Hi all,
Great forum!!!
I need help with my ML320 2000, I have only had the car for about 3 months and it has let me down at least five times so far, however I'm unable to find the problem.
The car would just turn off while I'm driving or when I'm stopped at the traffic lights. All the lights on the dash would come on, as if the ignition is on. When I try to restart the car, it would crank fine but fails to start. If left alone for about 5 - 25 mintues it would start first go. Everytime this happened I called my roadside assistance, but it always starts before or when they arrive, they check a few things and tell me that they can't see anything wrong.
I took the car to Eurotech autos, he plugged into a diagnostics tool and advised that no error has been logged.
Any help is appreciated, any suggestions that I can try to isolate, or diagnose this issue whithout taking it to a dealer....Thank you kindly.

This has just happened again, while driving in 30 degree heat, the car turned off while driving 5 minutes into my journey. Tried restarting car, it cranks ok, but no start, open the bonnet, there's a sensor on the front of the engine on the left hand side (if you're looking from the front of the car). wanted to put water to cool off the front of motor or around where sensor is. unable to find tap. left bonnet open for 2 minutes, closed bonnet and tried restarting again, started first go. Should I attempt to cool off the front of motor with water, or can I get a spray of some sort, what is that sensor on the front of motor?


Thanx.

Try the SEARCH feature on crank "flywheel sensor". That is a commom problem on the M112/113 engines in most 1998 & later cars!

List price is around $100 & takes less than an hour to install.

Fuel pumps can cause tha same results!

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Is this the same part as the crankshaft position sensor (CPS)?? Because I found DIY instrauction on this site and I'm willing to give it a go myself.....



Chadi

Yes it is. It's on the rear of the engine where the engine mates with the tranny on the driver's side. There are 2 types. Be sure to get the correct one.
Joe

I found the related item at my local Merc dealer, They identified the part I need by taking down my VIN Chassis number. The cost is AU$140.00
I will pick it up tomorrow and replace it myself.
If this doesn't solve the problem, I believe I should be looking at replacing the Fuel pump!!!Right?


Thanx.

Most likely, its the crank position sensor. If you suspect a fuel pump later, perform a fuel pressure test. Carefully remove the plastic cover on the engine,
and you'll find a nipple on the fuel injector rail at the right front of the engine.
( looking at the firewall from the front of the vehicle, the nipple will be to your left hand side.) Connect a fuel pressure gauge - 3.5-3.8 bar pressure is the norm.
By the way, if you have an ohm meter and a way to heat the old crank sensor, you can prove that its bad. Hook up the ohm meter to the sensor, max. resistance should be 1400 ohms. Then slowly heat the sensor ( I use a heat gun ) and as the sensor gets hot, if its bad, it will go way over 1400 ohms, or the meter may even read "O L" (or, open.)
(Of course, you try this at your own risk, no responsibility assumed by me in any way whatsoever.)

Well, I replaced the CPS today, let's see how goes it over the next few weeks
Hope that fixed the problem.
Will post a reply if issue occurs again.



Thank you for the valuable information.

Ok, This hasn't worked. Had a few problems again over the weekend. After replacing the CPS, it ran fine for two days.
On the third night, went out for dinner and parked the car after been driving for about 45 minites. came back an hour later and the car cranked ok but wouldn't start. kept trying every 5 minutes, it eventually started after about 20 minutes. Ran fine untill the following night, after driving for about 15 minutes, parked for about 20 minutes and again cranked fine but wouldn't start. AFter 15 minutes started fine and then turned off on the next traffic lights. The cops stopped behind me and were asking my passenger a few questions (if we needed a push). the car again started ok after about 5 minutes only. this was only last night. SO, I'm now hesitant to even drive it.
Any advise please????


Thanx.

I took the car in to the local dealer, they diagnosed that car and informed me that they found a transmission oil leak (Minor), which is allowing a lot of dirt build up in the area where it's leaking, they have seen this issue in the past were it caused the ML to stall and not start back-up. To fix this issue they need to replace an O ring causing the leak. Total cost is $140 inc GST. I hope that fixes my issue. Will keep you posted.

I don't see why a leaky transmission could have caused your stalling problem. The bottom of my transmission is dirty and greasy too.

__________________
98 ML320 (gone but not forgotten)

I agree,
Well they called me today and informed me that the problem re-occured after they changed the O ring, they now suspect something internally within the fuel pump, they need to diagnose further before they decide to replace it. Fuel pump should be covered by my dealer warranty....I hope....Will keep you posted.

Hi,
Well, I picked the car from the dealer on Friday afternoon, after they advised that they found nothing wrong with the fuel pump. They asked me to road test it for the weekend and let them know if there are any more issues. They ran extensive tests on the car and failed to find anything wrong.
I picked up car, drove to my work place (30 minute drive), i parked the car for half an hour, when I returned 30 minutes later, car wouldn't start, kept trying for 30 minutes, every 5 mintues, no go.
I called the dealer, and they asked me to drop the car off to them. the car spent two days with the dealer until I received a call, they advised that the wiring harness connecting to the Engine main control unit appears to be faulty, when the pull the cables the car stalls and won;t start, when they move the cables again, it would start fine. This part is expensive to replace and they need to troubleshoot which particular cable is causing the issue, charging me an hourly rate for the repair. They're unable to provide an ETA or a rough estimate on how long it would take to fix....I'm starting to get frustrated without a car for a whole week now.....Any further Advise out there from anyone???? Thanx.

Electrical problems can be very elusive to track down and it would be very difficult for service to give a time estimate without knowing which component is being replaced.

As frustrating and nerve racking it is I would proceed with the repair, however I would quiz the service manager about the qualifications of the tech who will do the work. I would want a tech who is knowledgeable in the M-Class and is the dealer's best electrical person. Then I would work at some type of guarentee of no, or reduced, cost if the problem is not solved.

Hope they find your problem quickly.

Jim W.

I got my car back yesterday, report from dealer indicates following:
CArried out test via diagnostic machine, no faults stored. Checked fuses and relays, Checked actual valves, cheked fuel pump activation, removed rear seats and checked connection at Fuel pump, Cheked fuel pump current consumption, cheked crank angle sensor signal. Checked continuity of wires to engine control unit, found connections for crank angle sensor loose on control unit causing engine to cut out. Removed most engine wiring harness and replaced wiring for crank sensor. Insulated wiring harness and refitted all parts, carried out extensive road test.

NOT CHEAP at all!!!!