SLK 55 2010, random engine stops
Discussion
595Heaven\SBK1972,
Thanks for your earlier posts\suggestions. Just an update. Looks like the key fob battery change was irrelavant sadly. A few minutes after filling up this evening, at about 30mph the engine just stopped. No warnings. Just a dead stop. Instant power steering loss. So hazards on, lights off, turn of the key and it started again.
So that's two months after the last time it happened. At a high speed I think I'd be in trouble, so needs fixing.
Days past I would have bought the kindly suggested diagnositc tool, but not being someone who wants to collect too much stuff these days I'll probably look at the MAF fix and get the spark plugs changed as well.
I don't think I've ever had a car that just stops without warning before.
Chrs.
Thanks for your earlier posts\suggestions. Just an update. Looks like the key fob battery change was irrelavant sadly. A few minutes after filling up this evening, at about 30mph the engine just stopped. No warnings. Just a dead stop. Instant power steering loss. So hazards on, lights off, turn of the key and it started again.
So that's two months after the last time it happened. At a high speed I think I'd be in trouble, so needs fixing.
Days past I would have bought the kindly suggested diagnositc tool, but not being someone who wants to collect too much stuff these days I'll probably look at the MAF fix and get the spark plugs changed as well.
I don't think I've ever had a car that just stops without warning before.
Chrs.
Edited by Mr M on Monday 7th February 21:48
It isnt going to be the spark plugs. Change them by all means but that isnt the cause.
Been a while on here so just to confirm you've changed the CPS sensor yes ? This is the sensor of choice if your truck cant start, it sits back of the engine and you get to it via passenger wheel behind the liner. It may also be the wiring which is loose or split. These trucks are at the age now where hot / cold things go brittle / loose etc.
I would change the MAF as my truck kept stalling. Reading the codes it came back with the purge valve and MAF. I replaced both however it was the MAf which was causing the stalling.
These trucks have many sensors and ECUs hence why a code reader is the way forward. These code readers can be used on most cars so buying one is a good idea and an investment going forward. I use it when buying new cars to check for codes etc. I have gone down the route your taking where I replaced sensors / ecus trying to fix problems but this gets costly so reading the codes will pin point the problem quicker and far cheaper and builds confidence in the fix.
Been a while on here so just to confirm you've changed the CPS sensor yes ? This is the sensor of choice if your truck cant start, it sits back of the engine and you get to it via passenger wheel behind the liner. It may also be the wiring which is loose or split. These trucks are at the age now where hot / cold things go brittle / loose etc.
I would change the MAF as my truck kept stalling. Reading the codes it came back with the purge valve and MAF. I replaced both however it was the MAf which was causing the stalling.
These trucks have many sensors and ECUs hence why a code reader is the way forward. These code readers can be used on most cars so buying one is a good idea and an investment going forward. I use it when buying new cars to check for codes etc. I have gone down the route your taking where I replaced sensors / ecus trying to fix problems but this gets costly so reading the codes will pin point the problem quicker and far cheaper and builds confidence in the fix.
I'm curious to know how this goes. Read on for my potential solution...
If I've not read everything forgive me, but was this a problem prior to CPS being replaced by Indy garage?
I'm no mechanic, but have tackled a few things successfully over the years, and I'd start by a process of elimination and not discounting things that I think are fine...
So, first question is above.
Next would then be was the correct part actually fitted? Even it if was, do you know 100% it isn't faulty (for whatever reason and not unheard of). Maybe garage fitted wrong part, might be wrong part in the 'right' box...what appears on your invoice may not be what is actually physically fitted to your car...not attempting to doubt your Indy, but these things can happen.
However...I too have an r171 55 and when I bought it it (on the long journey home actually) it gradually 'lost' throttle response, so full power unavailable and a 3 second delay when pressing throttle at any throttle opening...not much fun at city roundabouts plus thinking I'd bought a car with 'problems' before I'd even got home...
It was fine on test drive(s) prior to purchase, including the day I picked it up.
Restarting car would cure it. Over time it grew worse, and any full throttle application would trigger it going into this kind of delayed action/limp mode. Pull over, turn it off, on again and ok until full throttle applied. It would also disable ESP etc.
This problem and solution I established via internet was the throttle pedal, circa £30 from a dismantler, over £300 from MB. I tried the £30 option and it cured the problem.
If you can physically check the TPC yourself then great, but as it is intermittent it is (I guess) electronic and not mechanical. The throttle pedal has a load of electronics in it which can become corrupted.
I'd be tempted to look at throttle pedal myself. Try the factory reset via ignition (found on google and forums) for a start but I don't think that will change anything. The throttle pedal is easy to change, one screw and a electronic connection, even I could do that!
The pedal was generic to most r171 models, not exclusive to the 55.
Keep us posted!
If I've not read everything forgive me, but was this a problem prior to CPS being replaced by Indy garage?
I'm no mechanic, but have tackled a few things successfully over the years, and I'd start by a process of elimination and not discounting things that I think are fine...
So, first question is above.
Next would then be was the correct part actually fitted? Even it if was, do you know 100% it isn't faulty (for whatever reason and not unheard of). Maybe garage fitted wrong part, might be wrong part in the 'right' box...what appears on your invoice may not be what is actually physically fitted to your car...not attempting to doubt your Indy, but these things can happen.
However...I too have an r171 55 and when I bought it it (on the long journey home actually) it gradually 'lost' throttle response, so full power unavailable and a 3 second delay when pressing throttle at any throttle opening...not much fun at city roundabouts plus thinking I'd bought a car with 'problems' before I'd even got home...
It was fine on test drive(s) prior to purchase, including the day I picked it up.
Restarting car would cure it. Over time it grew worse, and any full throttle application would trigger it going into this kind of delayed action/limp mode. Pull over, turn it off, on again and ok until full throttle applied. It would also disable ESP etc.
This problem and solution I established via internet was the throttle pedal, circa £30 from a dismantler, over £300 from MB. I tried the £30 option and it cured the problem.
If you can physically check the TPC yourself then great, but as it is intermittent it is (I guess) electronic and not mechanical. The throttle pedal has a load of electronics in it which can become corrupted.
I'd be tempted to look at throttle pedal myself. Try the factory reset via ignition (found on google and forums) for a start but I don't think that will change anything. The throttle pedal is easy to change, one screw and a electronic connection, even I could do that!
The pedal was generic to most r171 models, not exclusive to the 55.
Keep us posted!
Edited by BlimeyCharlie on Wednesday 9th February 11:48
The reason I took it in to have the CPS replaced was due to the engine cutting out randomly as my previous 55 did a complete stop on me down the A1 but that had warm start problems as well before that happened. My current car doesn't have any starting issues which I believe are symptoms of a worn out CPS.
Anway, post CPS replacement it's still an issue although it doesn't happen regularly . Two months between the last occurance and the previous one. The only two similar circumstances were just after I'd filled up with fuel but that may be just coincidence. As a previous poster suggested, a fault meter would be useful but I'll see how it goes. Long journey shortly as well :-( as it's my only vehicle at the moment. I'm starting to feel a car just needs to be two things. Reliable, and practical. Getting old.
PS. My issue is the engine just stops dead. I don't have the luxury of a warning :-\
Anway, post CPS replacement it's still an issue although it doesn't happen regularly . Two months between the last occurance and the previous one. The only two similar circumstances were just after I'd filled up with fuel but that may be just coincidence. As a previous poster suggested, a fault meter would be useful but I'll see how it goes. Long journey shortly as well :-( as it's my only vehicle at the moment. I'm starting to feel a car just needs to be two things. Reliable, and practical. Getting old.
PS. My issue is the engine just stops dead. I don't have the luxury of a warning :-\
Edited by Mr M on Wednesday 9th February 20:25
Thanks for replying.
I agree about a car being reliable, practical is subjective! It is nice to have a change I think, I've had 2 SLK's, a 350 and a 55, great cars.
My point about the throttle is yours may totally corrupt itself to the point where it cuts out? It is that, or CPS (again/still) or ignition related, but it is going to be something simple if it runs well the rest of the time. Read on...
When I had the throttle problem it would sometimes cause the EML light to come on, sometimes not. Car would run fine though.
Have you checked all battery connections are tight? Wiring not damaged in that area?
Please don't think I'm suggesting anyone has done anything daft, but...I took my M3 to the 'best' bodyshop locally for repairs about 10 years ago and (unknown to me) they drained the battery, causing faults with the wing mirrors operation, and frankly didn't have a clue how to sort it out.
It was sent to BMW to diagnose...at bodyshop's own cost....BMW diagnosed x2 new wing mirrors were required, plus painting in Carbon Black, plus fitting, plus programming, plus VAT...all because they flattened the battery in the bodyshop. I worked out what they'd done, asked if they'd flattened the battery, they had, then it all made sense and cost nothing to to get the mirrors working as they did before...
That was one problem, the battery compartment being full of water was another problem, as they'd forgotten to put some trim back. I found this out about 2 weeks after I'd had the car back.
I'd start with the basics, check battery connections, then go from there. Is fuel cap ok too? It will be something simple!
I agree about a car being reliable, practical is subjective! It is nice to have a change I think, I've had 2 SLK's, a 350 and a 55, great cars.
My point about the throttle is yours may totally corrupt itself to the point where it cuts out? It is that, or CPS (again/still) or ignition related, but it is going to be something simple if it runs well the rest of the time. Read on...
When I had the throttle problem it would sometimes cause the EML light to come on, sometimes not. Car would run fine though.
Have you checked all battery connections are tight? Wiring not damaged in that area?
Please don't think I'm suggesting anyone has done anything daft, but...I took my M3 to the 'best' bodyshop locally for repairs about 10 years ago and (unknown to me) they drained the battery, causing faults with the wing mirrors operation, and frankly didn't have a clue how to sort it out.
It was sent to BMW to diagnose...at bodyshop's own cost....BMW diagnosed x2 new wing mirrors were required, plus painting in Carbon Black, plus fitting, plus programming, plus VAT...all because they flattened the battery in the bodyshop. I worked out what they'd done, asked if they'd flattened the battery, they had, then it all made sense and cost nothing to to get the mirrors working as they did before...
That was one problem, the battery compartment being full of water was another problem, as they'd forgotten to put some trim back. I found this out about 2 weeks after I'd had the car back.
I'd start with the basics, check battery connections, then go from there. Is fuel cap ok too? It will be something simple!
Well, yes in a way. Down a long Dorset road on the 12th of Feb I was doing about 50mph. The engine cut, so I instinctively planted my foot on the accelerator and like the last time it happened at that speed (strangely, also in Dorset at the start of December), the engine picked up again straight away. So maybe it is accelerator related. But, it hasn't done it since. Having said that the car is normally only used about once a week for about 40 miles at the moment.
Since the car has been back in a dry garage, I've had no on the road cut outs but very occasionally the car will cut out very soon just after I've started it up ie when I've just filled up with fuel, and move off. I believe the connection with the key to the ignition system is sometimes a bit hit and miss also. You'll plug the key in, turn it to position one and nothing happens. Take it out, and have another go and it's ok second time. So maybe a key\ignition communication issue. The chap that services the car did notice this the service before last and said to keep an eye on it. He always changes the key fob battery as well so it's not that.
Edited by Mr M on Wednesday 8th May 21:51
Mr M said:
Since the car has been back in a dry garage, I've had no on the road cut outs but very occasionally the car will cut out very soon just after I've started it up ie when I've just filled up with fuel, and move off. I believe the connection with the key to the ignition system is sometimes a bit hit and miss also. You'll plug the key in, turn it to position one and nothing happens. Take it out, and have another go and it's ok second time. So maybe a key\ignition communication issue. The chap that services the car did notice this the service before last and said to keep an eye on it. He always changes the key fob battery as well so it's not that.
Thank you! Again, this is the exact same symptoms as mine! And the key symptoms when warm as well, what I find helps greatly is being very slow with the key, if I wait a few seconds before turning to each position it is generally fine.Edited by Mr M on Wednesday 8th May 21:51
I recently watched these two videos of Youtube, and I'm pretty sure it will be one of these issues:
https://www.youtube.com/watch?v=K_-TLfRkP6Y&t=...
https://www.youtube.com/watch?v=vl9U_pQzKfo&t=...
1. Ignition barrel as you mentioned (I have a locksmith changing this next week)
2. Faulty Engine ECU (Motor Electronics Unit - Likely heat damage)
Mercedes in their infinite wisdom decided to mount the engine computer directly onto the hot engine! There was a service bulletin in 2009 where these were being changed due to faults related to the heat cycles breaking the ECU. Whenever the ECU gets hot from the engine it starts to lose communication and blanks out
I do have STAR/ DAS. But unfortunately no codes are logged. This does makes sense as the ignition barrel simply thinks you have removed the key, and the Engine ECU will only report if it receives, or interprets a message of something not being quite right, yet won't be aware if it, itself blanks out temporarily.
The ignition option is only £220 fitted (used - new not available) so worth trying, and it means I will have my old spare to refurbish myself from watching the Youtube video to make better than new if the replacement fails.
The Engine ECU is around 400 - 600 for a used one, and the cloning of the unit already in the car.
Both these issues make logical sense from the cut outs we have both experienced from a petrol station etc as well, for the ignition barrel, if the contacts are going to fail on that occasion, it is likely just after they have been operated and something not catching correctly..
For the ECU, these are the worst conditions for it being hot. The engine is already warm, yet there is no airflow from moving keeping the ECU cooler - Thankfully all my cut outs have been when slow / not moving so does make sense.
I'd rather not play parts darts! but as there are no fault codes, and the issues are so intermittent, no garage has been able to find or replicate an issue. Frustrating, as apart from this the car is perfect and a joy to drive, worrying it could cut out at any moment is quite scary though!
Edited by gregpot2000 on Thursday 9th May 12:23
Good research I'll have a look at those videos and make note of your findings. As you say, a total engine stop at high speeds could be quite disasterous.
PS I also do as you do if the first ignition is not successful. Take the key out, place it firmly back in and slowly turn to position one and this usually works second time.
PS I also do as you do if the first ignition is not successful. Take the key out, place it firmly back in and slowly turn to position one and this usually works second time.
Edited by Mr M on Saturday 11th May 14:07
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