Loss of power/rough idle
#1
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Takes the bus.
Loss of power/rough idle
Been like this for a little over a month in the w211
Drives like its capped @ 300hp with no ballsy torque either. Slight rumble here and there while idling. At start up, it sustains 1300rpm for around 30seconds before coming back down to normal idle rpm.
Any ideas? I need to know if this may or may not be serious in order to share with you guys the rest of the story.
Regardless, it is being checked out at the dealer Thursday, what should I look forward to hearing?
Thanks in advance
Drives like its capped @ 300hp with no ballsy torque either. Slight rumble here and there while idling. At start up, it sustains 1300rpm for around 30seconds before coming back down to normal idle rpm.
Any ideas? I need to know if this may or may not be serious in order to share with you guys the rest of the story.
Regardless, it is being checked out at the dealer Thursday, what should I look forward to hearing?
Thanks in advance
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Takes the bus.
No TB is not modded. How shall I check engine temps, just from the cluster? Lights are not dimming but windows do seem slower to going back up than before.
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Takes the bus.
Would a dead ICpump cause no power from the get-go though? Like lets say I give it some pedal a minute after start up and it just doesn't go like it should.
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Takes the bus.
Could the engine reach the temp of cutting the blower off within 30 secs of starting? because I just tried it out, gave it a lil pedal, not much output. and the engine was cold prior.
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Takes the bus.
Hopefully diagnosis is something minor like you had.
Dropping it off tomorrow morning.
#15
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Good luck! I am leaning away from the O2 being bad now since the check engine lights went away, unless there is a poor connection it might be a throttle position sensor issue a vacuum leak or a mass air flow sensor problem. Was anything done to the car before this issue arose ?
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Takes the bus.
Update: It has been at the dealer since yesterday morning. My SA and the service manager told me it will have to be here till Monday or Tuesday to check everything out... I'm not sure whats going on other than that.
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Good luck! I am leaning away from the O2 being bad now since the check engine lights went away, unless there is a poor connection it might be a throttle position sensor issue a vacuum leak or a mass air flow sensor problem. Was anything done to the car before this issue arose ?
Had a speed shop that I know put in new engine/tranny mounts, valve cover gaskets and air filter in the last week of January.
2 days later its ready.
I hop in turn it over, car is smooth as possible, with no more floor vibrations ( the mounts fixed that)
so I put it in gear and leave their shop. About 5-6 minutes later, at a light, i smell a faint stench of oil, and think its the car in front of me. (my windows are down). 1-2 minutes after that, stopped at a crosswalk, i see a small mist of smoke coming out from both sides of the hood, near the wipers. I immediately turn the car off.
I call my mechanic who did the work, he said its just oil that is still on the exhaust manifold that probably got on there when the valve covers were removed to add the new gaskets...he said dont worry about it the smell will go away in 1 or 2 days. So i turn the car back on and start driving it home.
5 minutes later the smoke is not getting any less. I'm panicking at this point and before i know it, i hear cars honking at me from all other lanes. I look in my rear view mirror and all i see is a trail of white/blue/gray smoke trailing behind me (im going about 40-45).
After looking in the rear view i notice my check engine has turned on, and a prompt popped on the engine cluster that I couldnt read in time. Something was displayed though. I turn off on a crosstreet and cruise for about 10 minutes back to the shop.
Before arriving, the smoke has subsided a little, but theres still smoke and mists of steam from under the hood, when i drive it around back, turn it off and open the hood with everybody around to see what the hell just happened.
My mechanic grabs a flashlight and looks over and under one of the valve covers on the left engine bank. Hes like Oh, ok i see what happened. There was alot of oil on that side of the engine bay..
He then explained to me that that side valve gasket was pinched inward on on part of the gasket, as it is supposed to sit in a groove, but that gasket was not properly seated.
He then tells me laughingly, "good thing you turned right around and brought it back now, if you drove it tomorrow, we would be buying you a new engine"
I'm quite irritated that this occurred but I hold all my frustration in. (many people tell me im too nice for my own good)
so he says they'll reseat the gasket and add "around 2 quarts of the oil that leaked out"
and that it will be ready tmrw morning.
The next day, its "ready". I get in and drive it (check engine still on, they said its pulling up vacuum leak codes, P505 or something) and that they'll take care of it later and its ok to drive it now. The car was very low on gas, so i drive it to the nearest station and fill up and bring it back to them.
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Takes the bus.
After bringing it back, they start working on trying to solve the problem in their bay. Around two days later, they say its ready. I go get it, start driving, and 5min later then check engine light flips on again.![bs](https://mbworld.org/forums/images/smilies/bs.gif)
Theres alot more to this story, but it would take me too long to type it all out. Lets just say they took it back in, Alex the mechanic took it to his MB buddy to do some smoke tests to find out where the leak is. Supposedly there was a leak where the plenum connects to the case and he resealed it. After that there was still the check engine light....
Then he takes it days later back to his MB buddy, where he was there with my car for over 5 hours.....and by the time hes back, theres 90 more miles on the car...... this time, the CEL is not on anymore...but the problem is still there....
Whats the problem that I'm facing you guys may be asking??
The following is the problem:
Ever since the valve leaked out the oil/coolant/whatever, the car has not driven near as well as it did before it happened.
Theres a rough idle, terrible performance, takes forever to get up to speed and there is a mist of blue smoke out of the pipes at times.....
Their excuse has been "its the spark plugs, you need new ones and it will be fine, no more rough idle, and it will perform like it did beforehand"
I gave them the benefit of the doubt for weeks now, since the problem was supposedly "fixed" about 3-4 weeks ago.
I decided I can't be the nice guy anymore about this and have to get to the bottom of the situation, which is why its at the dealer, where I have explained the situation in detail to my SA.
![bs](https://mbworld.org/forums/images/smilies/bs.gif)
Theres alot more to this story, but it would take me too long to type it all out. Lets just say they took it back in, Alex the mechanic took it to his MB buddy to do some smoke tests to find out where the leak is. Supposedly there was a leak where the plenum connects to the case and he resealed it. After that there was still the check engine light....
Then he takes it days later back to his MB buddy, where he was there with my car for over 5 hours.....and by the time hes back, theres 90 more miles on the car...... this time, the CEL is not on anymore...but the problem is still there....
Whats the problem that I'm facing you guys may be asking??
The following is the problem:
Ever since the valve leaked out the oil/coolant/whatever, the car has not driven near as well as it did before it happened.
Theres a rough idle, terrible performance, takes forever to get up to speed and there is a mist of blue smoke out of the pipes at times.....
Their excuse has been "its the spark plugs, you need new ones and it will be fine, no more rough idle, and it will perform like it did beforehand"
I gave them the benefit of the doubt for weeks now, since the problem was supposedly "fixed" about 3-4 weeks ago.
I decided I can't be the nice guy anymore about this and have to get to the bottom of the situation, which is why its at the dealer, where I have explained the situation in detail to my SA.
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E55
I just installed new valve covers and valve cover gaskets and there is a vent tube or something that can be easily knocked loose during the drivers side valve cover removal/install. It is a metal line that runs along side of the DS valvecover and then loops back under the throttle body and ultimately plugs into the lower plenum. I've heard those cause havoc if they get pulled out. You can check to see if this is in place with a mirror and a small flashlight when the plastic from your air filters to the throttle body is removed. That might be the source of your vacum leak. As for the smoke still coming out of your exhaust, no idea on that one. The mechanic should have changed your plugs with the VC's off. They are so much easier that way. Another reason for the car running rough is the wires might not be in the correct order between the coil packs and the actual plugs. Lastly, make sure the wires are connected firmly to the plug and coil pack. You will hear a click when they are truly connected.
Best of luck.
Todd
Best of luck.
Todd
#21
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Hope they figure it out but like todd edge also mentioned they could have knocked off the breather hose on the driver side which can cause ****ty performance and a rough idle. Let me know if they get it figured out and good luck.
#24
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Thats the vacuum hose should fix your issues, if there is a vacuum leak past the mass air flow sensor which is what this is it would trip out your ecu saying too much air is getting in thus dumping more fuel. Hopefully this is the only hose cracked