Poor acceleration on my c240
I have a 2003 c240 and I was involved in a front end collision in December (drunk driver ran head on into my car), anyway the insurance company repaired the car over $7,000; but every since then my car has been poor to accelerate between 20mph to 40mph, but get this; it happens only SOME OF THE TIMES! and there's this "grind down" noise along with a "pull" or "jerk" into gears when shifting. I have taken to the Mercedes dealership twice and each time the transmission test shows negative results, there's no engine light, no leaks under the vehicle, there also seems to be no rhyme or reason when this problem happens, it could be the first start of the day, or minutes into driving, cold temp or hot temp outside, it happens only some of the times, but wouldn't you know it when being look at by a Mercedes tech. it doesn't happen. Also my RPM's doesn't seem to rev up when this occurring not sure if that matters or not.
Can anyone shed some light on what it could possibly be so I can ask the tech. to take a look into it.
Russell@, I was lurking around the internet and I actually saw that the air mass sensor could be faulty so I asked the tech could that be a possibility and the tech said "oh no that's not it...it would have shown up on the scan..." the tech doesn't seem to think that it is accident related, 1st tech says no way its the trans he says if its the trans then problem will continue to occur, 2nd tech says he believes it's the early signs of the trans going bad. I'm going to leave the car overnight and let them try to figure this out, it makes me nervous because I don't have a clue about cars and I don't want to be taken for a ride (no pun intended), I'm working divorce mom.
I figured if you guys gave me a few suggestions to mention; 1. I sound perhaps a "little" bit knowledgeable thus fore saving me from being robbed without a gun. I have been taken advantage of more than once at the mechanic, and I must admit I'm a little bit intimidated by the mechanic.







