W163 ML270 Engine Problem

[freddiea]

Hi,

I am desperate for some help! Last Monday my 03 ML270's engine simply stopped when i stopped at a roundabout. It re-started after a couple of mins and the the sam thing happened at the next junction a couple of miles away. RAC attended but as it started they just followed me home (about 10 miles). No problems so they left me to it.

On the Tuesday, I drove to work (33 miles) without incident. Left work did a 15 mile journey without incident. Set off for home, covered about 10 miles and it all cut off again at a roundabout. This time it would not re start.

Again RAC attended and arranged a truck to take it to the garage. by the time the truck arrived it started so i followed the truck.

2 Miles don the road it cut out while accelerating. Put on back of truck and delivered to PCS an independant MB specialist.

It started fin for them the following morning, but broke down when taken for a drive and would not re-start. They took the Star Diagnostic kit out with them and followed through until it told them to press F5 when cranking the engine, it started immediately.

There were no faults stored in the ECU!

Since then they have taken it out for several test frives without problems.

So today i collected the car but am slightly worried as we are off to Devon on Friday and would like to make the journey without incident!

Any suggestions or similar experiences would be appreciated.

Manu thanks!

 

[panason1c]

The crankshaft position sensor (cps) is known to cause problems as you have described, cheap and easy to fit....

 

[freddiea]

Any more detail?

Would this show any waring lights (none diplayed at the min) or any other symptons?

Is there any way of testing the CPS?

Thanks....

 

[BlackC55]

Yes. When cranked the rpm signal is lost on the Star display when it faults. Its just difficult to get it to fault!!

I would be steering towards the rail pressure monitor as the problem.

 

[panason1c]

Any more detail?

Would this show any waring lights (none diplayed at the min) or any other symptons?

Is there any way of testing the CPS?

Thanks....

As far as i am aware a faulty cps will not throw up any fault code, nor is there any way of testing it....might be worth replacing it as it is not mega exbenzive.

 

[stringbag]

My CPS went a few months ago with exactly the same symptoms as you have got - it does not show up as a logged fault on the ECU, the engine just stops when it fails. Get it changed, especially if you are off on holiday!

 

[freddiea]

Thanks everyone for your comments,

Passed on the PCS and they are getting me a CPS ordered A.S.A.P.

In the mean time, any further suggestions or comments would be great - also, where is the CPS located and any idea of Part Number - Just in case the garage is slow i may be able to do it myself?

Once again, many thanks!

 

[BenzComander]

Would agree, had a Saab 9000 that had the same symptoms, and turned out to be the CPS.

 

[panason1c]

It sits just above the starter motor, held by a single bolt and is a very easy diy job........

 

[freddiea]

Thanks again everyone,

I will let PCS Change the sensor so long as they get it tomorrow or Wednesday - In the mean time if anyone can think of anything else that may be the cause it would be great to know, just in case!

Cheers