drive it veryeasy until it's warmed up. A lot of newer cars do this, especially ones with an aluminum block, heads or both.

 

<FONT face="Arial, Helvetica, sans-serif">THANK YOU FOR THE INFO ON THE KNOCKING. I THINK IM GONNA GET RID OF THIS CAR ANYWAY. NO KNOCKS CAN BE GOOD FOR A CAR.</FONT>

 

Piston slap isreal-world engineering at work. I wouldn't dump a late-model car because of it. Extremely tight tolerances on hotter running modern engines isn't desirable.Think of a better reason to get rid of it. </P>

 

Good chance you have delay for oil to reach the top of the engine. Mine does it too, but only very slightly and it goes away in about 20 seconds. Noise is very slight. Did you put in a non-OEM filter? Possible cause. Some filters have a valve to prevent oil draining all the way down, but cheap ones usually don't.

 

THANKS FOR THE INFO ABOUT IT POSSIBLY BEING AN AFTERMARKET OIL FILTER. I HOPE MY CHEAPNESS DIDNT CASUE MAJOR ENGINE PROBLEMS. I HAVE MY OIL CHANGED AT A QUICK LUBE SHOP. I THINK IM GONNA HAVE THE DEALER CHANGE MY OIL NEXT.

 

Oh, and another thing,</P>


Don't change the oil too often, this is a false economy. Use the correct weight oil and original brand filter and only do it when the wrench lights up on the dash, not before. These engines "add up" all the driving experiences depending on your driving style and report to you when to change it. Doing it early and often, especially with an aftermarket filter, is costly short and long term. Mercedes now recommends synthetic oil in all these engines too, so viscosity is not lost over time like mineral oil blends.</P>

 

IM THINKING ABOUT CHANGING THE OIL AT THE DEALERSHIP SOON SO IT HAS THE RIGHT GRADE OF OIL IN IT AND THE ORIGINAL OIL FILTER. THRE KNOCK GOES AWAY AFTER LIKE 3 MINUTES. I HOPE THERES NO REAL DAMAGE TO MY MOTOR. THANKS AGAIN