'07 C230 won't start!! Ideas where to look?
if is the second condition i can help you:
Go to the engine compartment of the car and open the relay boy on the drivers side, ask some one to turn the key and see if a relay clicking sound comes out from any of the relays, if so then the problem is your starter motor carbons more likely, go to the starter motor and with a voltmeeter put the red tip on to the power cable at the starter motor and the black one to GND, then turn the key again and if it measures 12 V DC then for sure the problem is the starter motor, take it away and remove the black cover from it, and youll se the 2 carbons and the housing of them may also be warned out, get some new ones from a bosch dealer resemble and voila!! you are all set now.
BTW im an electro mechanical engineer and i have worked for 4 years in the electronic industry (automotive) so i know what im talking about
You could order the part online and then have an indy put it in or DIY. Like I said though the 07 pump is different so make sure you get the right one.
The Best of Mercedes & AMG
2007's are well known to have premature fuel pump failures. So, it is time to buck up and replace the pump. Pump can be had for ~$200 and if you are very careful and have moderate mechanical skills it is not a bad DIY. I have posted the WIS repair documents and tips on the install. Also wizkid did a great DIY on Installuniversity.com. If you are not comfortable with the task, ~$500 from an indy sounds reasonable. Shop around if need be.
Last edited by johnand; Feb 28, 2012 at 07:28 AM.
whatever they're called. Just like John says, MB suggest
replacing both in case of
failure to one. Dealer also
spoke with MB customer
care and we'll be splitting the
cost of repair. I will be
paying $600 and so will they.
That's better than paying
the whole amount. Here is the million dollar question. What else can go wrong? Is this simply an expensive toy that I can't afford to keep up the repair cost? I've had many cars, trucks, vans, convertibles, etc. Never had to problem like this.
whatever they're called. Just like John says, MB suggest
replacing both in case of
failure to one. Dealer also
spoke with MB customer
care and we'll be splitting the
cost of repair. I will be
paying $600 and so will they.
That's better than paying
the whole amount. Here is the million dollar question. What else can go wrong? Is this simply an expensive toy that I can't afford to keep up the repair cost? I've had many cars, trucks, vans, convertibles, etc. Never had to problem like this.
Tried cranking again. will turn over but not fire up.
have towed to MB dealer.
they run diagnostic. state that fuel pump is bad. tell me it will be 1790 to replace. i read this forum and decide i will do it.
order both parts from partsgeek. install . car still wont fire up. new pump doesnt have the two lead plug it now has 4 leads going into unit into new 4 pin connector. so that male plug is not used. I reassempled old pump and sending unit and plugged the left over plug into the old top thinking maybe a needed to complete a circuit. and the old pump ran well.
so it seems to me that its not the fuel pump or sending unit. the #4 fuse is fine and i swapped out the 20A relay and its all still the same.
what could cause a bad fuel pump on diagnostic and yet not be the fuel pump? do i need to get a dead end plug for the old pump 4 pin connector thats not used now?
I to cant get OBD to clear or read codes. i have to actually tyake my car to the emissions center every month becuiase i cant get rid of check engine light.
i do have a thermostat stuck open and this is causing a crankshaft position sensor fals reading ( learned from another forum page) but dealer says to9 fix that is $3600.
not sure if i have a crank sensor code or not.

Check fuel pressure at the Schrader valve on the front fuel rail. s/b 3.8bar or 55psi while cranking to achieve start.
Check that you have spark.
You need air, fuel & spark at the right time to start.
Already replaced the conductor plate on mine... now it won't start (sometimes)
Already replaced spark plugs,CPS, CRANKPS, fuel relay :/ and still has the same issue. It starts when it wants to.
But im having the same issue with my 07 C230. Cranks but no start. Before it would start after a few attempts but now its been getting worse. (No sound from the fuel pump)
1. It started with sudden shut off. Turned back on at first crank. REPLACED FUEL RELAY
2. Weeks later it had difficulty to start, but it started in the 2nd or 3rd attempt.
3. Check Engine turned on (missfire, position sensor problem on banks a and b)
4. Reseted Engine codes / Replaced Crankshaft position sensor and Camshaft position sensors (all 4)
5. Replaced Spark plugs (all 6) - Same problem / Crank, no start
6. Engine light came back on. Same problem / Crank, difficulty to start
7. Cleaned Position Sensor magnets. It started. turned off. Same problem / Crank no start
8. No check engine light anymore. Same problem / Crank no start.
9. Checked fuel pressure with the proper tool. No pressure. then pressure again. then no pressure. SAME PROBLEM CRANK NO START. Like if the fuel pump works sometimes and sometimes it doesn't. No sound/noise can be heard.
Now we're at the fuel pump. We checked the pressure with the proper tools and as suspected... No pressure.



