khaniboy459

Hi all,

Any guidance on the following problem would be appreciated,

I have a 2008 C320 CDI with the OM642 engine (UK/EU model?) with 107,000 miles on the clock. Anyway, after a long drive yesterday i was on reserve, i parked up on the street which had quite a heavy right bank (25ish degrees) so the car was tilted towards the right a fair bit if that makes sense. Now, I've noticed whenever I'm parked with the car banking to the right, the fuel level drops by about 1/10 of the gauge, I'm guessing the fuel level sensor is on the left side of the tank so it doesn't sense any fuel, but I'm aware of this because the opposite happens when I'm parked to a left bank, so its not a concern. Turned the car off, got out and went about my evening. Now, here's where it gets funny, i come back after a couple hours and i notice the car wont unlock, at first i thought maybe the battery remote has died, but eventually it unlocked when i held the key close to the driver door, and i know the remote battery isn't weak because i usually triple check to make sure the car is locked when I've walked quite far away after I've arrived somewhere, usually 30-40 meters away and it works fine. Next, i go to start the car and notice that the fuel needle didn't even move at all, i know i was low on fuel but the reserve light had only just come on so there was defo fuel in there, and regardless of the right bank, it should move at least a little bit, also, the orange fuel level light wasn't on, nor was the car showing any range, it just said "range:---". it was almost like the car knew there was fuel in the car but the fuel related systems were completely dead. So i drive to the petrol station and put in a full tank, but still nothing, the needle is still completely dead, stuck at the bottom and the range still shows "range:---". Now, I'm driving back home and i turn the heated seat on, i notice the seat is heating up like usual, but the 3-stage, red heat light wasn't working for either driver or passenger seat, but both are warming up like normal. I'm yet to discover any other funny faults as this only happened last night, but i have no idea what is going on. I'm a mechanical engineer so I'm quite hands on and understand mechanical and technical systems, but electronically i don't have a scooby as to what's going on. These three problems are definitely related to each other because none of them have ever happened before, and the chances of them happening at the exact same time and it all being unrelated don't any sense.

Any advice would be appreciated,
Many thanks.

TimC300

My parking area is on a slight slant and I back in, so the front is lower than the rear and I had noticed the fuel level reads lower parking this way. One time i got in and the low fuel light immediately came on, so I made it a habit of getting gas before getting home if low.

I would hook up my Mercedes obd scanner and see if there are any faults.

The fuel range may just reset on its own after some driving. Or could be a faulty fuel sender unit. I would drive around, fill up again and see what happens. A scan of the car may help diagnose.

Was it raining out? Thinking if it was raining and the way the car was parked slanted maybe water got in somewhere it shouldn't. Im purely speculating.

khaniboy459

I try not to let the fuel level get too low before i refuel, I know its not great for the fuel filter, fuel rails etc.

I did hook up my OBD and scanned for any faults on the ECU via Torque Pro, but ECU didn't have any faults stored, maybe a MB specific tool would be helpful in picking up any hidden codes.

No, it wasn't raining at the time, and it hasn't been for a few days now.

I'm more inclined to think its an electrical or software glitch somewhere, purely because 3 issues all started at the exact same time. Considering I've had the car for 2 years, clocked about 30k miles and it's never given me a single fault, seems very unlikely that 3 things go wrong all of a sudden at the EXACT same time.