New (to me) C32 AMG - acceleration issues?!? - help!
I've read and enjoyed a lot of your threads (and pics) of your C32's. Might need a little help with mine - please offer any insights you may have!
I recently purchased a 2004 C32 w/ extremely low miles (19K when I picked it up, a little over 20K now). Car itself is in great condition - appears to be completely stock at this point. Black over charcoal, COMAND, bi-xenon's, heated seats, etc. - it's loaded, everything except the phone (which I prefer my cars not to have anyway). Car's still under factory warranty until mid-Feb 2008.
Anyway, I've noticed that, at times, the acceleration of the car is TERRIBLE. Recently, on the highway, I was following some P.O.S. (Kia maybe?), light traffic, about 75-80 mph. In our lane ahead a mattress had fallen off of a truck, and we both had to come almost to a complete stop on the highway to avoid it (probably down to 10-15 mph). I'm in drive, sport setting, ESP on, don't bother to manually downshift but I just move over an extra lane and mash the gas to get around the Kia. And - wait for it - the car started accelerating like a complete pig (the Kia was actually getting up to speed faster!). It literally felt like it had no power at all. Eventually, I got back up to speed, so no big deal - but I was a little concerned obviously. I've read in some of these threads that a similiar problem can happen when the intercooler pump fails, but is this a problem w/ 2004s, especially w/ only about 20K miles?
The car is due for a "B" service soon anyway, so I intend to mention it to the dealer, but anything you might add would help me be better prepared in advance - thanks!
I've read and enjoyed a lot of your threads (and pics) of your C32's. Might need a little help with mine - please offer any insights you may have!
I recently purchased a 2004 C32 w/ extremely low miles (19K when I picked it up, a little over 20K now). Car itself is in great condition - appears to be completely stock at this point. Black over charcoal, COMAND, bi-xenon's, heated seats, etc. - it's loaded, everything except the phone (which I prefer my cars not to have anyway). Car's still under factory warranty until mid-Feb 2008.
Anyway, I've noticed that, at times, the acceleration of the car is TERRIBLE. Recently, on the highway, I was following some P.O.S. (Kia maybe?), light traffic, about 75-80 mph. In our lane ahead a mattress had fallen off of a truck, and we both had to come almost to a complete stop on the highway to avoid it (probably down to 10-15 mph). I'm in drive, sport setting, ESP on, don't bother to manually downshift but I just move over an extra lane and mash the gas to get around the Kia. And - wait for it - the car started accelerating like a complete pig (the Kia was actually getting up to speed faster!). It literally felt like it had no power at all. Eventually, I got back up to speed, so no big deal - but I was a little concerned obviously. I've read in some of these threads that a similiar problem can happen when the intercooler pump fails, but is this a problem w/ 2004s, especially w/ only about 20K miles?
The car is due for a "B" service soon anyway, so I intend to mention it to the dealer, but anything you might add would help me be better prepared in advance - thanks!
90% chance it's your intercooler coolant pump. It's a simple pump and the dealer must replace it (under warranty). When it's broken, the intercooler is nonfunctional, and when the intake air gets too hot, the computer shuts off the supercharger, making your 350HP engine into a 185HP wheeze-bag.
Fortunately, my previous owner purchased the Mercedes-Care extended warranty for an extra 48 months and 100k miles (Premium coverage)! So I'm covered up until mid 2009!
Good luck!
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I've also noticed an EXTREMELY slight drivetrain "jerk" or "surge" @ highway speeds, that I'm pretty sure isn't a shift. I've read that some cars have a problem with this b/c of a bad radiator and contamination of their tranny's fluid (particularly '02s), but I'm guessing that mine might just be a "normal" side-effect of the supercharger clutch engaging or disengaging. I wonder a bit if the M-B (and AMG) engineers outsmarted themselves a bit with the whole "supercharger clutch" idea - I realize it helps gas mileage when just cruising along (right? isn't that the purpose?) but if it causes some weird mechanical and/or operator issues, I'm not sure if maybe "simpler would've been better." I don't have those same kind of surges w/ my '02 C230K Coupe - but it's also a 6 spd manual, so there're several factors that might make the difference...
Anyway, thanks again everybody - I'm looking forward to the day when I pull the trigger on an upgrade or two... any thoughts on getting headers (Supersprint, evosport, Kleemann, etc.) first, and then next summer sometime going w/ something like Renntech's Stage I (ECU and pulley) upgrade? I'm just thinking that, if my car's out of warranty then anyway, might as well upgrade then instead of now. Thoughts/comments? Thanks!
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I've also noticed an EXTREMELY slight drivetrain "jerk" or "surge" @ highway speeds, that I'm pretty sure isn't a shift. I've read that some cars have a problem with this b/c of a bad radiator and contamination of their tranny's fluid (particularly '02s), but I'm guessing that mine might just be a "normal" side-effect of the supercharger clutch engaging or disengaging. I wonder a bit if the M-B (and AMG) engineers outsmarted themselves a bit with the whole "supercharger clutch" idea - I realize it helps gas mileage when just cruising along (right? isn't that the purpose?) but if it causes some weird mechanical and/or operator issues, I'm not sure if maybe "simpler would've been better." I don't have those same kind of surges w/ my '02 C230K Coupe - but it's also a 6 spd manual, so there're several factors that might make the difference...
Thanks!
The tranny "jerk" is not at highway speeds. You're experiencing supercharger shut-down.
As to the modifications, keep in mind that you are quite possibly voiding your VERY valuable warranty if you make significant performance upgrades.
I've also noticed an EXTREMELY slight drivetrain "jerk" or "surge" @ highway speeds, that I'm pretty sure isn't a shift. I've read that some cars have a problem with this b/c of a bad radiator and contamination of their tranny's fluid (particularly '02s), but I'm guessing that mine might just be a "normal" side-effect of the supercharger clutch engaging or disengaging. I wonder a bit if the M-B (and AMG) engineers outsmarted themselves a bit with the whole "supercharger clutch" idea - I realize it helps gas mileage when just cruising along (right? isn't that the purpose?) but if it causes some weird mechanical and/or operator issues, I'm not sure if maybe "simpler would've been better." I don't have those same kind of surges w/ my '02 C230K Coupe - but it's also a 6 spd manual, so there're several factors that might make the difference...
Anyway, thanks again everybody - I'm looking forward to the day when I pull the trigger on an upgrade or two... any thoughts on getting headers (Supersprint, evosport, Kleemann, etc.) first, and then next summer sometime going w/ something like Renntech's Stage I (ECU and pulley) upgrade? I'm just thinking that, if my car's out of warranty then anyway, might as well upgrade then instead of now. Thoughts/comments? Thanks!
I've heard that, even if you do some upgrades, they can't void your warranty on unrelated stuff - and the burden of proof is on them to show that your upgrades DIRECTLY caused the failure - if so, then your on your own. Seems though from reading this message board that these engines (aside from a couple minor known issues) are pretty bullet-proof when it comes to adding 50-70hp through a couple bolt-on upgrades... agree?
Did you get problem sorted out and if so was it the I/C Pump? I would really appreciate some advise before I take it to the dealers as I have no warranty.
Did you get problem sorted out and if so was it the I/C Pump? I would really appreciate some advise before I take it to the dealers as I have no warranty.
FYI, there's a thread on a cheap replacement idea using the pump from a Ford Lightning (apparently it's the same pump, slightly different wiring harness, and a fraction of the price of the MB part) - so if you're mechanically inclined, you might want to check out that thread. Good luck!
Did you get problem sorted out and if so was it the I/C Pump? I would really appreciate some advise before I take it to the dealers as I have no warranty.
That's precisely the symptom.
The garage has just phoned up and have said that it is the intercooler pump and as a bonus I will only have to pay half the cost as the garage kindly has spoke to Mercedes and told them that my car had just been serviced by them prior to it going faulty and that they think that it should not of gone faulty.
I am very happy with the service I have got from my dealer they have genuinely tried to help me and save me money, which seems like a rarity according to some of the post I have read regarding the merc dealers.
Maybe they are changing there ways now.
Anyway I get my car back tomorrow and it should be as fast as hell again!!
I have learnt one thing with this problem and that is I will never be able to own a "normal car again" once being used to the power of an AMG!!
Last edited by sunnyk; Jun 12, 2007 at 10:44 AM.
The garage has just phoned up and have said that it is the intercooler pump and as a bonus I will only have to pay half the cost as the garage kindly has spoke to Mercedes and told them that my car had just been serviced by them prior to it going faulty and that they think that it should not of gone faulty.
I am very happy with the service I have got from my dealer they have genuinely tried to help me and save me money, which seems like a rarity according to some of the post I have read regarding the merc dealers.
Maybe they are changing there ways now.
Anyway I get my car back tomorrow and it should be as fast as hell again!!
I have learnt one thing with this problem and that is I will never be able to own a "normal car again" once being used to the power of an AMG!!
There's also some kind of control module involved in the S/C mix. They replaced mine,... but I'm not exactly sure what role it plays. We all know what the pump does,... but the module's role in the process is well beyond my understanding.




