Bluetec No Start
 

2009 E320 Bluetec with 98,000 miles. A few weeks ago, I pressed the Start Button and the engine cranked on and on but didn't start. I pressed the button again and cranking stopped. Pressed the button again and it started normally. Been working fine every time until today. Again, it cranked but didn't start. Stopped the cranking and tried again and it started normally. Is this a known problem? Any ideas? I don't want this to strand me away from home.

You are driving a server room of computers on 4 wheels. You need to see what the computers are seeing during the start sequence. Either get a reader that can talk to the computers or get it to a dealer for diagnosis. $200 diagnosis will be money well spent.

It could be a fuel filter, a fuel injector return circuit stuck open, crank position sensor, fuel pressure relief valve... so many things that you do not want to start replacing if they are not the problem.

The most common problem on that car is the low pressure fuel pump located in the tank. An old-school analog ammeter will be helpful if you have one. Connect it in series and repeatedly crank the engine. When it fails to start it should peg the needle on the meter, otherwise it'll draw about 10A...........

I took the car to the dealer to learn what is causing the random no-start problem. I parked the car in the parking lot and went inside to the service manager. He went out to drive my car into the shop and it wouldn't start for him --- just cranked on and on. He tried a second time and it started as usual. He experienced my exact problem. They had the car for three days and found no reason for the random problem. There were no codes in the computer. I guess I will just have to live with the problem which is okay unless there is a complete failure in the future.

I can't believe the level of incompetence at this dealer. Did they charge you any money for this waste of time?My guess from experience with other computer driven cars and lack of codes is a failing crank sensor.

Find a competent mechanic and get this fixed. Eventually it won't start at all. It's a $17 part.

I remember when electronic ignition replaced points.Alot of us did not trust it,Ford,and GM with modulator problems,and mopar with transistors.
Wished old tech could be brought back,but with cleaner fuels

I don't know about that particular engine, but on the W210 gassers, the crank position sensor could act like that. If car would not start, leave it for 1/2 hr or so and then it would start. Replace CPS and problem goes away. On that diesel this might not apply, but may be worth looking at. A CPS is quite inexpensive

Not starter coils starting to go bad?

If this was a gas powered vehicle I’d agree but I’m still going with the low pressure pump being the culprit.............I’ve seen this happen MANY times......

My W210 with the OM606 had an intermittent crank sensor. Drove me crazy until I figured it out.
http://www.peachparts.com/shopforum/diesel-discussion/393787-w210-can-bus-issues.html

On my W164 with OM642 it gave a code for camshaft sensor trouble
http://www.peachparts.com/shopforum/diesel-discussion/378195-om-642-camshaft-position-sensor-replacement.html

And cranking with no codes? I imagine there would at least be some power loss when it's running.

The diesel W210s are like that too, even though the IP is locked permanently in time with the engine through the timing chain, the system will still throw the red flag for loss of crank position and shut the engine down. I have first hand evidence of this per the thread I linked a few posts above.

If you have a diesel W210 I would proactively replace this sensor, it is almost $100 at the dealer (sorry tjts1 it is not $17). I highly recommend you get a genuine Mercedes from the dealer, read my saga in that thread with a Bosch sensor one digit off from the MB original that refused to work. The car will just die with no warning when it decides to fail on you.

On the OM642 it never died on us (this was when my wife was still driving it) but the performance started degrading and then we got a CE light. The code came back for cam position sensor and I was able to swap it out before it totally failed.

The difference between the OM606 and OM642 sensors is that the OM606 sensor is just a dumb inductive coil and it either works or it doesn’t. The OM642 sensor has internal intelligence and can report back that the performance is degrading.

Both of these though can suffer a failure that is a physical break in an internal connection that can be intermittent at first, is usually temperature related, and can heal back upon cooling. That is the failure mode I experienced on the OM606 sensor.

I am really surprised the OP is not getting any codes for this issue. These cars know if you farted in the seat if you hook them up to Xentry.

If the pump quits while the engine is running it'll throw codes for low rail pressure. I've seen lots of crank no-starts due to faulty pumps with no codes stored. FWIW, the majority of cases I've seen have been on ML/GL's, but since it's so easy to diagnose it only makes sense to check the pump first......

Either way an MB dealer should be able to handle this. I'm really surprised they failed so badly.

The no-start problem is getting worse. In the past, when the engine failed to start, it would start normally on the second try. I drove the car 440 miles yesterday. It failed to start after a 10 minute stop at a rest area. It took three tries before it started. This happened many times during the day. If the car sat for several hours, it started normally. If I tried to restart it immediately after turning it off, it took three tries to make it go. I don't know what is magic about the third try. Running performance seems to be OK. Lots of power, no missing, 36 mpg running at 70 mph. it is going back to the dealer for another attempt. (Sometimes a random problem has to deteriorate to the point where it becomes a routine problem)