2005 C200 W203 Kompressor - Engine Falters On Slow Down

[Arudge]

This is a 111 engine and the op has a 271

I've seen the locking device for the 271, a sturdy piece of kit. Probably developed to stop the idiots as per the clip i posted. I've made stuff like this for locking assemblies before, usually because somebody else has lost it.

However........

Are you telling me that the reporting on cam position for the 271 is much more comprehensive than the 111?

My 111 has a cam position sensor on the inlet only, yet it's the exhaust that skipped a tooth on mine as well as a well stretched chain, so nothing could be reported, i assume?

 

[umblecumbuz]

... the car is not registering any fault whatsoever which can be diagnosed by STAR. Also a senior Mercedes engineer has undertaken a number of test drives and has not encountered any problems.
As such do I have a right to insist upon the problem being diagnosed and fixed prior to my car being returned to me despite no fault codes being identified on STAR and the senior engineer not having experienced the issue when undertaking test drives?.

This is no longer a Mercedes specific technical question, but a consumer rights/Dealer goodwill conundrum.

Regrettably, I can see no basis on which you can insist on the correction of a problem that neither the Mercedes diagnostic equipment nor the Senior Mercedes engineer can either detect, log or replicate.

How far the Dealer will now go to satisfy your concerns will depend partly on how they view you as a customer, the collateral effects, and your determination and persuasive powers.

 

[garyreekie]

Dear Steve,

Once again many thanks for your most valued input. Before I speak with the Main Dealer's Senior Service Manager am I safe to assume that my car's intermittent engine falter on slowdown at traffic lights / cross roads could be a result of a problem when the timing chain was replaced? I do not want to come across as accusatory with the Main Dealer as they have been most supportive and empathetic to date, however, as my knowledge of the working of cars is very limited I would like to reinforce my feedback to them from experienced people on the forum that such a major repair could be the inherent cause of my intermittent problem? If yes, what would I say if the Main Dealer responded by stating that STAR has not identified any issues? Regards Gary

 

[umblecumbuz]

Hi Gary,

This is obviously a difficult one, both for you, the Dealer - and those here trying to help.

A reasonable course would be to verbally reinforce your concerns as you take back the car, then immediately put the saga in writing to the Dealer, making it clear that as the fault was not present before their work you hold them responsible, and that if the fault returns the car will also be returned.

It goes without saying that maintaining goodwill is essential for future cooperation, but so is a clear statement of your ongoing concerns.

 

[Arudge]

It goes without saying that maintaining goodwill is essential for future cooperation, but so is a clear statement of your ongoing concerns.

I think this is the most reasonable approach because this issue could , in reality, be anything.

In reality the fault needs to manifest long enough for somebody else to experience it, and therefore start to diagnose it.

These are fiendishly complex machines, it would be unfair to ask anybody to give a blind diagnosis to take to a dealer.

 

[garyreekie]

This is a 111 engine and the op has a 271.....

A 271 engine has a special tool that locks the twin camshafts in position together, when this tool is in situ, the cams cannot move. There are 2 timing marks at TDC on each cam that lines up on the cylinder head also. The bit I can't remember right now is whether the crank is at TDC or at 40' post TDC as Merc use both positions for timing on different engines, but that is irrelevant to the discussion right now.

Either way, if the cam timing is incorrect when it advances or retards the cam position must hit spec and actual value, if not the engine ECU will see it as a mis-time, it will then try and adjust the cams to suit and record its fault data. With STAR you will also be able to see this in its actual value function chain.

271's also log self adaption fault codes which is linked to timing in as much as when the cams fail to hit spec value for position and the cams advance/retard to try and correct it effects it's emissions running. In the early days this caused a bump steer for correct diagnosis as main techs went down the emissions path looking at air trim values from the MAF's and leaks from the air system (as per the guided diagnosis steps on star) and failed to find or fix the fault. No if we see no leaks on a charge air pressure test via the air box then its rocker cover off for a check of the timing.

Given that the op has had the work carried out at the main dealer I would expect them to have the special tools and use them. Like I said previously, I don't think you can successfully do the job with out them.

 

[garyreekie]

Thank you yet again for your advice and guidance. However before I speak to the Main Dealer am I right to assume that an intermittent problem such as mine could, repeat could, be the result of the replacement timing chain even though the car is not registering any fault code in STAR?

 

[Steve@Avantgarde]

I've seen the locking device for the 271, a sturdy piece of kit. Probably developed to stop the idiots as per the clip i posted. I've made stuff like this for locking assemblies before, usually because somebody else has lost it.

However........

Are you telling me that the reporting on cam position for the 271 is much more comprehensive than the 111?

My 111 has a cam position sensor on the inlet only, yet it's the exhaust that skipped a tooth on mine as well as a well stretched chain, so nothing could be reported, i assume?

The 271 is a vastly different engine. Cam adjustment only variates on one cam on the 111, on the 271 its on both. The control electronics are vastly different, the measurement of the cam positions are monitored and variated 60% more on the 271 than the 111. If you mistime a 271, it just won't run properly from the moment you turn the key.

 

[Arudge]

The 271 is a vastly different engine. Cam adjustment only variates on one cam on the 111, on the 271 its on both. The control electronics are vastly different, the measurement of the cam positions are monitored and variated 60% more on the 271 than the 111. If you mistime a 271, it just won't run properly from the moment you turn the key.

Thank you.

 

[Steve@Avantgarde]

Thank you yet again for your advice and guidance. However before I speak to the Main Dealer am I right to assume that an intermittent problem such as mine could, repeat could, be the result of the replacement timing chain even though the car is not registering any fault code in STAR?

Thank you yet again for your advice and guidance. However before I speak to the Main Dealer am I right to assume that an intermittent problem such as mine could, repeat could, be the result of the replacement timing chain even though the car is not registering any fault code in STAR?

Gary, in my professional opinion, it is unlikely that the engine timing is incorrect and it not store fault codes of any nature.

Obviously we have no specific evidence on the forum currently, its all a bit of guess because the engine has been in bits and rebuilt. But to diagnose anything you need hard evidence. STAR diagnosis is much more than a code reader, and at times you get faults which don't log fault codes, but there are usually other clues such as incorrect actual values which can point you in the right direction. How you find those is down to the capability of the individual technician.

Personally, if it was me, I would start with the fault codes, if there were none, I would charge pressure test and smoke test it just to see if it had any form of an air leak, and if that was good I would pull the rocker cover off and time up the engine.

That would be the evidence you would need to then move on to the next stage of condemning any parts that maybe faulty or even ruling out what you think might be wrong.

Like I said earlier, I have also had issues with the superchargers where the front pulley partly shearing causing unidentified loss of power issues.

 

[garyreekie]

Guys, just to let you know that yesterday I had a long discussion with the Main Dealer Service Manager and the senior engineer. Having updated them both with all your advice and guidance and the long list of faults which could be resulting in my intermittent problem the one item which they thought could be causing the issue is a sticky 'butterfly valve' caused by excessive carbonisation. I am currently awaiting an update from them in regard to whether the senior engineer has witnessed the problem during his test drives. They believe that next steps is to remove the cylinder head to ascertain whether the valve is sticking, this will take 2 hours I am told at a cost of £240 for the diagnosis. I would be grateful to learn of your thoughts as to whether the recent repairs have caused the intermittent problem as prior to the repairs I had no such engine falter / hesitation when coming to a halt.

 

[Steve@Avantgarde]

Unusual for a 271 to have valve issues on a 2005 model, they did suffer from it, but only to late 2003-early 2004 if my memory serves me correctly. Usually with this fault you got misfire readings and compression issues as well...I think. Perhaps one of the other indies could jog my cloudy memory on this subject. Its been a while since I saw one. I know at one time we were removing heads and getting valve seats replaced.

The butterfly valve they are talking about is the throttle valve actuator is it not?

 

[Arudge]

Gary.
Your dealership is clutching at straws.

Yes, the butterfly valve within the throttle body does get grubby and does cause problems, in my experience with M111 it can cause rough idle and problems moving off. Problems decelerating? I just can't see it.

You've gone to a main dealership because you thought it the best thing to do. we all understand and appreciate that, but it may not be your best option.

Your problem is this.

You need somebody highly skilled and there are very few of them around. Not just at Mercedes but in any skilled profession. I work in automotive manufacture and we are very thin on the ground, i get subcontracted out to many companies because they have nobody at that level. My local Landrover dealership has absolutely no skilled hands in it's shop either, although they would never admit it. All their diagnostic work goes to a one man band around the corner, after dark when there's nobody looking!

Mercedes relies heavily on the STAR program for it's diagnostics. STAR is a very powerful program and i'll stick my neck out here and say it would take a skilled man several years to master it, If they master it at all. The other problem is that MB's best tend to leave and start on their own as independents, which is why we rant on about indies so much.

The STAR program is typically German, not exactly intuitive and requires a very structured mind to use it. You don't usually find people with these skills working on the shop floor of a dealership. So the techs on the floor cherry pick the bits they understand and ignore the other 90%. Which doesn't help you any.

I am a manufacturer, i know how stuff is made, not necessarily how it works, especially the electronics.


Steve Avantgard has that structured mind and has the fullest understanding of STAR that i've come across to date. If i were you i'd book a days holiday and find yourself at his place.

Steve has said before, there may be no codes but there are nearly always clues in sensor values or other indicators. I don't think your people have the depth of understanding and they are clutching at straws. They'll keep changing parts until they stumble on something, run out of parts or you run out of money. This is not the way.

I apologise now if i sound like i'm preaching, but the car is cleverer than the people trying to fix it, it's no wonder people lose the faith.

This is only my opinion and it's not what you wanted to hear, but it's the way i see it. Sorry.[/QUOTE]

 

[Arudge]

I'd also like to emphasise the power of the collective, all the indies on here are worth listening too, there all here to help.

 

[garyreekie]

Once again many thanks for all your help, advice, guidance and continued support to date. In view of Steve's valued comments on next steps I think I have already mentioned that I had a vacuum problem about 2 years ago and the same Main Dealer charged me £800 to resolve the issue; I presume the pipes replaced have not become problematical in such a short time period.

I certainly agree that if I were nearer to Steve I would have no hesitation of booking my car in with him, however, Bristol is a long way from South London and at present I have no confidence in my car safely getting there with the current problem. Is there a similar well experienced independent Mercedes specialist closer to South London?

 

[LostKiwi]

Wayne Gates in Harrow, MBS Southampton?

 

[Arudge]

Sounds like there's an opportunity here for a man with a van and willing to travel.

 

[Arudge]

I think I have already mentioned that I had a vacuum problem about 2 years ago

You mentioned about having some vacuum hoses replaced, could you expand on that at all? What was the nature of the problem on the day?