SL 55 R230 - Acceleration Problem
Discussion
Hi Guys,
I wonder if anyone has experience this before.
After hard acceleration, if I step off the throttle for a couple of seconds and then floor it, the throttle stops responding.
Basically, the only way to get the car to respond is by pulling over and turning the engine off and restarting. I even had to physically remove the key from the ignition (usually the radio will turn off once the engine is turned off but in this case it would only turn off once the key was removed). Once I removed the key and then put it back in and switched the car on, the car was back to normal (albeit I didn't boot it again after that). I was scared that it would happen again, and although it might be psychological, it seemed to me that the car is not as responsive as it was before.
I have read similar issues on other forums where the goes into 'limp' mode. I do not believe that this is happening to me because after happening, the throttle does not respond whatsoever (whether at low RPM or high RPM).
Has anyone had this issue before? Is it a gear box problem? Or is it a failed sensor?
Any help would be greatly appreciated. Thanks!!
I wonder if anyone has experience this before.
After hard acceleration, if I step off the throttle for a couple of seconds and then floor it, the throttle stops responding.
Basically, the only way to get the car to respond is by pulling over and turning the engine off and restarting. I even had to physically remove the key from the ignition (usually the radio will turn off once the engine is turned off but in this case it would only turn off once the key was removed). Once I removed the key and then put it back in and switched the car on, the car was back to normal (albeit I didn't boot it again after that). I was scared that it would happen again, and although it might be psychological, it seemed to me that the car is not as responsive as it was before.
I have read similar issues on other forums where the goes into 'limp' mode. I do not believe that this is happening to me because after happening, the throttle does not respond whatsoever (whether at low RPM or high RPM).
Has anyone had this issue before? Is it a gear box problem? Or is it a failed sensor?
Any help would be greatly appreciated. Thanks!!
Sounds like it could be chargecooler pump, it's relatively common. If the pump stops working the charge air temps get too high (particularly during hard acceleration), so the engine management takes over to protect itself.
A Johnson CM30 pump is a common replacement rather than the stock Bosch one.
A Johnson CM30 pump is a common replacement rather than the stock Bosch one.
I had a similar problem with my SL55, and it turned out to be a faulty camshaft sensor. It is something I would never have suspected before hooking up to diagnostics.
About a year later, the same problem again, though this time the car would just become sluggish to respond,not go into limp mode. The accelerator pedal was the culprit, and a replacement sorted the issue. Supercharger pump is a also a likely culprit.
About a year later, the same problem again, though this time the car would just become sluggish to respond,not go into limp mode. The accelerator pedal was the culprit, and a replacement sorted the issue. Supercharger pump is a also a likely culprit.
Thank you very much for your replies gents, much appreciated.
So IC pump, throttle pedal and camshaft sensor. Are these expensive fixes and are any of these a possible diy job? Is it possible for me to identify the culprit beforehand? I had the car at a garage a few months ago and it didn’t through up any messages, although it is possible that this is a ‘new’ issue!
Cheers
So IC pump, throttle pedal and camshaft sensor. Are these expensive fixes and are any of these a possible diy job? Is it possible for me to identify the culprit beforehand? I had the car at a garage a few months ago and it didn’t through up any messages, although it is possible that this is a ‘new’ issue!
Cheers
Thank you very much for your replies gents, much appreciated.
So IC pump, throttle pedal and camshaft sensor. Are these expensive fixes and are any of these a possible diy job? Is it possible for me to identify the culprit beforehand? I had the car at a garage a few months ago and it didn’t through up any messages, although it is possible that this is a ‘new’ issue!
Cheers
So IC pump, throttle pedal and camshaft sensor. Are these expensive fixes and are any of these a possible diy job? Is it possible for me to identify the culprit beforehand? I had the car at a garage a few months ago and it didn’t through up any messages, although it is possible that this is a ‘new’ issue!
Cheers
As stated earlier the water pump used for the intercooler is the most common reason. This is located in the forward part of the drivers side wheel well behind the bumper. It is an easy enough DIY fix and is well documented.
When mine went I was able to give it the beans causing the sluggish behaviour. If I drove gently for a few minutes I could then go again and all was well for one blast and then repeat. I have a code reader that can access Mercedes subsystems if you are in the Midlands you are welcome to give it a try.
When mine went I was able to give it the beans causing the sluggish behaviour. If I drove gently for a few minutes I could then go again and all was well for one blast and then repeat. I have a code reader that can access Mercedes subsystems if you are in the Midlands you are welcome to give it a try.
Hi dapper dan,
Thanks very much for your response, and for your generousity. I live in the south east area so the midlands is a little too far for me, but thanks anyway.
I reckon I might try replacing the IC pump msyekf if it’s not too dear and seeing if that might be the problem. It’s probabky never been replaced and the car is 70k miles / 15 years old so it may well be worth doing anyway!
Thanks very much for your response, and for your generousity. I live in the south east area so the midlands is a little too far for me, but thanks anyway.
I reckon I might try replacing the IC pump msyekf if it’s not too dear and seeing if that might be the problem. It’s probabky never been replaced and the car is 70k miles / 15 years old so it may well be worth doing anyway!
It does sound like the chargecooler pump, mine failed on the slk32 at circa 9 years /75k.
The original Bosch (not sure about the upgraded) had a plastic impellor which over time disintegrated. The Johnson CM030 had a metal impellor, higher flow rate and was significantly cheaper plus had good feedback on all the merc forums so went with that
The camshaft sensor failing will usually result in the car cutting out completely and takes about 20 mins to start again. The sensor itself is circa £100 and a fiddly job to do as it's buried right in the engine and you need a specific tool for the job
The original Bosch (not sure about the upgraded) had a plastic impellor which over time disintegrated. The Johnson CM030 had a metal impellor, higher flow rate and was significantly cheaper plus had good feedback on all the merc forums so went with that
The camshaft sensor failing will usually result in the car cutting out completely and takes about 20 mins to start again. The sensor itself is circa £100 and a fiddly job to do as it's buried right in the engine and you need a specific tool for the job
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