Date registered: Jun 2011
Vehicle: 2002 Mercedes-Benz C240 Classic Edition
Location: Kelowna, B.C. Canada
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
Random Engine Stall, decreasing idle too...
I have a 2002 C240 and I've recently had an issue while driving. I've read similar posts to this one but someone always writes their own issues that are different from this matter.
Basically what happens is while driving, no matter what speed (fast or slow) and whether I'm accelerating or just sitting at idle. It feels like the engine slowly begins to lose power, sputters and finally stalls. There are never any notifications on the dash or any signs of it beginning to fail. This typically happens when I'm slowing down at an intersection or just driving slower in traffic. I've noticed that once I'm stopped and the engine begins to lose power and begins to sputter that the rpm's are still idling normally at around 50 until the engine turns off and then the idle goes down with it until it's gone. There was a time when the stall happened that I received a message on the dash saying check alternator/battery, but I replaced the battery the day before and I know it can't be the alternator because the car just wouldn't start after. Also I can start the car and idle it in park without an problem, and have it sit in neutral as well without anything.
The funny part is that I can just turn the ignition off and turn it back on and the car starts up just fine. No problems for the next 20 meters and then the problem occurs again. I've noticed it does this mostly after a long drive, say 2-3 hours of driving with occasional stops. Recently however this has been happening just as I drive into town (15 mins).
I've had the car accidentally run out of fuel once before and it sort of feels like the same thing however I've never let it go past 1/4 fuel since then.
There are similar posts explaining the symptoms and various cures like Mass Air Flow Sensor, Idle Air Control/valve, fuel pressure regulator, and a crankshaft positioning sensor however I was told that the Idle Air control valve is working fine, and the CPS wouldn't work after it has failed. I'm not sure if the mass air flow sensor would be the problem since it feels more like the engine just isn't getting the fuel it needs but I may be wrong.
I did try to check the fuel pressure while it sat in park and idling and it seems like nothing was wrong until randomly I saw the pressure go from 50 to 30 in a matter of 6-8 seconds and the pressure shot back up to 50 again.. My mechanic said this is abnormal and should not happen in any case which is why I'm leaning towards a new Fuel Pressure Regulator.
I was hoping someone would have a solid idea of what may be the problem may be or give some insight. Is there a way to install a FPR without buying the whole fuel pump, regulator, and filter unit? (I'm almost positive it comes all in one bundle that won't disassemble)
I appreciate any help!