W208 3.2 - Engine cutting out when warm

[mtayre]

Hello all,

I'm back again with yet another issue with my car, they seem to be endless at the moment. Basically the car is cutting out when warm and won't start up again for a few minutes, it then continues to do this making it impossible to go anywhere. Must apologise for the essay but just wanted to be detailed with what has happened.

The problem first showed on Saturday, had a couple of mile run and switched off for five minutes whilst in a shop, came back out to start the car and it failed to start properly first time, fired and seemed to be starting but as if it was only working on one cylinder and eventually cut after about 3 seconds. Turned the key again and started no problem but the engine management light was on. Car drove fine, no problems at all.

Later in the day started the car up, no engine management light and the car was working fine. I went out of town, about 20 miles away no problems at all. Parked up for an hour came back started up and everything was fine. Drove no more than a mile and then the engine cut out completely, all lights came on the dash, but no malfunction warnings in computer. Tried to restart and nothing, did not even attempt to turn over, no starter motor click nothing as if the immobiliser had kicked in. After about five minutes, started up again without any warnings at all. Drove another 500 yards and then ABS/ESP/BAS failure messages all popped up. Managed to limp the car back home with all these on and other than the obvious things that wouldn't work it was fine.

Started it up on Sunday to see if the faults were still there and all was fine again. Went for a small run to get it up to temperature to see if I could reproduce the fault and sure enough, as soon as it hit normal running temperature it cut out again. On attempt to restart nothing at all, no starter motor click or turn over.

So far I’ve had the battery tested, no faults and checked the Crank Position Sensor no faults. I can’t get into the garage until tomorrow, to see if there’s any errors stored so does anyone have any other things that I should look out for? I'm really stuck this week without the car.

Cheers

Michael

 

[carat 3.6]

Did you check the crank sensor when it was hot? They tend to work ok when cold.

 

[mtayre]

The crank position sensor has been replaced, the old one tested ok still after been heated up.

 

[BlackC55]

I've had a few cam sensors fault recently. They bring up a fault code when faulty. Also when the car cuts out it maybe worth checking the fuel pressure. You will need a gauge to check it. If you have no pressure look at the fuel pump and relay.

 

[mtayre]

Update, the car has been to a garage since Wednesday, they stated that the fault was wire from the CPS to the ECU losing signal. Took them two days to guess at this. They told me that the problem had been fixed, road tested the car and everything was fine.
I took the car back and went to work which was less than a mile away. After 4 hours went back to the car, started it up again and went to put petrol in, after about 500 yards it was back to cutting out, exactly the same as before.

Since I go the car home, I've checked the relay and everything seems to be fine, no damaged solder on any of the joints.

I'm quiet angry as it cut out on me in the middle of the busiest junction in the town at rush hour, nearly got took out by a lorry. I feel that they have given me a car back in a dangerous condition with the assurance that it had been fixed. Can anyone please advise on what I should say to them in the morning. They open at 9 and I really want to be prepared to let them know my thoughts in a nice polite way.

 

[BlackC55]

Intermittent faults can be very difficult to fix if they can't be replicated. They may have had some fault codes to go on so followed them.

Just be polite and say that the car still had the fault. Can they look at it again. If they are any good they will. Do they know mb's ?

 

[mtayre]

They took the car back in on Christmas eve but were only open for a few hours, so didn't have much of a chance to take a look. They did say that there was a slight misfire; I'm expecting an update from them today as they are back in.

I've not used this garage before but they do specialise in German cars and have said they have experience of Mercedes. I’m going to give them a couple of more days looking at it and if there’s no progress going to take it through to my usual garage.

 

[grober]

What you describe are classic CPS symptoms. Its possible the new ?? CPS is faulty /wrongly installed---- it does happen. Other possibility might be a faulty/corroded engine earth strap. They did renew the CPS sensor and not just the lead didn't they?

 

[mtayre]

Yes the CPS has been replaced along with lead, but if it was the CPS the car would still turn over after it cut out I think? At the moment once it cuts out it does not turn back over until 3-4 minutes later.

The earth has been checked and all seems fine. It never has issues starting other than after it's cut out.

 

[grober]

If the car won't turn over but all the dash lights are on begins to sound like an intermittent immobiliser problem. [ assuming the immobiliser prevents the starter turning over among its other functions??]

 

[mtayre]

Just had a call from the garage, it's not doing it anymore. They've had it out on several runs and its running faultless now. There's no stored error codes and it's not flagging any new ones. They are going to keep it this afternoon and keep running it to see if it does happen again.

Cheers for the help everyone

Michael

 

[mtayre]

After 105 test miles where it ran faultless i finally got the car back. Popped out got back in to restart it and bang, same issue again. I did notice an error flash up stating defective display. Same problem with the car not turning over but all iginition lights on and the engine fan running at full tilt. The garage came out to take a look and it was still doing the same thing. They are going to take it back in tomorrow morning.

 

[mtayre]

Yet another update on this issue. They have had the car since last Friday now and have managed to reproduce the fault but not got ay error codes off it up until today when then received a C1022 ESP Can Communication with Engine fault. N47-5.

Any ideas on this one, they are starting to talk silly money now for a car that's only worth around £3k.

 

[jaymanek]

It does indeed sound like a communication issue.... If the car isnt turning over that rules out the crank sensor...
I would be looking more along the lines of key, ignition, Engine ECU or ESP control unit.

N47-5 is your ESP control module, could well be this.

 

[mtayre]

They have suggested that I try the car again for a few days with the ESP control until disconnected. They say that it is ok to run the car like this to check to see if it is this. They have explained that I’ll be left without ESP, BAS, ABS which I expected anyway with it being disconnected.

Any ideas on the part number and price, I'm been quoted £1500 to buy and for fitting.

 

[Alex Crow]

Firstly, you will probably find a second hand ESP module for £200 or less - you have a second hand car after all, and they almost never fail.

Moving on though, it is hard to imagine how the ESP module could cut the engine, or stop the starter turning. It does have the facility to control engine output as part of the ESP operation, but not to actually cut the engine.

Really helpful would be a list of all stored and current faults in all modules, I suspect several other CAN faults being reported with the engine ECU.

EDIT: A quick look on ebay shows plenty for sale in the USA at around the £100 mark.
I would expect Dronsfields to have one available.
Always match the exact part number.

 

[mtayre]

I've got my car back and took it through to MercSpec in Middlesbrough who I usually use. I'm going to leave it with them until they can get the bottom of whats going on. I'll update with what the final fix is.

Cheers for everyones advice on here.

 

[mtayre]

Update as promised.

Mercspec have taken a look and seem to have traced the problem back to the K40 relay module. Whilst tracing the wiring loom they have also found oil leaking into it. They are going to replace the module and clean up the wiring loom and put in a repair to prevent it the oil leaking back there.

Should get the car back early next week. Again thanks everyone for the informative and helpful advice.

 

[mtayre]

I got the car back yesterday lunch time and all seemed fine. Finsished work, went home started fine. A couple of hours later went shopping and as I went to start it when I finished shopping, the same thing as before, all ignition lights on and the car won't crank at all. Engine fan running at full speed whilst the ignition lights are on.

The car is going back in to the garage today, I managed to phone them lastnight. They did mention that the car was showing some low voltage error codes, I'll see if I can get the full list off them when I take it through today.

I'm really starting to lose faith in the car now.

 

[mtayre]

Another update from the garage, and everything is pointing towards the Engine ECU being at fault. They've checked all the wiring, no breaks can be found. The car is still getting intermitant voltage issues.

Is this something that I can buy second hand and if so what kind of other work will be needed, ie programming, etc? At the moment a repair is looking at around the £500 mark if it can be done through them.