C250 Problem... suggestions?

"Firewrx234" (firewrx234)
03/21/2016 at 16:21 • Filed to: C250

So I’m going to start off by saying I have no CEL but something is definitely awry.

While driving home, Itried to tap the gas pedal to catch up to the car in front of me. And instead of downshifting or moving the RPMs at all, it seemed to ignore me altogether. So I let off and tried again and this time was greeted with some movement of the needle but WAY below what I expected to feel. After getting off the highway, the car felt like the transmission almost popped out of fear completely while stopping. There was a steady deceleration then a noticeable clunk while stopping then it stopped a whole lot quicker. After this I rolled down my window for the remainder of the drive to see if I could hear anything out of the ordinary and noticed the car sounding throatier and still very sluggish. As of right now I’m very confused how all of these things could be caused by any one item and how none of these could throw a code.

Any thoughts or suggestions would be appreciated. Thanks in advance

DISCUSSION (14)

JGrabowMSt > Firewrx234
03/21/2016 at 16:28

Tough to say. Have you tried thrashing it a little bit? The HEMIWagon has been acting up lately, and only just threw a code last night on my way home. It would hesitate to shift up to the redline like timing was being pulled at the last second. Threw a Cam Position Sensor which explains everything, but it happened a number of times before finally throwing a code.

I’m also pretty sure I blew out the passenger side cat in the process because I’m getting a slight rattle from it now....always something...

Party-vi > Firewrx234
03/21/2016 at 16:28

have you tried driving and shifting up and down through all gears? Another option would be to disconnect the battery for a while and see if that helps your issue. have you been able to replicate the issue since?

Firewrx234 > JGrabowMSt
03/21/2016 at 16:30

That bites, good luck with that and I'm gonna hook up my obd scanner and see if any of the numbers look weird

Firewrx234 > Party-vi
03/21/2016 at 16:32

I just parked before I made this post. And as far as gears go, it seems to be sluggish in all of them. I'm wondering if the transmission issue is just the car expecting more power under deceleration and there just wasn't the resistance it was expecting. Idk, I'm just talking now because it was such a strange sequence of events.

AMGtech - now with more recalls! > Firewrx234
03/21/2016 at 16:33

I would bet it did set a fault, just hasn’t set a light yet. It’s hard to guess without having experienced it. But the fuel pumps, either high or low, could cause what you’re describing. Except for perhaps the clunk, but that sounds on the type and location of the clunk, so let’s just worry about what we know because I’m pretty sure it’s all going to be related.

RallyWrench > Firewrx234
03/21/2016 at 16:40

Have you tried driving it since this episode? Does it clear up after cycling the key? I wouldn’t be at all surprised if you see the MIL on another drive attempt. It almost sounds like the transmission has entered limp mode. If it’s stuck in 3rd gear and you’re on it, the engine will be trying awfully hard to move the car at lower speeds. Several possible causes if this is the case, most commonly the gang plug for the transmission electronics at the right front corner of the trans, just at the back of the bellhousing. They often fill with ATF, which can send all kinds of mixed signals to the EGS (TCM).

Firewrx234 > RallyWrench
03/21/2016 at 16:47

I think I’m gonna hook up my obd scanner and see if anything popped up.

Firewrx234 > AMGtech - now with more recalls!
03/21/2016 at 16:48

I'm gonna be hooking up my obd scanner soon and see what came up. I'm curious to see if any of the numbers look off.

RallyWrench > Firewrx234
03/21/2016 at 16:53

If it’s a transmission code, the generic scanner will just show a MIL request from the transmission control, P0700 or 710 I think. All that means is that there are codes in the trans module.

AMGtech - now with more recalls! > RallyWrench
03/21/2016 at 16:54

This car has the 722.9 trans, which doesn’t have that leak issue you’re talking about like on the .6 trans. 99% he’s got a fuel pump issue, high or low.

AMGtech - now with more recalls! > Firewrx234
03/21/2016 at 16:55

Whatever you do, don’t clear anything out. And your scanner may not read all of the codes, FYI. So if there is nothing there don’t worry too much.

RallyWrench > AMGtech - now with more recalls!
03/21/2016 at 16:58

Derp, I forgot there was no W203 C250, thought that’s what he was in. Could still be a valve body with the 722.9, but in this case the fuel pump is more likely.

Firewrx234 > AMGtech - now with more recalls!
03/21/2016 at 17:32

Yeah most definitely won't clear it but intrigued to see what it shows

AMGtech - now with more recalls! > RallyWrench
03/21/2016 at 19:47

Yeah. I’ve done loads of high and low pressure pumps on these for CEL’s, lack of power, tough run, and extended crank situations.