If you just spent all that time and money to get it fixed then i think you should feep it untill another problem arises and then sell it.

 

Drum roll please....
The verdict is.....CRANK SHAFT SENSOR!!?
What? How can that be?
Dealer is confident that is the problem and not the control unit or software. $700.
Anyone have my noose?

 

$700 for the sensor? that's too much.

if this sensor got problem, there would be times that the car cannot or hard starting.

 

$700 for the sensor...and today the problem resurfaced when accelerating onto a highway. The vehicle now runs, but the backfire continues. Dealer suggests replacing the coils - I already replaced one of the three last week - the others are fine. For $700 they should have been able to narrow the problem. They told me their mechanics aren't allowed by MB to push the accelerator when test driving a vehicle!?!?!?!? How the hell are they gonna know when the problem occurs?

 

it can't be the coil.

during drive test, the situation must be simulated in order to find out the problem.

it's either they are making excuses or got a stinky rules.

 

Hi Fellow Benz owners. I just came across this thread and I've been having the same issue on my '97 C280. I can't help but read through the thread and gasp at the recommendations that the dealer is making. I'm no Mercedes professional but I sometimes wonder who the heck is employed at these dealers. You pay premium dollar for a reason -- bring it in once and fix it. I'm off my soapbox.

I have the same 'backfire' problem exactly as describe. When I step on the gas i get the sputter and delay in pickup along with an occassional backfire. I changed my own plugs to premium Bosche platinums (no gap). Still the same issue. Here are some additional symptoms that may help us solve the problem. The car starts fine and runs smooth. Once the attempt to accelerate triggers the backfire, the car will jerk once I come to slowstop. Engine vibrates frommisfiire at a complete stop.Here's the kicker... I shut off the car and restart which makes the misfire stop. If I try to accelerate too fast and trigger the backfire again, symptoms continue as before.

This is like my old car that had a distributor cap, because the power wasn't making it to one of the plugs. Does my 97 have a distributor cap? I don't think so. If not, what replaced the distribution of charge to the plugs? Is the distribution built into the ignition wire set?

 

Hi I have a 1995 MB C280 that had the same problem that when you would accelerate it seemed that it backfires but not a true backfire. It happened when you really stepped on the gas or when it was really cold. I checked several things myself at home to find out the problem like the MAF and check the spark plugs and the cat and etc. for two days. I was done at that point so I took my car to MB of Westminster in Colorado and found out that one of the coils was going bad but, and this is the biggest thing is that the Supreser (the spark plug wires, rubber peice that attaches to the spark plug) was bad. What was happening is when the supreser gets warm or hot the little spring coil inside starts to not make good conection with the spark plug and cause your backfire problem. So i would replace the supresers and the wires with the coils to get a really good electric spark. The supresers will test good with a meter but will be bad if put in your car and the heat gets to them.