[Sito]

Hi all

Loved this site its helped me with so may things before, CEL due to MAF, reprogramming keys, etc. Although I seem to have another I was hoping you guys could help me out with.

2001 ML320 with 76,000MI

My 2001 ML320 occasionally won't start. The starter will go and the car seems to turn over, but won't start. I'll keep trying a few times but nothing, then I'll wait a few minutes then try again and it'll start. Its not every time I start the car it seems to be random. Also theres briefly a CEL after I finally start it, but if I shut off the car and start it again it'll go away. Also once I start the car i can turn it off and on as many times as I want to without any problems. I've done some digging and some things point to a Crankshaft Position Sensor CPS, but I'm not exactly sure if thats the problem. I have yet to change the spark plugs so I was thinking it could be bad ignition? I've also heard of clogged injectors. I'm not really sure what to think. Any ideas?


Also I wanted to add I don't have any stalling or dieing problems on the road once the car is started and going.
Thanks!

 

[43sqd]

This is a classic Crank Pos. Sensor problem. The CEL is not illuminated with this problem, but in all probability there is a code stored. So the first step is to hook up a scanner and see if there is a code(s) stored. Don't start replacing spark plugs to remedy this problem

 

[Sito]

I was thinking of just hooking the car up to a obdII reader and seeing if anything came up. if it is a CPS are they all located in different areas for the v6 and v8 models? If I remember correctly the CPS for the v6 is a PITA to get to isn't it? And does anyone have any places where I can pickup a CPS?

 

[43sqd]

I was thinking of just hooking the car up to a obdII reader and seeing if anything came up. if it is a CPS are they all located in different areas for the v6 and v8 models? If I remember correctly the CPS for the v6 is a PITA to get to isn't it? And does anyone have any places where I can pickup a CPS?

The CKP sensor on both 6 & 8 cyl. is located in the same position,top rear of the engine where it meets the trans, more towards the drivers side. You will need a #8 female Torx socket.

There are four sensors listed, depending on your VIN #, so a word to the wise, go to the dealer and purchase one. They have them in stock.

 

[geordie]

I had a similar issue with similar symptoms

I changed out the CPS - with help from the great people here.
Note you'll need a 1/4" drive E8 socket (there's not enough clearance to get a 3/8" drive socket in there).
It turns out that my starting problem was related to a loose connection in the positive cable connected to the battery.
I'd reccomend rechecking all of your connections as a first step. It might save you some time and money.

 

[techyiam]

I changed out the CPS - with help from the great people here.
Note you'll need a 1/4" drive E8 socket (there's not enough clearance to get a 3/8" drive socket in there).
It turns out that my starting problem was related to a loose connection in the positive cable connected to the battery.
I'd reccomend rechecking all of your connections as a first step. It might save you some time and money.

Bad connections are tough buggers to find.

Sometimes a simple battery voltage check is worth the effort to include in the diagnostic process. Just place the volt meter probes on the battery terminals (not the connectors on the battery cables) and monitor the battery voltage during the starting/cranking cycle.

Now that your car is operating normally, it would be a good time to record those readings. Then in time of trouble, you know what they should be. If the voltage is too high, then you have potential connection problem or a malfunctioning device, and if too low, you have a drained/bad battery. Of course there is a range to consider during a cold winter and the hot summer since the starter motor will have to work harder turning the engine over when the oil is more viscous in the cold winter.

Should you be able to make the measurements, it would be great if you could share your readings with the board.

 

[Sito]

Just wanted to let all of you guys know, Got a new CPS in. Yanked out the old one and plugged in the new one, that was 3 weeks ago, no problems starting at all since then. The sensor was only $58 shipped too, MB wanted $120 just for the part and another $100 for labor.......

Thanks a ton guys!

 

[Solidjake]

You're welcome. it sucks that such a stupid sensor brings hell into starting the ML's. Good job with the fix and enjoy the truck.

 

[FAR888]

Ditto Sito

Just wanted to let all of you guys know, Got a new CPS in. Yanked out the old one and plugged in the new one, that was 3 weeks ago, no problems starting at all since then. The sensor was only $58 shipped too, MB wanted $120 just for the part and another $100 for labor.......

Thanks a ton guys!

Thanks for posting back your solution Sito.

My ML has developed a similar problem too - It most often manifests itself when the engine has run a bit (ie warm/hot) and you switch off and try to start again and nothing. It starts on the second attempt.

It never happens when the engine is cold.

I am convinced too that it is my CPS.

I note you bought yours for $58! Could you kindly let me know where you bought it?

Thanks!

 

[pcy]

FAR888, if you have a OBD-II code reader, why don't you hook it up and read the codes. There may well be a code stored in the memory.

 

[FAR888]

FAR888, if you have a OBD-II code reader, why don't you hook it up and read the codes. There may well be a code stored in the memory.

Hey pcy!

That would be a great idea if I had had the good sense to have bought one when I bought the truck in the US last summer - As you can see from my profile, I live in West Africa and can't purchase one over here.

I am currently making plans for some friends over there in the US to get me a portable one.

Any ideas on good portable OBDII scanners? Do you have one? What's your view on those made by Equus?

Sorry about the barrage of questions!

Thanks!:thumbsup:

 

[mlfun]

This is a classic Crank Pos. Sensor problem. The CEL is not illuminated with this problem, but in all probability there is a code stored. So the first step is to hook up a scanner and see if there is a code(s) stored. Don't start replacing spark plugs to remedy this problem

Would that be the P0335 code ?

 

[Gene Horr]

Any ideas on good portable OBDII scanners?

I've got a stand-alone (Actron) and a PC-based system on order right now. If you wait a week or two I'll give a report.

 

[Gene Horr]

The units came in faster than I expected.

I've been using the Autotap PC-based system on a macbook running Parallels. I am also using the Actron CP9185.

Both system work as advertised. Both are very simple to use and have an OK interface. In both cases it only took a couple of tries to find the more obscure functions in the menu tree.

In a choice between the two it really comes down to user preference. The advantage of the PC is that you get immediate logging and can be tracking more than one function in a graph simultaneously. For me if I only had to choose one I would go for the Actron due to the simplicity. The advantages of the PC do not outweight the pain-in-the-rear factor of having to haul along a laptop and keep it charged. If I had a garage with room to leave a PC set up all of the time and was only working on my personal vehicles I would probably go for the PC. But having to check on a small fleet that are in various locations make the Actron the winner for my needs.

FWIW the auto suppliers that I checked with were all using various Actron models.

 

[FAR888]

The units came in faster than I expected.

I've been using the Autotap PC-based system on a macbook running Parallels. I am also using the Actron CP9185.

Both system work as advertised. Both are very simple to use and have an OK interface. In both cases it only took a couple of tries to find the more obscure functions in the menu tree.

In a choice between the two it really comes down to user preference. The advantage of the PC is that you get immediate logging and can be tracking more than one function in a graph simultaneously. For me if I only had to choose one I would go for the Actron due to the simplicity. The advantages of the PC do not outweight the pain-in-the-rear factor of having to haul along a laptop and keep it charged. If I had a garage with room to leave a PC set up all of the time and was only working on my personal vehicles I would probably go for the PC. But having to check on a small fleet that are in various locations make the Actron the winner for my needs.

FWIW the auto suppliers that I checked with were all using various Actron models.

Many thanks for that detailed report/perspective Gene:thumbsup:

I'll Google the Actron CP9185.

 

[pcy]

FAR, Actron code readers are good. I have CP9125. Very simple and useful device for under $50.

 

[43sqd]

Would that be the P0335 code ?

Yes that is correct. M/B's code is P2034 and the Generic scanner coverts it to P0335.

 

[FAR888]

FAR, Actron code readers are good. I have CP9125. Very simple and useful device for under $50.

Thanks pcy!

I will check it out.