Hesitation during acceleration with a twist
Thread Starter
Junior Member
Joined: Dec 2012
Posts: 16
Likes: 0
2000 Clk430
Hesitation during acceleration with a twist
I've read numerous threads with the same problems my 00 clk430 is having but not a single definitive solution.
The car hesitates when attempting to accelerate.. not the sight delay people speak of but a good 5 second delay between "flooring" it and it gaining speed. For example, at 55 if I step on it to overtake it revs between 3 and 4 thousand rpm and seems to be dropping down a gear however I'm sitting there as the car lags and experience a rubberband effect... waiting there for acceleration that doesn't come.
This is a recent event, the car used to be very snappy. The car currently has 93k miles and I replaced the MAF last year with the suggested Bosch..which corrected a check engine light issue I had at that time.
HERE'S THE TWIST.. I've read numerous posts stating this could be a vacuum issue, a maf issue, spark plug wire, catalytic converter...even one guy with a detailed explanation of sand in his engine. However, when I disconnected the battery and reconnected it the car accelerated as it used to for a week or so before again returning to the hesitation / lag issue. Therefore, it must not be a physical issue i.e. disconnected spark plug wire or crack in a vacuum hose. Also, again, it isn't a slight delay in response and has nothing to do with the adaptive throttle response.. This is a long, delayed sputtering hesitation when stepping on the gas.
So... disconnecting and reconnecting the battery corrected it for a period of time until it started hesitating again...any ideas?
The car hesitates when attempting to accelerate.. not the sight delay people speak of but a good 5 second delay between "flooring" it and it gaining speed. For example, at 55 if I step on it to overtake it revs between 3 and 4 thousand rpm and seems to be dropping down a gear however I'm sitting there as the car lags and experience a rubberband effect... waiting there for acceleration that doesn't come.
This is a recent event, the car used to be very snappy. The car currently has 93k miles and I replaced the MAF last year with the suggested Bosch..which corrected a check engine light issue I had at that time.
HERE'S THE TWIST.. I've read numerous posts stating this could be a vacuum issue, a maf issue, spark plug wire, catalytic converter...even one guy with a detailed explanation of sand in his engine. However, when I disconnected the battery and reconnected it the car accelerated as it used to for a week or so before again returning to the hesitation / lag issue. Therefore, it must not be a physical issue i.e. disconnected spark plug wire or crack in a vacuum hose. Also, again, it isn't a slight delay in response and has nothing to do with the adaptive throttle response.. This is a long, delayed sputtering hesitation when stepping on the gas.
So... disconnecting and reconnecting the battery corrected it for a period of time until it started hesitating again...any ideas?
Senior Member
Joined: Jun 2013
Posts: 287
Likes: 5
From: New Hampshire
Magma Red W208 55 AMG, W203 C230 Kompressor Sedan 6speed M/T, W220 S500
Research TPS .
It could be any one of the things you have stated. Have you looked into the bad catalytic converter theory?
It could be any one of the things you have stated. Have you looked into the bad catalytic converter theory?
Thread Starter
Junior Member
Joined: Dec 2012
Posts: 16
Likes: 0
2000 Clk430
I'm not sure how to diagnose that because I have no check engine light on. But, unplugging the battery could temporarily fix that? I figured if there was an issue with the cc that it wouldn't be electronic.
Senior Member
Joined: Jun 2013
Posts: 287
Likes: 5
From: New Hampshire
Magma Red W208 55 AMG, W203 C230 Kompressor Sedan 6speed M/T, W220 S500
When my TPS went out I would pull over and turn the car off and back on and it would work fine untill I went over half throttle again. It progressively became worse and eventually threw a CEL. Although without it making the CEL come on it still was readable with an OBDii reader, the code came up as pending.
The only way to figure it out short of bringing it to a professional is to go out there with some basic tools and narrow down your symptoms. Good luck and welcome to the forums.
The only way to figure it out short of bringing it to a professional is to go out there with some basic tools and narrow down your symptoms. Good luck and welcome to the forums.
Senior Member
Joined: Jan 2015
Posts: 389
Likes: 113
From: Seattle, WA
SL500
Another possibility is the EGR isn't opening as it should. There is both an EGR valve as well as an EGR control transducer. If the transducer is failing, then it can send a delayed signal to the EGR valve causing a lag in it opening, then when it finally does open -Vroom, sudden full power.
Also, if it hasn't been changed, then try changing your coolant temp sensor. It's a cheapy fix that's often overlooked, but like any other sensor, they do fail and that sensor is tied into your EGR & Throttle System. If you've never changed yours, spend the $15 bucks as a preventative maintenance measure and it just might be that simple.
Also, if it hasn't been changed, then try changing your coolant temp sensor. It's a cheapy fix that's often overlooked, but like any other sensor, they do fail and that sensor is tied into your EGR & Throttle System. If you've never changed yours, spend the $15 bucks as a preventative maintenance measure and it just might be that simple.
MBWorld Fanatic!
Joined: Apr 2005
Posts: 3,784
Likes: 84
From: SCV SoCal
2002 CLK430
A year ago I experienced a similar problem. The throttle response lagged behind the pedal actuation. If your problem is similar to mine, it will get much worse. The throttle actuation is electronically controlled and uses a pedal travel sensor. In my case, that part eventually failed. When that part completely fails, the throttle will still work, but with a huge delay. An ME 2.8 pedal travel sensor is part number 012-542-33-17 and in my case it did NOT throw a code. My local dealer was able to test and diagnose the problem in about 15 minutes. The 2000 and earlier cars use ME 2.0 so that $150 ($230 retail) part will not fit. You may wish to have a capable mechanic diagnose the issue.
Newbie
Joined: Jun 2016
Posts: 2
Likes: 0
2001 Mercedes s500
Poor acceleration
A year ago I experienced a similar problem. The throttle response lagged behind the pedal actuation. If your problem is similar to mine, it will get much worse. The throttle actuation is electronically controlled and uses a pedal travel sensor. In my case, that part eventually failed. When that part completely fails, the throttle will still work, but with a huge delay. An ME 2.8 pedal travel sensor is part number 012-542-33-17 and in my case it did NOT throw a code. My local dealer was able to test and diagnose the problem in about 15 minutes. The 2000 and earlier cars use ME 2.0 so that $150 ($230 retail) part will not fit. You may wish to have a capable mechanic diagnose the issue.
