gt4awd

So I'm leaving the mall, and go to push the gas while idle cruising around 5MPH. Instantly the car starts to die out. Horrible low RPM idle until engine eventually shuts down. Try to start the engine multiple times at first would start with very rough low idle and die out in 10-20 seconds. Lastly would just crank no start. After several hours go back to vehicle, and it starts up seems to be idling better. Go to hit the throttle and it responds at first. Then it does not respond to any input. Also at this point have the intake system off, and could hear a whine sound never present before when the throttle was working and reving up slightly.

Upon getting back to vehicle after the few hours I immediately scanned it with no pending codes. No CEL of course. After running it the P0120 shows up as a pending. Not sure what to do at this point. Replace the throttle assembly or take to dealership to be STAR scanned... This C32 has been the biggest POS ever. Repaired, and replaced so much on it. Can't get over two or three months without another component failing.

C32maximus

Code P0120 does suck the life out of many C32 owners. I have gone through it and I wouldn't be surprised if it comes back again.

Do get the car scanned on a star system and ask for the printout. Gives more information then a standard code scanner. It is worth the cost at this point. Just do the parts replacing yourself or at an independent.

I always travel with my OTC code scanner so I can read and erase codes.

gt4awd

The whine sounds is definitely coming from the throttle body. Noise is when throttle works and is pressed rapidly. This sound was never present before. So question is can a bad tps cause the throttle body to make this type of sound or is it 100% for sure the throttle body due to the sound being an indicator? Went back to the c32 today starts and runs but after blipping the throttle a few it stops responding. CEL also set instead of pending.

FrankW

Check the plug on your throttle body, replace the sensor on the pedal...

Throttle body is just a valve, it doesnt create any noise. The twin screw when vacuuming air into the engine creates a whine.

gt4awd

It's not the supercharger... That I know for a fact as I've ran the engine shortly without intake system on. I put the intake back on as well as could clearly hear the "suction" type sound originating directly from TB area. Maybe "whine" is a bad description. It sounds like air suction. Such as the plate not opening enough to allow the proper air flow? Did check the plug, and also TPS reset. Neither helped.

c32kompressor

You should check out my thread called all c32 owners. It describes this issue

gt4awd

Checked your thread, and that unfortunately wasn't the case... The throttle body makes it's usual electrical sound in pos 2 as well. Cleaned the connection with CRC, and pressed it on tight. Didn't help any. Just got back to the house after two hours spent in process of towing the C32. Same deal as before. Starts and runs with good idle at first and responds to throttle. After a minute no throttle response. If I keep starting it back up eventually rough idle, and stalling. c32kompressor, did you have the sound I describe coming from your throttle body when it was acting up or anyone who replaced TPS with successful results?

Wilsophia

How about the Throttle cleaning?

gt4awd

The splitter is covered in oil, so maybe that over the years has built up a gunk which is causing the throttle plate to stick at idle, and then the ECU cuts all throttle input for safety? Engine response is normal when reving, and will continue to stay reved as I got the coolant to 40C at 2k RPM while occasionally adjusting throttle up/down. Strange though because other than a slightly rough idle I had no issues. Then all the sudden it just dies on me...

Wilsophia

I have a cold idle stall problem, after clen throttle, it solved
https://mbworld.org/forums/c32-amg-c...hen-stall.html

91RS

Can you use a mirror or something and see if the throttle body is dirty?

Wilsophia

remove the Y pipe can see everything, quite easy job.

gt4awd

I have no doubt the throttle plate is dirty. However, can that alone cause the symptoms I have described? Good old work for the past two days and tomorrow, so I haven't had a chance to do anything with the C32. Head out at 3AM to clock in a 4AM and work until 3 to 5PM... Really hoping I can solve this issue without dishing out a lot of $$$. After all I've been through and the massive amounts of cash put into this C32 think I have no choice but to sell it. Can't keep going through these problems every 1 to 3 months especially with my unforgiving job when it comes to missing days regardless of the circumstances.

Wilsophia

In this situation, you can only try and try

gt4awd

I have looked at the throttle body/plate multiple times. It is far dirtier than the photographs show on yours. Really hope cleaning it will solve the problem. Did you end up getting a new gasket, or just reuse the old one? Connection cleaning didn't help any, and the harness stays tight in place, so I know that isn't the problem.

gt4awd

So, I'm searching online, and gathering information on what can cause a "suction" sound at the throttle body. There's a few suggestions. EGR valve... I have never checked this, nor cleaned it, and don't know where it's located on our engine? Vacuum leak... Looked at vacuum lines in the area of TB didn't notice any disconnected or cracked. Is there a line that connects to the TB underneath or something? IAC, Idle Air Control, do we even have this on our engine?

gt4awd

The suction sound was caused by a piece of paper towel stuck in the throttle body... I had plugged the intake inlets once the car died out at the mall. One managed to fall back there, and thankfully didn't make it through the TB got stuck on the plate. So, no more P0120, no codes at all, but now I'm leaning towards the crank position sensor being bad. After cleaning the TB car started up, and reved no problems. No hesitation/stalling at idle. I let the engine warm up, shut it off, and went back down to test drive. The engine would not start. Just cranks with no fire up. Now it will not start at all. Does this sound like CPS?

southernwake

It sounds like CPS to me, my car died on me at a red light and after about 20 minutes it fired back up and I was on the way to the shop and a few minutes later it died again, I could turn it over and over but it would not fire. Popped the hood waited 15-20 minutes and it started up. Died 3 times and finally had to push it to the shop since it dies about a block away. Hooked the car up and it was the CPS, which is what I had already gathered. Hopefully changing that out will solve your problem.

gt4awd

Got it diagnosed, and of course the luck I have had with this car continues. The shop says fuel pumps are out... $2,000 just for a new tank assembly. Is there any other options here for finding low mileage used tank, or something???

gt4awd

I'm not buying the whole tank needs to be replaced. What about sourcing a replacement pump such as this?

http://www.autopartswarehouse.com/de...QQBS67974.html

Also, is this diagram correct for the C32?

320 dreamer

stockton auto dismantlers has a 2003 fuel tank for 350$

splinter

That’s a big red flag. Have you or they verified pressure at the rail?
Received your PM. If you send another with your VIN, I’ll look up the PN(s) for pump replacement (might also be useful for aftermarket cross-reference).

https://mbworld.org/forums/c32-amg-c...p-bad-c32.html

gt4awd

320 do you know if 2003 fuel tank will work on 2002? I would assume so but with Mercedes who knows... Not even sure if I have the 4-pin connector or not. Car is still sitting at the shop.

I will get more in-depth with the shop owner once I go to get her towed back. From what he said manually connected 12v supply to pump, and tapped it with a hammer??? few times. Car would start and run for 15 minutes, and then die out. Says the pump is bad... When I get the vehicle back will send another PM with VIN. Thanks splinter!

SYZYGY

I had the same diagnosis, same price too- right around $2200 is what I paid, however, they did not replace the tank. They replaced the sender unit and the fuel pump assembly.

03MBC32

The Star DVD indicates the MB part number for the pump is 203 470 13 94.

Edit:
The C32's fuel pump is made by PIERBURG as far I know.