Car is not starting- 2nd time around
Ill attempt to start the car and nothing happens. Only the fan comes on really loud.

The first time i had this problem it just fixed on its own. A couple of days later it just started. But now its been about 4 days and I still can't get it to start.

Finally yesterday she started, (6 days later). All I did was I unplugged the battery two nights before and plugged it back up and still didn't start. But randomly it started a day later. I figured it wasn't the battery and it was water damage in the fuse box where the ECU is. This problem only occurs when it rains.

It worked this morning, but its not starting up again right now. I don't know what to do, i had to leave it at work, and i really don't want to tow it. Leaving it there is not such a great idea either.

Does anyone know where i should be trying to find the problem. I am trying to narrow it down. Thanks for any help, I could use it.

What HAPPENS:
When I put the key in the ignition all the lights turn on, but when i turn to start the car nothing happens at all. The only thing that happens is you will start to hear the fan spin. Then it will just continue to run at full blast. When i move away from the start position the fan turns off.

Thanks for any help.

 

How long is a piece of string ???? CPS maybe. Have the crankshaft position sensor checked.

 

This happened to my w203 last week and it was the fuel pump, after the replacement the car was okay again.

 

Yep - can be seized fuel pump, low pressure from fuel pump. clogged fuel filter

 

why does this only happen when it rains, i cleared all the drainage systems of all the leaves. There was nasty build up, so Crackshaft sensor needs to be checked. I just replaced my fuel pump and filter less than a year ago.

 

Hang on there - sorry it was early hours of the morning here and I did not read your first post properly.

You say nothing happens - Does that mean the car does not crank over ??? i.e the starter motor is not operational? I'm going to take it fore granted that this is what you mean - correct me if wrong.

- Firstly - you can't go disconecting & reconnecting the battery on these cars without a quiescent power device to keep the cars systems powered up or all of the onboard modules with volatile memory will loose their settings & need to be re synched. You can also blow the SAMs on the vehicle

- We can probably forget about pump & filter - they are new

- Your engine fan should not run - you say the "fan runs really loud" do you mean the engine fan or the ventilation fan? If the engine fan is running then either someone has hot wired it or the temp sender unit for the fan is shot.

- I can't say why it only happens when it rains but logic would dictate that water is effecting something

- If it's not cranking & you are happy in your own mind that it is not the ignition switch then it is likely a solenoid downstream of the ignition switch or the starter mototor itself. How well is this car maintained? When I hear about leaves clogging up things I wonder. I would make sure everything in the fuse box ECU area is bone dry - use a hair dryer if need be (gently!!!! don't heat up things excessively)

- Right - is the car throwing up any codes - any warnings on the display? Is the CEL light coming on?

- It would probably be a good idea to borrow or buy a 70 buck OBDII/CAN reader from Kragens or similar & check for codes & see what they are.

- If you don't want to do this then you are going to have to get the car on a STAR DAS at the dealer to see what is going on & they can tell you if you blown anything and resynch everything

Let us know & good luck

 

Thanks for the detailed reply, it has really given me something to go off on.

The engine fan is what goes on really loud, i went through the fuse box under the hood where the ECU is located, and it was wet. I blow dried it for a while not letting it get too hot, i did it in direct sunlight so the sun helped out a lot.

It is bone dry now, but there was a little water that enter the ECU, you can see the water deposits. I keep the car pretty well maintained, but i never noticed that it was clogged because it was a nasty build up of a little leaves that aren't noticeable unless you take a coat hanger and run it through the area.

Yes you were right in taking it for granted that the car does not crank over. It feels like i am just moving the key to position one, but you hear the fan turn on. It's like it thinks it is overheating, and that's is why i thought it was the ECU.

There is no CELs on, and i had a friend bring over his scanner to scan it. It was way better than an OBD II reader. It said everything about the car, and I was so surprised. But the thing was as soon as he brought the scanner she started up. And then the next day she gave out again.

 

Kareemo,
You have got to stop the electrics & electronics from getting wet. Just small amounts of corrosion can cause havoc. Clean everything that has got wet with electrical switch cleaner & get your friend back with his scanner.

Make sure you get switch cleaner that is water displacing. The switch cleaner can't repair corrosion damage but it can at least stop it from going further.

 

I cleaned her all up, and I am still trying to find out how it is getting wet in there, but luckily I got a week or two before it starts to rain, and i won't let get wet until i find out exactly how its leaking in there.

My friend said he can't make it until tuesday, so i am hoping that she won't give us too much of a hassle, by acting like she is ok when he comes. Last time she started and didn't give us any codes. Im hoping it will be a little different. Thanks for the help guys, ill keep you posted.

Tell you if I make any progress. If anyone else has any suggestions, feel free to tell me. I feel awkward not being able to driver her.

 

My friend dropped by and we tested the car. No codes, and i mean nothing.
Everything checked out.

So now i am back to square one with nothing to go off on. So I don't know what else to do.

 

alright guys so i think i got the starting done, and it was the ecu.

Now i have 3 codes.

P0305 Cylinder 5 Misfire detected, it says it twice
p0306 Cylinder 6 Misfire detected.

I think its the coils, but i dont know which coil is which.

 

OK - you need to do this by a process of elimination. Mark the coils & the switch the around with another cylinder. If the misfire code changes cylinder you know which coil or wires need replacing. Might just be wires. Do that & report

 

Kareemo,
Read the last half of this thread. I talked Kris through a similar fix. Ignore all the early stuff when we thought it was a fuel problem. It was a wire problem. Also check your plugs.

https://mbworld.org/forums/c-class-w...ine-light.html

 

Glyn N Ruck, thanks a lot for the speedy response. I found what the problem was, and it was indeed the wires. I only replaced the two, but i am going to replace the rest next time i service it, because they are pretty expensive just for the wires. Luckily gas has dropped a lot, and I can put aside more cash for the service and wires.

Thanks once again, your post was a great help!

 

oh i forgot to mention, i am getting the malfunction on the computer for the SRS. I believe it is a sensor that is not worth replacing, since I hardly ever have passengers. Is there anyway i can just bypass it so that the computer wont say 1 malfunction.

Its not such a big deal, but its just kind of annoying always seeing that as the first thing when the car starts.

 

Always a pleasure to help. I don't know how to sort your SRS code. Ask the dealer how much to fix when you service. It might be worth doing for safety reasons when you do have a passenger - Good luck!