W205 2015 Om626 1.6 Diesel Shaking / Exhaust/ Injector issue 100k miles

[Mark1974]

Hi All

Apologies for long winded chronological list below.....Effectively car shaking when idle, especially at cold, awful clatter accelerating between 1500-2000 rpm in any gear ...

Details of all work I've done so far .. rang a Mercedes Independent specialist today May 4th 2023 Hopefully they can help but thought I'd checked here. Based in South East Ireland.

Time Period:

To Day 1: EML : Checked Code : BackPressue Sensor Fault...Cleared ...fine

To Day 2: Car 'Pulls Back' as if something choking engine, then surges forward ...all ok

To Day 3: Start Car Cold > Engine Shaking; Car Shaking but Rev Counter OK, Smell of Fuel / Exhaust , Rev Engine All OK, Drive ...Serious Injector Clatter or Pinging From Engine. No EML , Hand Held Scanner,
nor XENTRY Clone Software Codes.

BUT Software showing AT IDLE:

Injectors >9 mg/stroke and as high as 13 mg/stroke at idle, improves when driving ; Correction Values Cyl 1,3,4 ALL MINUS - adding to Cylinder 2 at +5.00 mm^3 ;
Low Pressure EGR at 40%, Air Mass at idle 20-22 kg/hr. No EML , Hand Held Scanner, nor XENTRY Clone Software Codes.


To Day 7: Check BackPressue Sensor, Damaged and Thin Pipe Blocked. Remove and Clear Thin Pipe and New Sensor

NO CHANGE: Car still shakes, Rev counter static, Injectors >9 mg/stroke and as high as 13 mg/stroke at idle, improves when driving ; ; Correction Values Cyl 1,3,4 ALL MINUS - adding to Cylinder 2 at +5.00 mm^3;
Low Pressure EGR at 40%, Air Mass at idle 20-22 kg/hr. No EML , Hand Held Scanner, nor XENTRY Clone Software Codes.


To Day 12: Plug out MAF : All Values come close to within range with minimal Injector Clatter or Pinging from Engine. Day 8>12 : Receive 'Used' MAF from Mercedes Benz Germany

NO CHANGE: Car still shakes, Rev counter static, Injectors >9 mg/stroke and as high as 13 mg/stroke at idle, improves when driving ; ; Correction Values Cyl 1,3,4 ALL MINUS - adding to Cylinder 2 +5.00 mm^3;
Low Pressure EGR at 40%, Air Mass at idle 20-22 kg/hr. No EML , Hand Held Scanner, nor XENTRY Clone Software Codes.

To Day 20: (Was awaiting Injectors) : Remove Injectors.Injectors from Car were badly 'burnt' and 'puddle' of diesel on top of engine. 1 Injector slightly oily. Fit 4 New Bosch Injectors (1 was a Test Injector: Codes still readable on nozzle).Use Clone Zentry to code.

SLIGHT CHANGE: Car still shakes, Rev counter static, down to 7 mg/stroke and as high as 10 mg/stroke at idle, improves when driving ; Correction Values STAY THE SAME = Cyl 1,3,4 ALL MINUS - adding to Cylinder 2 +5.00 mm^3;
Low Pressure EGR at 40%, All Values out of range. Injector Clatter and / or Pinging Remains but not as harsh.
Smell of Exhaust and Fuel near gone. HOWEVER Air Mass at idle 20-22 kg/hr. No EML , Hand Held Scanner, nor XENTRY Clone Software Codes.

To Day 23: Strip down various items and try remove the High Pressure (Uncleaned Exhaust Flow) EGR...Cant get it out of Intake

To Day 26: Strip down various items and try remove the Low Pressure (cleaned Exhaust Flow) EGR...Manage to Remove, slightly carboned ,
gauze into cooler heavier carboned, clean both and reinstall.

A FURTHER SLIGHT CHANGE: Car still shakes, Rev counter static, Injectors >6 mg/stroke and as high as 8 mg/stroke at idle, improves when driving ; BUT This Time .. Correction Values are Intermittent ...
Initially they start at the usual = Cyl 1,3,4 ALL MINUS - adding to Cylinder 2 at +5.00 mm^3
however .... with EGR Actuation & EGR Temperature Actuation ...Values correct to= Cyl 1,3,4 ALL MINUS (some as near as 0.04 mm^3) - adding up to Cylinder 2 at +.86 mm^3 to +1 mm^3 and Air Mass at idle 25+ kg/hr.
BUT ALL RESETS post switching engine off and correction values back to Cyl 1,3,4 ALL MINUS - adding to Cylinder 2 at +5.00 mm^3

Low Pressure EGR at 0%, Injector Clatter and / or Pinging Remains same as last time but not as bad as initially.
Smell of Exhaust and Fuel near gone. HOWEVER Air Mass back at idle 20-22 kg/hr. No EML , Hand Held Scanner, nor XENTRY Clone Software Codes.

To Day 28: Try to extract LOW Pressure EGR Temperature Sensor to see if Carboned up (although range appears ok). This was done after
one particular test drive where excessive white vapour from exhaust was noted while driving. NO Loss of any Coolant. White vapour episode has not occured again.

However Cannot extract Sensor. May also have damaged 'bolt'. Extract Throttle Body and Clean. Extract MAP and IAT Sensor (ver badly coated in Oil).
Also noted Oil in Turbo Outlut pipe to Intercooler. Intercooler after 8 Years must be quite Messy.

To Day 31: Further Xentry Monitoring:

(A) Found Author Data : IMA section which states the 1st Injector Code is FALSE , if I switch Codes , Its always the 1st Code,
even if I put in Old Codes. HOwever ALL Codes received a correct tick mark when transferred to ECU.

(B) In the same Author Data Section: Switching ON the Exhaust Flap Sensor immediately 'raises' the Air Mass at idle to 30+ kg/hr and all shaking stops.
All Injector Quantities and Correction Values go to near perfect. This then stops post 30-45s or when Test completes.

Day 31+ : Plugged out MAF. Driving Car, no shaking, very very slight Injector Clatter / Pinging but obviously EML and no power.

Overall: No EML , Hand Held Scanner, nor XENTRY Clone Software Codes.
BUT

(A) Injector Coding possibly not Correct
(B) Air Mass Sensor (Replacement and Original) or ECU and Air Mass out of sync
(C) High Pressure EGR Stuck at 0% (it does actuate) ... but cant get it out of Intake
(D) Temp Sensor in Low Pressure EGR : Carboned Over ? Not requesting opening of Valve and/or not in Tandem with Exhaust Flap?
(E) Exhaust Flap : Stuck partially Open?

(F) The Engine is F**^%%$$

Any views? Thanks

 

[bembo449]

sounds like a blockage , poss DPF or EGR issue

 

[Mark1974]

sounds like a blockage , poss DPF or EGR issue

Yep I'm thinking it's that high pressure EGR where the 'uncleaned' exhaust air goes thru is either stuck open or closed I'm thinking closed. I just cannot get it out of intake. ..dpf apparently has low level of soot but the software is a cheap copy so not sure. ...the low pressure (while awkward) was not hard to dismantle although it's not direct attached into engine.

 

[Mark1974]

sounds like a blockage , poss DPF or EGR issue

I should have left it into mechanic but hey ... It passes the time... hopefully mechanic can now get EGR out and hopefully there will be no damage and my changing of injectors won't be in vain

 

[dvarley]

Shaking at idle normally is down to hydraulic engine mountings failure. Clattering noise can be bad injectors. Needs a Star diagnostic. That will tell you if injectors are out.

 

[mersum1es]

Xentry Compresion test? All pressure sensors read ATM pressure when ignition on but engine not started? Back pressure readings when shaking / not shaking?? IMA coding... what if you swap injectors and codings? Have you done injector leak test? How about fuel quantity valve test?

 

[Mark1974]

Xentry Compresion test? All pressure sensors read ATM pressure when ignition on but engine not started? Back pressure readings when shaking / not shaking?? IMA coding... what if you swap injectors and codings? Have you done injector leak test? How about fuel quantity valve test?

Thanks for revert and person previous to you.

Over the weekend I pulled the High Pressure EGR out (eventually got it out)...badly carboned up as was 'port' in intake it connects into, cleaned everything I could as best I could, tested egr ...open and closing easy...put back in the next day .

Unfortunately still shaking at start up, still injector clatter at 1500-2000 rpm under load..still the dreaded MAF under 25 kg/hr at idle.

The copy of xentry doesn't seem to allow Compression test.

Regarding Back Pressure, no issues with readings and it was the first thing / sensor I changed but more importantly the thin metal tube was blocked and I unblocked same (2 nights soaking). No grey sludge on oil cap since this was done ...which is good.

I didn't do a leak of test as I changed the injectors ...they're all new...My xentry states or seems to accept codes using adaption section but under ima in Author Tests ..states the 1st cylinder code is false ...if I change around codes it states whatever I put in cylinder 1 is false. I'm going to leave it into independent to start with coding of injectors

Quantity Valve actuates.

Ive probably put 20-30 hrs in work in so far, everything has definitely benefited the car( more power, quieter (save accelerating), cruises at 75+ mph...) And once more Not A Single Code anywhere!

Waiting for Mercedes Indo Mechanic to revert to me at this stage.

 

[Uncle Benz]

It sounds like you’ve been through the fuel system quite thoroughly. Have you considered checking for a stretched timing chain?

 

[Mark1974]

It sounds like you’ve been through the fuel system quite thoroughly. Have you considered checking for a stretched timing chain?

It crossed my mind tonight for the first time... No rattle when when revving however ( had en E46 and a w203 in the past had rattling chains) ... Im hoping the independent specialist can have a look this week

 

[Mark1974]

Someone called Henri left a message i just saw it 9 months apologies so for you Henri....Car stuttered on till Nov When turbo went, got it replaced, Although it sat in mechanics for 3 mths after the turbo where they intermittently tried diff tests apparently...and they could not get any codes .....got it back March this yr. Immediately then I replace low pressure Egr as it threw a code multiple times for first time ever...new 02 sensor etc, still slight shake at start up , no real smoke, the slightest injector clatter which you'd have to look out for TBF. Good thing is while it was in garage ...I bought a 24yr old W210 E200 Elegance... Nothing complicated drives great, I've done engine work and the aforementioned garage are now putting in front and rear suspension save only the springs and brakes plus discs allway round

 

[Mark1974]

Looking forward to getting w210 back and I'll probably use it and sell the w205. The diesel Renault engine is not great unfortunately...moreso the whole DPF,air intake, turbo set up ...the car is beautiful and comfortable but engine ...nope

 

[HumzaAhmed155]

Looking forward to getting w210 back and I'll probably use it and sell the w205. The diesel Renault engine is not great unfortunately...moreso the whole DPF,air intake, turbo set up ...the car is beautiful and comfortable but engine ...nope

So the issue in the end was the turbo?! I have literally the exact same issue but at 60k miles lol

 

[Mark1974]

So the issue in the end was the turbo?! I have literally the exact same issue but at 60k miles lol

Turbo improved it, put back in old injectors, improved it further, have one refurbished injector in it, going to swap out for used one, as I think these refurbed ones are not coded properly after they are rebuilt..I replaced the low pressure Egr and mesh wire gasket, as car was showing low pressure gas flow p0401 ...it now still shows same ...looks like blocked Egr cooler or crack in honeycomb in pdf ...have to have same looked at. But overall couldn't tell you what the exact issue is ..have offers on the car as it is(still smoking at start up and injector clatter when cold) at about 50% retail price ...might yet take it.

If I was you check the exhaust back pressure pipe to sensor, clean out using brake cable or drill with cable attached. ,then look at EGRs and then dpf ...don't change injectors till last ...that was my issue ...I think changing injectors early on with refurbished ones where 7 character code may no longer match has caused a lot of issues

 

[MGrev]

Turbo improved it, put back in old injectors, improved it further, have one refurbished injector in it, going to swap out for used one, as I think these refurbed ones are not coded properly after they are rebuilt..I replaced the low pressure Egr and mesh wire gasket, as car was showing low pressure gas flow p0401 ...it now still shows same ...looks like blocked Egr cooler or crack in honeycomb in pdf ...have to have same looked at. But overall couldn't tell you what the exact issue is ..have offers on the car as it is(still smoking at start up and injector clatter when cold) at about 50% retail price ...might yet take it.

If I was you check the exhaust back pressure pipe to sensor, clean out using brake cable or drill with cable attached. ,then look at EGRs and then dpf ...don't change injectors till last ...that was my issue ...I think changing injectors early on with refurbished ones where 7 character code may no longer match has caused a lot of issues

Hi Mark, Did you find any solution of that issue? I have totally same story. Shaking after engine start, p0401, not enough power below 2000rpm and then big boost somewhere around 2000 rpm. Turbo checked by professionals, should be ok. Low pressure egr replaced, mesh replaced and cleaned, second egr cleaned, looks and works good. Yesterday I have replaced EGR cooler and tomorrow I fill in the coolant and do some tests but I have checked it on short way and probably no improvement. Already I have no idea what to do more, probably DPF is last thing to do... I'm already really tired of it.

 

[Mark1974]

No not solved but still have the car, drives great when warm, the p0401 is not affecting performance , haven't yet got to clean out low pressure egr cooler. Don't think it is causing the smoke or shake at start up. What I did notice is that the hi pressure egr on inlet side is opening immediately at start up, and not closing until low pressure egr opens at 55 degrees or above. Changed out high pressure egr , (having previously cleaned it) , got a second hand one ...Latvia or somewhere €30 , does exactly the same. Using xentry I can close it when car is started and smoke stops and shudder so the question is...why is hi pressure egr opening at start up? I believe it maybe somewhat controlled by intake actuator and intake air throttle , looking at them next ... but driving it daily and It passed nct (mot euivalent)

 

[Mark1974]

There is 1 other thing I noticed. In the cheap copy of xentry I have, the developer tab , seems to show 4 air intake temps (for the sensor built into the MAF) and also shows multiple different temps for the other sensor built into the MAP. Why it's showing 4 temps for the 1 sensor and 2-3 temps for the other sensor when each only records 1 temp ...I'm not sure...even stranger ...looking at the temp sensor built into MAF , 3 are equal and change (increase) when the car is running yet 1 always stays at -0.4C ..funnily this value is also shown and stays unchanged for the temp sensor built into the MAP for one of its 2-3 readings (you can only see it once here but further down it appears 2 more times and with correct temps) ...is it perhaps showing that one (of many Sam units or control units ) is actually reading air intake wrongly and hence thinks engine is cold.??? I'm probably way off. Within the non developer section and looking at the cdi unit both temps read perfectly fine but also have been replaced just to check (I've probably 2 of every sensor for this engine lol)

 

[MGrev]

I see, I have driven the car last 2 days and I have a feeling that it looks to accelerate better from lower rpm without sudden boost about 2000rpm, it is more smooth. I can't say more yet, because it'# only about 100km test. But still no EML and still no p0401. No shaking on cold engine start(only first start after replacing EGR cooler). I hope the issue is solved, but we will see

 

[MGrev]

Maybe try to clean this mesh,

 

[Mark1974]

I did and then I even replaced it,the mesh and low pressure egr and no joy on the smoke, shake or the p0401 disappearing ...ill keep going ...I think I have issues which are unrelated tbh

 

[Mark1974]

Unrelated but probably consequences ...e.g. putting in refurbed injectors where the codes were suss causing overfuelling/excessivd exhaust blocking low pressure egr quicker etc