2005 CDI - hot start problem
 

Hi all. My 2005 E320 CDI would crank but not start when hot. Sometimes it would go for a good 10 seconds but never catch, other times it would crank for just a couple seconds, and sort of "stall" out. It threw the code P0336 (Crankshaft Position Sensor) so I replaced the sensor with a Bosch part. The code did not come back but a few days later the problem returned. I replaced the sensor again thinking I may have gotten a bad part. Things were fine for about 3 weeks but the problem is back yet again. No codes this time. Cold starts are no problem, nearly every time the engine is warm it takes multiple attempts to get it to start -- in many cases nearly running out the battery. On occasion when this happens, I get the "Coolant - Visit Workshop" message on the dash, but again there's no code, and no CEL. Any ideas?

How does your coolant level look?

Fair question! Level is spot-on.

I had a similar problem with my 2009 E320 Bluetec. There is a long thread telling my story and solution. Search DDAY for Bluetec no start.

Yikes! Reading that thread doesn't make me happy to have this issue. I only have a basic code reader so I should probably take the car to a shop with more sophisticated technology and see if they can diagnose.

Good idea to have the codes searched. However, my car never showed any codes. During all the problems i had there was only one clue. I have two identical cars, one is a 2008 model and the other is a 2009 model, and the problem car seemed to crank over just a little slower than the other car. That is why i replaced the starter. I still don't know if the starter was the problem. If i would of had only one car i probably could not of detected the slower cranking speed since the difference in cranking speeds was so minor.

That's what really worries me! Thanks for pointing me to your thread.

You could buy yourself a Foxwell code reader for this and future events. It will also allow you to read the current draw when cranking which maybe useful?

Thanks for the suggestion. Is there a model that's cheaper than the NT520 that anyone's using and would recommend, or is that the way to go?

NT520 retails for about the same cost as the dealer would charge for an hour's work to read your codes.

NH82W123-there's an article in "the Star",Jan-Feb 2014, p70. It covers the crankshaft position sensor. I changed mine as the article said they go bad over time. A way to check is to pour water on the sensor. It cools it and the vehicle may start. It's on the fire wall a little toward the driver. Very hard to get to from underneath but only one bolt (I think) and an electrical connection. It's very difficult to get your hands up there but doable. The article says it sometimes does not show a code. steve

Thanks, Steve. I've replaced the crankshaft position sensor twice so I'm thinking there's something else going on.

When i fixed my no start problem i did two things at the same time so i don't know which one solved the problem. I replaced the starter. But to get to the starter it is necessary to remove a section of the exhaust system. There were three wires going to some sort of sensors in the exhaust system that had to be removed. I unplugged connectors in the three wires and then plugged them in again after the exhaust system was replaced. I suspect there was a faulty connection in one of those three wire connectors and i fixed it by disconnecting and reconnecting them. if i have this problem in the future i will first unplug and the reconnect every device in that exhaust system.

solved
 

To close the loop here... I eventually bought a Foxwell NT530 after it got to the point that every hot restart was a struggle. Fault code: 2043 "camshaft hall effect sensor/no signal". I ordered a new Hella camshaft position sensor (odd, it seems Bosch does not make this part) and installed it today. Cleared the codes, got the car up to 82C, and tried the hot restart. Fired right up, and the code did not return. Sensor replacement was dead easy, though I did snap off the brittle snap connector on the electrical plug despite great care. So all that's holding the connection is the friction of the fitting itself. I'll check it in a few hundred miles to ensure it's still tight.