S320 CDi (W221) intermittent acceleration and kickdown

[PaulMason]

Does the car do a kangoroo when you press the accelarator fully to the floor? If so most likely, as mentioned here the turbo actuator needs to be looked at. Had a similiar isue on a older OM642 and there were no codes on STAR

Hi Phobos, have driven about 199 miles today and all fine initially and then accelerating moderately up a hill there was a slight kangaroo/surge/judder as the power seemed to come an go in a quick pulse and then it went into limp. Would that be the kangarooing you described?

 

[phobos]

@PaulMason, that does sound like kangorooing to me. If there are no codes in STAR, it will most likely be the turbo actuator. If you are handy with spanners you might be able to take it out and open it ( carefully) Some of contacts wire might be broken. Turbo actuators can be refurbished by companies such as TurboVanes ( used them in the past myself)

 

[PaulMason]

@PaulMason, that does sound like kangorooing to me. If there are no codes in STAR, it will most likely be the turbo actuator. If you are handy with spanners you might be able to take it out and open it ( carefully) Some of contacts wire might be broken. Turbo actuators can be refurbished by companies such as TurboVanes ( used them in the past myself)

Thanks, I may give that a go. There is a perculiar noise occasionally, a sound as if something is graunching a little and I wonder if the actuator or the egr are sticking a little. On the basis I haven't yet worked out where the EGR is located, I may start by taking the actuator off, opening it, checking for loose or broken wiring and cleaning and alike. Doesn't look massively complex, but will wait and order a air filters, breather and turbo seal as whilst the inlet is off, seems daft not to

 

[phobos]

sound like a good next steps me! a check / clean of EGR is also a good idea

 

[PaulMason]

Quick update. A few days of driving and no issues, then a third day and it did the limp thing once and then had another EGR fault showing. I decided to remove and clean (found a handy YouTube video tutorial) as only 2 bolts and a little bit of cleaning. Not terrible, but very sooty. Reinstated and have done 50 varied miles since and so far so good. In truth, given the occasional kangaroo/judder on acceleration, I suspect it is the turbo actuator or sticky vanes, but for now I did the EGR and see how I go. I've done circa 1500 miles in it since oil and filter done and not a drop of oil used this far so I'm pretty pleased with that for a leggy car

 

[phobos]

great to hear that the EGR clean has helped but it does sound like your actuator is going. keep us posted

 

[W1ghty]

Quick update. A few days of driving and no issues, then a third day and it did the limp thing once and then had another EGR fault showing. I decided to remove and clean (found a handy YouTube video tutorial) as only 2 bolts and a little bit of cleaning. Not terrible, but very sooty. Reinstated and have done 50 varied miles since and so far so good. In truth, given the occasional kangaroo/judder on acceleration, I suspect it is the turbo actuator or sticky vanes, but for now I did the EGR and see how I go. I've done circa 1500 miles in it since oil and filter done and not a drop of oil used this far so I'm pretty pleased with that for a leggy car

Give the inside small hole on the exhaust back pressure sensor a spray clean as well , it fills with black soot . Quick easy job

 

[W1ghty]

Quick update. A few days of driving and no issues, then a third day and it did the limp thing once and then had another EGR fault showing. I decided to remove and clean (found a handy YouTube video tutorial) as only 2 bolts and a little bit of cleaning. Not terrible, but very sooty. Reinstated and have done 50 varied miles since and so far so good. In truth, given the occasional kangaroo/judder on acceleration, I suspect it is the turbo actuator or sticky vanes, but for now I did the EGR and see how I go. I've done circa 1500 miles in it since oil and filter done and not a drop of oil used this far so I'm pretty pleased with that for a leggy car

This was my actuator clean out

OM642 Actuator clean out and refit .

Due to the sunshine , I had done this job 3-4 years ago so I thought I would remove the actuator again and clean it out . Turbo shield removed , 3 bolts . Then the split ring on the actuator arm popped off very carefully you could tie some cotton on it , but I only did this when I refitted it ...

forums.mercedesclub.org.uk

 

[PaulMason]

Give the inside small hole on the exhaust back pressure sensor a spray clean as well , it fills with black soot . Quick easy job

Thanks W1ghty, is that in the same general area? Is it the sensor that sits between the turbo and EGR by any chance

 

[W1ghty]

Thanks W1ghty, is that in the same general area? Is it the sensor that sits between the turbo and EGR by any chance

That’s the one , 24mm deep socket , watch you don’t drop the chrome coloured o ring that’s below it .

 

[PaulMason]

That’s the one , 24mm deep socket , watch you don’t drop the chrome coloured o ring that’s below it .

Brilliant, thanks again for the guidance. I've also bought (not to fix this problem persay, but just for good maintenance really) a pair of air filters and the turbo and breather seals, so I'll do the back pressure sensor when I do them.

I'll do the actuator too, great guidance on that thread thanks, and I'm definitely using a piece of cotton or alike as had visions of that clip disappearing as I tried to remove it!

 

[Larkone]

Brilliant, thanks again for the guidance. I've also bought (not to fix this problem persay, but just for good maintenance really) a pair of air filters and the turbo and breather seals, so I'll do the back pressure sensor when I do them.

I'll do the actuator too, great guidance on that thread thanks, and I'm definitely using a piece of cotton or alike as had visions of that clip disappearing as I tried to remove it!

While you are in that area it might be worth a new PCV valve (has fitted orange seal that does not get sucked into turbo) as the rubber diaphragm degrades and splits - easy job and reduces the amount of oil blown into the turbo. Mine ran better afterwards

 

[PaulMason]

UPDATE: I actually never got around to sorting this fully and it continued to be a little surgy/hesitant and went into limp from time to time (engine off and on always reset) so I just got used to "driving around" the problem. In December, I started to get a tick tick tick on idle and based on the noise thought it was a injector seal. I was also getting quite a lot of black smoke out of it under hard acceleration. Whilst a cheap part, I didn't fancy the rigmarole of trying to getting the gunky injector out so priced it with a few places. The local main dealer was cheapest at £110 all in (they actually ended up doing the 3 on the driver side bank for £148 which I thought was a bit of a bargain as I know they can be tricky to get out).

Since then, (even though it was not intended to fix this particular issue) the car has been way better, it still (though a lot less frequently) has its hesitation (always on a super light throttle now) but has only gone into its pseudo limp twice in about 1000 miles so way way better (though not perfect). Occasionally upon a heavy burst of throttle, there is some black smoke, but it generally does it once and then is fine upon subsequent heavy throttle applications on the same journey.

I am considering next steps and thinking the turbo vanes actuator replacement, but given the symptoms massively improved (I would say by about 80% as a gut feel) by the 3 injector seals, could the others be on their way and causing the left over issue? At c. £140, its about the same as the actuator? Thoughts welcome as sadly can't do both now (I like headaches so bought a "cheap" ML 320 for the good lady, so need to divide spend a couple of ways now and its getting some bits and bobs sorted in a couple of weeks)?

My one slight confusion is the smoke at times - I would have thought the DPF would have trapped any unburnt diesel (which I a guessing the smoke is) upon a hard throttle when its been a little hesitant? The DPF and EGR seem to be working (have regened the DPF on the iCarsoft a couple of times and done a EGR activation test and the numbers moved)? I also did a turbo actuation test and again the numbers move on this from something like 1100mbars to 900mbars so that's my other thought on the actuator vs. injector seals (though it moving in the test and moving quickly enough in the real world of driving may well be a different matter)

Sorry, now reading that, its a bit of an essay - to simplify - I did injector seals and things got way better - do I invest in more as the remaining symptoms are similar to the symptoms improved upon by the first 3 seals or am I being too simplistic?