C43 low on power, poor cold start, off-idle hessitation
Thread Starter
Senior Member
Joined: Feb 2017
Posts: 392
Likes: 9
From: Australia
W202 C43 1999
C43 low on power, poor cold start, off-idle hessitation
Hi all,
Got some issues with my 99 C43 / 5.4ltr.
First off, cold start is not real good, seems like its lean on fuel at start up, but only for the first start. If you shut it straight off then start again, its fine.
Secondly, it seems to have a bit of an off-idle hessitation that makes it difficult to drive smoothly at low speeds.
Third, there is a rattle at idle that goes away as soon as you touch the throttle, appears to be coming from timing chain, but cant seem to narrow the sound down to one side or the other. Does this with belt on or off.
Forth, it seems to be losing low down torque, up higher in the revs it seems reasonably good, not what it should be, but floor it off the line from a standing start id expect easy wheel spin, 18 months ago it would spin off the line at about 1/2-3/4 throttle.
If the traction control cuts power at low rpm for wheel spin, the power comes on very strong and seems a lot better than if it is a straight up punch the throttle with no traction control intervention, not sure why this is.
I have replaced the following items over the past 18 months:
- Timing tensioner
- plugs 40,000klms ago
- plug leads ( factory OEM kit )
- coolant temp sensor
- cam sensor
- crank sensor
- MAF ( 3 weeks ago, genuine OEM )
- intake manifold gaskets
- variable runner vacuum hose
- throttle body gasket
- rubber hoses between intake and rocker covers
- pedal position sensor
- rocker cover gaskets
- water pump
- fan clutch
- idler pulley
- tensioner pulley
- MAF intake elbow rubber seals
- fuel pump
- fuel filter
- radiator
- ESL
- O2 sensors ( genuine Bosch )
- Lateral accelorometer ( silver one in the boot )
- transmission electrical connector
There may be a couple other items i have replaced that ive forgotten.
I have not replaced coils or knock sensors, but coils have been removed and put back in different spots before with no change.
what could cause this thing to seem down on power the way it is? Could cam timing be out due to worn parts?
Got some issues with my 99 C43 / 5.4ltr.
First off, cold start is not real good, seems like its lean on fuel at start up, but only for the first start. If you shut it straight off then start again, its fine.
Secondly, it seems to have a bit of an off-idle hessitation that makes it difficult to drive smoothly at low speeds.
Third, there is a rattle at idle that goes away as soon as you touch the throttle, appears to be coming from timing chain, but cant seem to narrow the sound down to one side or the other. Does this with belt on or off.
Forth, it seems to be losing low down torque, up higher in the revs it seems reasonably good, not what it should be, but floor it off the line from a standing start id expect easy wheel spin, 18 months ago it would spin off the line at about 1/2-3/4 throttle.
If the traction control cuts power at low rpm for wheel spin, the power comes on very strong and seems a lot better than if it is a straight up punch the throttle with no traction control intervention, not sure why this is.
I have replaced the following items over the past 18 months:
- Timing tensioner
- plugs 40,000klms ago
- plug leads ( factory OEM kit )
- coolant temp sensor
- cam sensor
- crank sensor
- MAF ( 3 weeks ago, genuine OEM )
- intake manifold gaskets
- variable runner vacuum hose
- throttle body gasket
- rubber hoses between intake and rocker covers
- pedal position sensor
- rocker cover gaskets
- water pump
- fan clutch
- idler pulley
- tensioner pulley
- MAF intake elbow rubber seals
- fuel pump
- fuel filter
- radiator
- ESL
- O2 sensors ( genuine Bosch )
- Lateral accelorometer ( silver one in the boot )
- transmission electrical connector
There may be a couple other items i have replaced that ive forgotten.
I have not replaced coils or knock sensors, but coils have been removed and put back in different spots before with no change.
what could cause this thing to seem down on power the way it is? Could cam timing be out due to worn parts?
MBWorld Fanatic!
Joined: Mar 2005
Posts: 2,418
Likes: 194
From: America
1999 C43 AMG, 2005 E55 Wagon
I'm not sure about the timing being worn down causing that. My original 4.3 motor had 297k miles on it. The last 100k miles I barely maintained it and abused it relentlessly because I was just going to put a 5.4 in it so I had no reason to continue taking good care of it. I expected to kill that motor doing oil every 15k miles, full throttle launches and burnouts all the time. The timing chain had already started making a rattle at idle at around 230k miles, so it was kind of an experiment to see how much abuse the motor could take with all those miles.
I only did basic stuff to keep it running and abused it the entire time. At 297k miles it was still just as powerful. Was still getting to 60 a bit faster than the factory spec of 5.9sec. I went ahead and put a 5.4 in it anyway.
With all the wear my chain had, it didn't lose any power. I doubt your's has.
I only did basic stuff to keep it running and abused it the entire time. At 297k miles it was still just as powerful. Was still getting to 60 a bit faster than the factory spec of 5.9sec. I went ahead and put a 5.4 in it anyway.
With all the wear my chain had, it didn't lose any power. I doubt your's has.
Out Of Control!!
Joined: Feb 2003
Posts: 13,489
Likes: 96
haters crazy
Are there any codes? Do you have a wideband on the car? I don't think it's timing related unless you had the chain off recently to install cams or something. Those chains are pretty strong and I've never seen them skip a tooth
Thread Starter
Senior Member
Joined: Feb 2017
Posts: 392
Likes: 9
From: Australia
W202 C43 1999
No codes any time ive had it in to the workshop, but this being a Euro spec car there is no check engine light either.
ive not had the chain off at any point, i doubt its even been off.
ive not had the chain off at any point, i doubt its even been off.
Thread Starter
Senior Member
Joined: Feb 2017
Posts: 392
Likes: 9
From: Australia
W202 C43 1999
no, it wasnt seperated. If i hold my hand over the MAF while idling, the engine dies pretty quickly and does not seem to lose the vacuum very quickly there at all, even though my hand does not make a real good seal.
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MBWorld Fanatic!
Joined: Oct 2013
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From: New Jersey
1999 AMG C43
rattle is usually exhaust related. def check the codes even if there werent any codes last time. those vacuum leaks can be tough to find sometimes but spray around and see if you can find a crack or something
Thread Starter
Senior Member
Joined: Feb 2017
Posts: 392
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From: Australia
W202 C43 1999
The rattle sure seems to be coming from up the front more so than anywhere near the exhaust, but ill check that out.
All i read seems to suggest the chain guides are pretty much a life time part and dont really cause issues, the chains seem to be mixed opinions, there are lots saying that the chains are no issue, and just as many saying theyve found them stretched to buggery.
If the chain was stretched and cam timing was out, would this in turn directly affect spark timing? Is spark timing triggered by cam sensor or crank sensor?
Thread Starter
Senior Member
Joined: Feb 2017
Posts: 392
Likes: 9
From: Australia
W202 C43 1999
Would this rattling noise be causing timing retardation due to knock sensors picking it up?
If not the cam chain what else would cause this rattle that goes away with a 100-200 rpm increase?
If not the cam chain what else would cause this rattle that goes away with a 100-200 rpm increase?
Thread Starter
Senior Member
Joined: Feb 2017
Posts: 392
Likes: 9
From: Australia
W202 C43 1999
this is timing chain rattle.
https://www.youtube.com/watch?v=HvWwCEyWSx0
the video implies it's the harmonic balancer, but it was not. it was the chain (this is my car)
https://www.youtube.com/watch?v=HvWwCEyWSx0
the video implies it's the harmonic balancer, but it was not. it was the chain (this is my car)
MBWorld Fanatic!
Joined: Apr 2006
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From: Bay Area, CA
98 C43, 15 Alfa 4C LE, 18 Tesla Model 3 DM Perf, 08 Duc S1000, 02 Duc 998, 98 Duc 748, 01 Miata
Who replaced all of those components? When did you first notice this issue? I would think there is a higher likelihood of something not being installed correctly (versus a part you haven't changed failing) and it'd be easier to diagnose if we knew when this began relative to what components had been installed around that time. I would have gone with PJ with this being a MAF issue but there are a lot of variables going on here and you mentioned replacing the MAF recently. Honestly, if we can't figure it out pretty quickly, it'd probably be worth the money to pay the dealer or an independent for a diagnosis.
Thread Starter
Senior Member
Joined: Feb 2017
Posts: 392
Likes: 9
From: Australia
W202 C43 1999
Who replaced all of those components? When did you first notice this issue? I would think there is a higher likelihood of something not being installed correctly (versus a part you haven't changed failing) and it'd be easier to diagnose if we knew when this began relative to what components had been installed around that time. I would have gone with PJ with this being a MAF issue but there are a lot of variables going on here and you mentioned replacing the MAF recently. Honestly, if we can't figure it out pretty quickly, it'd probably be worth the money to pay the dealer or an independent for a diagnosis.
The issue started coming up before i had the intake manifold gaskets replaced by a workshop with brand new genuine Merc parts. When they did this, they pulled the vac hose out for the variable intake flaps and replaced it with one that was too small to fill the hole, against my advice. They sealed around that with silicone, which made the car run perfectly smooth for about a week. They then took the manifold back off and replaced the hose with a much fatter one, and sealed around that, although apprently the hose is a snug fit. The issue has been there since just after this.
MBWorld Fanatic!
Joined: Apr 2006
Posts: 1,101
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From: Bay Area, CA
98 C43, 15 Alfa 4C LE, 18 Tesla Model 3 DM Perf, 08 Duc S1000, 02 Duc 998, 98 Duc 748, 01 Miata
I replaced the majority of them, and theyve all been checked a few times, theyre done right. I did 11 years working on Corvettes and made quite a few of those run smoothly.
The issue started coming up before i had the intake manifold gaskets replaced by a workshop with brand new genuine Merc parts. When they did this, they pulled the vac hose out for the variable intake flaps and replaced it with one that was too small to fill the hole, against my advice. They sealed around that with silicone, which made the car run perfectly smooth for about a week. They then took the manifold back off and replaced the hose with a much fatter one, and sealed around that, although apprently the hose is a snug fit. The issue has been there since just after this.
Thread Starter
Senior Member
Joined: Feb 2017
Posts: 392
Likes: 9
From: Australia
W202 C43 1999
The intake manifold had to come back apart to replace with the fatter hose, correct? Did they replace the seal that time? This thread seems to have a lot of information about this particular topic: http://www.benzworld.org/forums/w163...questions.html
MBWorld Fanatic!
Joined: Aug 2006
Posts: 7,053
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From: A.D., U.A.E
2000 (W202 C200) & 2000 (W202 C55)
Did you try to diagnose the car while driving it..?,,
it may helps to narrow the issues,
last month, i did swap for my friend, we forced losing power at high idle,
diagnose the car so many times, no codes founded..!,,
after that, we decided to diagnose the car while driving, after around "10" minutes, ECU deducts wrong signal back from knock sensor bank [2/R]..?!?!,,
replaced the two knock sensors, bingoooooooo, everything comes sooo great..
-;ZAYED;-
it may helps to narrow the issues,
last month, i did swap for my friend, we forced losing power at high idle,
diagnose the car so many times, no codes founded..!,,
after that, we decided to diagnose the car while driving, after around "10" minutes, ECU deducts wrong signal back from knock sensor bank [2/R]..?!?!,,
replaced the two knock sensors, bingoooooooo, everything comes sooo great..
-;ZAYED;-
Thread Starter
Senior Member
Joined: Feb 2017
Posts: 392
Likes: 9
From: Australia
W202 C43 1999
Did you try to diagnose the car while driving it..?,,
it may helps to narrow the issues,
last month, i did swap for my friend, we forced losing power at high idle,
diagnose the car so many times, no codes founded..!,,
after that, we decided to diagnose the car while driving, after around "10" minutes, ECU deducts wrong signal back from knock sensor bank [2/R]..?!?!,,
replaced the two knock sensors, bingoooooooo, everything comes sooo great..
-;ZAYED;-
it may helps to narrow the issues,
last month, i did swap for my friend, we forced losing power at high idle,
diagnose the car so many times, no codes founded..!,,
after that, we decided to diagnose the car while driving, after around "10" minutes, ECU deducts wrong signal back from knock sensor bank [2/R]..?!?!,,
replaced the two knock sensors, bingoooooooo, everything comes sooo great..
-;ZAYED;-
Did the knock sensor code go away after turning off the engine?
what is the part number for the knock sensors?
MBWorld Fanatic!
Joined: Aug 2006
Posts: 7,053
Likes: 398
From: A.D., U.A.E
2000 (W202 C200) & 2000 (W202 C55)
We drove the car without hood, for a while..
,,
i think, there's a "Bluetooth" port conversion, but not that sure about it..!,,
there wasn't code for knock sensor, but after driving, ECU catch the fault back signal from know sensor, and suddenly, code appears then vanished, it was "P1386"..!?!?,,
we stopped the car, diagnose the car again, no codes,,
after that, replaced the knock sensors, NO issues then..
i used knock sensors from "M156" Engine;-
*OEM # "004 153 90 28"
*Bosch # "0 261 231 188"
-;ZAYED;-
,,i think, there's a "Bluetooth" port conversion, but not that sure about it..!,,
there wasn't code for knock sensor, but after driving, ECU catch the fault back signal from know sensor, and suddenly, code appears then vanished, it was "P1386"..!?!?,,
we stopped the car, diagnose the car again, no codes,,
after that, replaced the knock sensors, NO issues then..
i used knock sensors from "M156" Engine;-
*OEM # "004 153 90 28"
*Bosch # "0 261 231 188"
-;ZAYED;-
Thread Starter
Senior Member
Joined: Feb 2017
Posts: 392
Likes: 9
From: Australia
W202 C43 1999
We drove the car without hood, for a while..,,
i think, there's a "Bluetooth" port conversion, but not that sure about it..!,,
there wasn't code for knock sensor, but after driving, ECU catch the fault back signal from know sensor, and suddenly, code appears then vanished, it was "P1386"..!?!?,,
we stopped the car, diagnose the car again, no codes,,
after that, replaced the knock sensors, NO issues then..
i used knock sensors from "M156" Engine;-
*OEM # "004 153 90 28"
*Bosch # "0 261 231 188"
-;ZAYED;-
,,i think, there's a "Bluetooth" port conversion, but not that sure about it..!,,
there wasn't code for knock sensor, but after driving, ECU catch the fault back signal from know sensor, and suddenly, code appears then vanished, it was "P1386"..!?!?,,
we stopped the car, diagnose the car again, no codes,,
after that, replaced the knock sensors, NO issues then..
i used knock sensors from "M156" Engine;-
*OEM # "004 153 90 28"
*Bosch # "0 261 231 188"
-;ZAYED;-
What was your reason for using the M156 knock sensors?
Does anyone have any info on any sort of diagnostic equipment i can buy for a Euro spec car that will allow me to check most modules?
Are there any around that i can make changes to the settings within the ECM?
