Every time the car sits for more that 5 hours, it will have a rattle or tap on start. After maybe 15 seconds it is gone...

I searched the forum and saw that it could be the cats or the heat shield. Any suggestions?

It is quite while driving and accelerating, but it just has a rattle after a long period of time.

The car has 90k on the clock, but when I bought it from the stearlership it had an engine/drivetrain warranty for six months.

Also, was the emmisions recall was for 8 years or 80,000miles?

This may sound stupid, but if the car is under 8 years old and has over 80k i am still paying out of pocket, right?

 

8 years OR 80,000 miles and MB USA will not pay for it. Cats will rattle on start up if the center core has separated from the outer shell. However, they’ll also rattle just off idle. If it *only* happens after the car has been sitting for five or more hours, then it sounds to me like the lifters are bleeding down and they may be a little bit slow building oil pressure back up. What kind of oil do you use?

 

I was woried that it may be the lifters.... I was just hoping it was the cats instead.

I have to check with the dealership on the oil... I just bought the car 2 months ago, and maybe put 700 miles on it.

The oil has not moved one bit on the stick, and the car drives great.

 

Could this be a bad engine mount also? I have it down to 3 possible things

1. Lifters.... A possible valve adjustment?....Covered by warenty

2. Engine mounts..... Covered by warenty

3. Cats.... Not covered and $$$$

I hope it is the mounts. I do not want a huge job like the lifters having to be done.

 

No, what you've described has nothing to do with motor mounts. They don't rattle for 15 seconds after starting a car. Motor mounts themselves don't rattle at all.

You've got a warrantee on a Mercedes Benz that covers a valve adjustment? Here's an M113 without the valve cover. You'll note the rockers don't have screw adjusters and lock nuts. That leaves shims. The WIS doesn't give any indication that the valves can be adjusted by shims under buckets. The EPC doesn't show any part numbers for shims or buckets. If there is nothing to adjust, that may point to rocker arm wear, cam wear, or bad lifters. Worn cams and rockers don't get better after 15 seconds. Lifters however, will pump up in 15 seconds. It sounds like the lifters to me. However, if I were a dealer mechanic looking at the car, I'd say, "if it's quiet after 15 seconds, it's within spec."



You said the car has a six month warantee, so it doesn't sound like you have a CPO car. If it's not a CPO, I have no idea what kind of warrantee you were sold and what it covers. If it is a CPO, motor mounts are covered. Lifters are covered too, but based on you description, I have doubts that MB USA is going to eat the bill.