We just started experiencing what feels like a problem with the lockup torque converter on our '04 C240. In upshifting into 2, 3 and 4th gear there is an abrupt, harsh jolt and sometimes when decelerating it vibrates like the TC is not disengaging....are there known problems with this model that I can steer the service advisor to (it's under warranty) or should I just let them find it on their own?

__________________
Marty D.

2013 C300 4Matic
1984 BMW 733i
2013 Lincoln MKz

A torque converter if defective will chatter only when engaging or disengaging, you will not feel a chatter/vibration when it’s fully locked up. What you are feeling could be an engine miss fire. If the car is under warrantee , ask for a master inquires for any open campaign letters or recalls. Also ask for any technical bulletins on software up grades.

There was a bulletin on glycol contamination for the 203 chassis, ask if this applies to your car.

I am bumping this to update...the dealer took the car under warranty and did two things:

1) Topped up the ATF.

2) Reset shift adaptation per bulletin.

It's back to silky smooth again. Don't know why it happened, but it was a really jarring ride while it was doing it.

__________________
Marty D.

2013 C300 4Matic
1984 BMW 733i
2013 Lincoln MKz

Glad to hear the car is running smooth again.
As stated by C32AMG, there is a common problem with glycol contamination on those vehicles. I would keep a close eye on the trans. symptoms. The bulletin they performed worked but it generally applies to vehicle with 6k miles or less. At 26K you trans. should be adapted properly already.
I would look inside your door sill and check the production date. If it is 09/2003 or earlier, I would ask for the glycol test to be done. Could save you lots of $$$.

Thanks for the tip...mine was made in 10/03 so it looks like I just got one of the post-glycol models...anyway, the car is leased and the lease expires the same day the warranty does, so it won't cost me a dime to deal with it if it does fail.

I've come to the conclusion that I never want to own any new MB, I just lease them and when the lease is up I return them. Sadly, '04 was the last year with fully paid maintenance so next time I will probably change brands...BMW still pays for all maintenance so I will likely go that route.

Still, I won't give up on my older MBs...it's just the new ones I don't trust.

__________________
Marty D.

2013 C300 4Matic
1984 BMW 733i
2013 Lincoln MKz

I think Audi pays for maintenance as well, not a bad deal. Last I heard they even pay for brake pads and clutches!