Powerhouse

Hey guys, new to the forum and new to Mercedes in general. About a month ago I picked up my 2004 c320. Now, its beginning to give me problems! Yesterday morning, I get in the car, turn the ignition, and nothing happens. Up until then, every seemed to be working normally. You can put the key in, turn it to get power, and all the power will work. The display says no malfunctions, and no check engine light or anything abnormal. But once you get past the first 2 click, and get to the turn where you actually start the engine, you can turn it and nothing will happen. Not a sound, not even a solenoid click. However, after you turn it, and let go, the engine fan starts up and starts turning, noticeably loud with the door open.
Cut the story short, i bought a new battery, checked all the fuses that were 'engine electronics' and it still does the same thing. Help!!

BigBodyBenzC240

CPS maybe. Crank Positioning Sensor. Sounds like it could be the problem. These engine have too many sensors and all it takes is one for the car not to start. Get it scanned and see if any codes come up but if not I would guess the sensor.

Glyn M Ruck

You are saying that the car does not crank over at all as I understand it - Yes?

Powerhouse

correct, nothing at all happens when you turn the key.

Glyn M Ruck

If so likely 3 possible problems

Starter relay S in front SAM
Starter solenoid
Starter motor itself.

First check relay S

https://mbworld.org/forums/attachmen...eft-engine.pdf

EDIT - hope it's not the EIS - thats expensive.

Also check fuses 31,48,52,53,54,57

Powerhouse

I have checked all those fuses, and they all checked out great.
I removed the relay, and tried to turn the engine over without the relay in. The car continued to do the same old thing, even with the relay out. Does this mean its bad?

Utahkompressor

If you take the ralay out, the engine won't start.
Put a jumper wire on it...if it starts, then the relay is bad.
If it does not start, then the relay is okay and something else is bad.

Glyn M Ruck

+1

Xhale707

Any Update power house?

hew_1999

Hi, where do I put the 'jumper wire'. Are you jumping the connections at relay in the fuse box because I have EXACTLY same problem.
(history): 100K even on odometer but <1k is mine and suddenly yesterday it cranked normal for a split second and stopped. I push started the car in 2nd (got a alt/batt warning light doing that). I've now discovered the engine is bathing in oil (cam seal recall that I have to figure out how to deal with).
Battery is strong. Fuses are all good all around. Tried jumping the starter solenoid below with a screwdriver while tapping with a hammer (think I was doing it correctly by touching the big fat positive + terminal with the other one next to it with the little wire ), got a couple of little sparks (some hard to hear electrical motor whirring noise) and a couple of clicks just like when it stopped working originally. Sounding like a solenoid issue? Maybe there is oil in the starter wires and I'm going to take it apart right now to clean it up with crc electrical motor cleaner.
As a side note, I have a 05 srt-6 too and am now wondering how long before the fun begins and I better check the boards for more info...