Hello all,
I'm very happy and proud to be a part of this forum as I have recently purchased a 2003 C32 Amg Silver/Black, that came with the Code 3 Pulley and Intake, and (so previous owner states: ) johnson pump. I was torn between an e46 M3 and this car and ultimately decided that the AMG was the better match(I need 4 doors and I'm not a *****). I absolutely love the car and have found an amazing forum here; it seems to be a different kind of buyer than some of the other forums I have visited in the past. This is my first post and I promise that I followed the rules of etiquette and used the "search" feature before posting this: Here's my issue. On the drive home from purchasing my C32, I noticed the power seemed to be amazing, then after getting gas, the power was missing suddenly, gas pedal didn't want to respond much (takes a while for rpms to build). After another stop for dinner, and stopping the vehicle for about an hour, the power was back and everything was fine. The car didn't do this again for about 3-4 days, then suddenly same thing again. I researched on this forum and read about possible TPS, or IC Pump. I was too busy to dive in at the time and figure it out, and it was very intermittent (fine 3 days, no power 1/2 day, fine 3 days, etc.) I quickly realized that shutting the car off and turning it back on would sometimes make everything function as it should (supercharger working, it seems that the supercharger goes into safety mode and turns off when the problem occurs). Later the CEL came on after shutting on/off and I drove to an advance auto parts to get the codes read. p0120, throttle position sensor. No other codes. So I read the forum and ordered a throttle pedal assembly from Mercedes. $160, easy install (10 mins). A few days before the pedal came in the mail, the idle became erratic, supercharger would turn off, and the gas pedal seemed to have really strange inputs as the car would want to accelerate slightly even if you weren't pressing the pedal (it was really aggravating driving anywhere) , I thought , "well at least this confirms it, its the gas pedal assembly and not something else.." So I install the gas pedal, car runs great, idle is fine now, yet, the same initial problem is still there: random power loss/no supercharger, about once every other day now. Since the CEL was still on, I ran to advance to get the codes read again and now I have new ones: p0120 TPS, p0303 cylinder 3 misfire, p0306 cylinder 6 misfire, p0302 cylinder 2 misfire, p0105 Manifold Absolute Pressure/Barometric Pressure Circuit Malfunction p0300 random multiple cylinder misfires. I reset the CEL and I purchased NGK iridium IX that are mentioned on this forum. Just finished installing those (that last spark plug on the drivers side is a PITA!), drove down the highway, and power went away again. I pulled over, shut off/on. CEL now back on. What's really strange is the the power loss can happen after driving the car for 3 minutes without accelerating hard at all, which makes it hard for me to believe that it is the intercooler pump (wouldn't i need high IATs for the pump to be the problem?). I've also driven the car pretty hard and had no issues before. I'm at a loss, I love working on the vehicle and diagnosing and fixing everything myself (by this I mean without being raped at ANY mechanics shop or a stealership, where I live there are some shady mechanics that think Euro Import Owner = sucker), so I'm seeking any help from all you MBWORLD amg fanatics out there, sorry for the long description , any and all help greatly appreciated.
What do you think?
Intercooler pump?
spark plug wires?
loose connection somewhere?
praying its not a supercharger issue
couldn't have 2 bad TPS in a row right?
HELP!, Thanks!,

 

I think you have a few current problems. Yes, the intercooler pump is likely going bad. That is causing your power loss. I think you also have a vacuum leak due to your description. That is causing your other issues including CEL.

 

I hope you figure out the problem. I'm in a similar situation, and have even made a similar post a while back about it. When i first bought my C32 it ran smooth and was VERY quick. Well the car had some issues i was working on and the car sat for a very lon time. Now the car bogs down and hesitates and doesn't have the power it use to. I've only put a few hundred miles on it in my first year of ownership

Anyways, i can't answer your question,but i wish you the best. You can also check your IC pump behind the pass. fog light to see if it is in fact a Johnson.

Oh and i've read a few threads on this forum very very similar to yours in the past. If you search hard enough you may be able to find them.

 

I had similar problems and it was my MAF. Replaced and was good as golden....

 

I thought the C32 did not have a MAF sensor, but it has a MAP sensor??? I am having hesitation problems too still as well as sluggish shifts and jerking.

 

REFLEX92, how did you go about resolving the issue? What parts did you end up ordering? I'm with alkrstev about the MAF, I thought that the supercharged v6 and v8 amg's had MAPs and the N/A amg's had MAFs.... I'm going to check on the vacuum lines and if that's not it I'd be ecstatic if the MAF sensor replacement will take care of this.... Also wonder if its possible to just clean the MAP like others have cleaned there MAFs..... Some days I have 385 crank HP, and some days I don't.... Also its kinda scary passing a car when you don't know if the power is there or not......Thanks again for all the replies.

 

Hey DerHammer,
I had a nitrous backfire and it blew the cat up. The car went into limp mode and I had to pull over and reset the ecu. I thought I blew the car up. I checked with my scan tool and it said multiple cylinder misfire and also the whole right side bank misfire. The car had a totally different exhaust tone. I pulled the cats off and checked an the right side was broken apart... I know your not spraying nitrous but maybe you had some kinda backfire and broke the cat apart.. I hope this helps
Kevin

 

GT4AWD, I just checked the intercooler pump, to my surprise the seller of the vehicle was honest, CM30 Johnson! I really don't think the Johnson is already going bad after 15000miles. For anyone else reading with similar problems I found a vacuum line that may or may not be my culprit, but could be yours : its under the driver's side airbox where the rear mount for the airbox rests, little tube has very little keeping it in place, mine was loose but not free, so i'm not sure if that was my problem yet, I'm trying to find a diagram or instructions on locating the MAP and seriously thinking about going ahead and ordering one,
Mike

 

Let me know how it goes, you're describing exactly what I'm experiencing (except I've never gotten any codes, nor have the CEL come on), and my mechanic couldn't find any issues with my car. (just bought it, lost power occasionally on the drive home).
I've put 1000 miles on it after I bought it, and some days it runs like normal, while other days it can lose power right after a cold start, but if I restart the engine, it will run normally again, then lose power at random.

How do I check if the IC pump is running by the way? Just physically touch it and feel for vibrations, or is there another way?

 

With the hood open turn the car on for a minute, turn the car back off and quickly go to the passenger side wheel-well to see if you hear the pump running. It usually runs for 5-10 seconds after shutting off engine.

 

You would be surprised how often these pumps go bad. Yes, even the Johnson can and I'm sure has failed at 15,000 miles. Although it is known to be more reliable than the Bosch unit. There's a vacuum line that connects to the supercharger passenger side. You can see it between the intake manifold, and throttle body. This came loose on my C32 once, and caused MAP CEL. I suggest even without a CEL scan OBD for pending codes. I get a strange one in dyno mode that cuts out the supercharger. Incorrect Gear Ratio - Pending Code. It's strange because the problem only occurs in dyno mode.

 

No sound at all. The pump runs damn hot though, almost burns my finger when touching it. Maybe this is because it's not circulating the fluids?

 

Likely normal due to the fact you're still running the stock intercooler configuration. Separation of the engine coolant and intercooler system helps a lot to reduce intercooler fluid temperatures.

 

I'm really stuck here. My mechanic tells me to come back with the car while it is happening, but the thing is it's so on and off, I can lose power in one intersection and have it back the next. I have no idea how to attack this problem at the moment other than taking it to a stealership, which I kinda don't wanna do.

 

Sounds like your throttle body to me. It took a while for me and my mechanic to diagnose the problem. Multiple CEL codes, but consistently pointed to the Throttle body. I was hoping it was my pedal sensor(which was one of the codes) but I had my Throttle body rebuilt and now all is gravy!

Find a good reputable indy mechanic and go from there.

Got my Throttle Body rebuilt by BBA Remanufacturing, $400 plus two week turnaround time.

http://bba-reman.com/uk/index.aspx

Good Luck!

 

Any news about the issue Derhammer?
For me it had totally disappeared for over a week now, until today when it happened 4 or 5 times within 5 minutes. It's so strange cause you can hear the engine rev up, but it just seems like it refuses to put almost any power at all to the wheels. Almost like driving a manual transmission with the clutch half way in. Starting to doubt it's the intercooler pump here, although it runs terrible warm. If I touch the reservoir where the cooling fluid is, it's burning hot.

 

Sorry for the late response, yes the Mercedes guy told me it was the MAF and when I picked up my car I had all my power back. He ALSO said he fixed a IC leak.....**** maybe I just go dig up that invoice and see what the hell really went on.....LOL

 

This is bizzare...C32s do not have MAFs.

 

Apox,
Sorry I've been away from the forums for a little bit, funny how that happens when the car runs like it should! I'm not exactly sure which fix worked for me: spark plug replacement, new gas pedal assembly, or fixing the loose vacuum line, but nothing changed until I reset the battery for 30 minutes(disconnect negative terminal). My check engine disappeared and the car runs like a bat out of hell all the time now. No more power loss, no more hesitation, I clocked my 0-60 around 4.4 with a GPS application for android smartphones. Not sure if thats accurate, but it sure FEELS accurate. I spent a lot of time driving hard with a friend of mine who owns a 2004 m3 coupe 6-speed -sunroof. He wanted to race me until I let him drive the AMG. The only issue that remains is that if I absolutely floor it from a stop with the ESP still on, the car sometimes goes into limp mode with the message "ESP malfunction: Please visit workshop" With ESP off, this doesn't seem to happen from what I can tell. I'm curious as to whether or not this is a common occurrence with C32's. Now I'm anxious to order the Eurocharged Heat Exchanger, Needswings intercooler separation kit, magnecor KV85's, and Eurocharged Tune next month. I know this is probably a question for another thread but I'll ask anway: I want more power and I already have the Code 3 pulley and intake, should I just leave this pulley in place and get a tune, remove this pulley and order a 185 pulley then tune, or stack a 178 pulley and tune? I think I remember reading bad things about the pulley combo, but that the white Eurocharged c32 had a stack..... Anyway, I'm absolutely loving the car, I'm trying to sell both of my 5-series sedans to get another AMG product at the moment...
btw I test drove a clk55 cabriolet w208 yesterday and was completely underwhelmed with the power after driving my c32 with code 3..... the clk felt really slow...i'm wondering if it didn't have some kind of issue limiting its performance...

 

I don't think I've ever had the esp mode come on and put my car in to limp mode. I've actually never experienced limp mode.

 

I got new plugs and a new gas pedal assembly, but still have hesitation. Can you tell us which vacuum line you tightened please so i can check too.

 

alkrstev,
There is a small blackish vacuum line that connects beneath the driver's side airbox. It is easy to disconnect this line when placing the airbox back into position. I tried to illustrate where I found my vacuum line in the attached picture.

 

thanks derhammer. i will take a look at that tomorrow. i hope thats the problem.

 

alkrstev,

I wish you the best of luck, I know how aggravating it is to have a car with amazing performance that is intermittent at best. BTW, I never had sluggish shifting at all, I'm afraid your problem may be different.

 

When you lost power, did it feel the same like it does on my car: Like you're driving a manual with the clutch half way in? I mean, the engine sounds normal, the supercharger whine is heard, but it just refuses to put as much power to the wheels as before. Kinda starting to think it's the transmission.
I've also started having it idle at 2000rpm right after a coldstart, don't know if this is normal. It goes down to under 1000 after like 10 seconds though So I'm guessing it's not a big deal.