2001 E320. power surge after worm up. Wont get out of its own way. - PeachParts Mercedes-Benz Forum

davidlee · #1 03-08-2015, 07:38 PM

This last Friday my girlfriend bought a Gorgeous white E320 with 115k that she has been staring at on a used car lot for some time about 7 months. they started out asking 8995, we picked it up for 6300 cash. and we took a short trip up Interstate 5 from Portland to Seattle. It drove like a dream. We drive around Seattle for an hour or so and it started to develop a miss. then a faint pulsating whurring sound coming from the rear of the cabin and the engine power started pulsating like stepping on the gas then letting all the way off then apply power then release then apply etc....etc...., so we pulled over to the side of the road. now mind you, she has wanted this car so bad, she sold her newer car still under factory that she had owned for nearly 8 years and took all the money and went and bought this. there's not much the lot is gonna do for me at the price i got it at. I buy and sell cars here and there, I know how it works. the car lot said it was a trade in not a car he personally bought at an auction. He said it was a good car no issues when traded in. I believe him, he always sells nice cars but not luxury cars. he would have ran it through the auction otherwise instead of selling under his good name. It looked out of place the whole time is was on the lot. This lot has been in business for nearly 40 years. that doesn't happen by selling the public junk.
So if i disconnect the batt. for a couple minutes and then hook it back up problem solved for a minute or so the the sound come again and the pulsating. we where able to reset it right before we entered the freeway to return home and I was able to get it up to cruising speed and we make it all the way home, this morning it was fine and now this afternoon its all came back to avenge its title.
sounds like the fuel pump but could it be the computer controlling it?
DUMBFOUNDED???????? any help please
THANK YOU
a buddy of mine laughed and called the problem LOT ROT he said it happens some times when cars sit around a lot to long with out driving it, but the battery kept a charge the whole time there.

Frank Reiner · #2 03-08-2015, 11:46 PM

"2001 E320. power surge after worm up."

WORM UP ? Cue the early bird!

davidlee · #3 03-09-2015, 02:01 AM

Your eye is keener than mine. I stand corrected, cheers.

Zulfiqar · #4 03-09-2015, 11:22 AM

any error codes?

your symptom also sounds like bad gas or a failing fuel filter - the fuel pressure regulator on this car is built into the fuel filter and does cause strange noises too when failing.

Can't Know · #5 03-09-2015, 12:19 PM

I would definitely plug in a code reader. If you didn't do a PPI, it's very possible the dealer pulled the MIL bulb.

What you are describing, symptom-wise, is that the engine is experience serious misfires and the ECU is shutting down one or more cylinders to prevent damage. That would explain both the power loss as well as the pulsating.

That said, with your additional symptom, I think you at the very least have to replace the fuel filter. When they become clogged they strain the pump and that whirring/whining is just how they sound. (Of course they also sound like that when they are failing.) The fuel filter is inexpensive and easy to replace (though if you don't have clic clamp pliers you'll need to cut off the factory hose clamps and replace them with conventional worm-gear type).

So, to summarize, I would scan the car for codes, and if they are just misfire codes (in the P0300-P0306 range) then I'd replace the fuel filter. Oh, the heck with it, I'd replace the fuel filter regardless.

If you have codes other than misfire codes post them and we'll lend advice. You can go to any autozone store (outside of CA) and they'll read codes for free, but I'd recommend buying a basic code reader, like the MS-309, about $20 at Amazon, it will read and clear your typical OBD-II codes (MB specific stuff you need much more, but that's true with any make anymore).

In the meanwhile, I would stop driving it at least until you get the filter replaced and the codes read.

Good luck.

Zulfiqar · #6 03-09-2015, 01:06 PM

misfires on this engine can mean a lot of different problems - I have run across a few

a - primary cat converters shot and broken - (choked exhaust)
b - bad spark plugs or ignition coils
c - bad fuel filter
d - bad MAF sensor
e - bad or clogged injectors

the ECU on this car is very smart and very closely reads the engine crankshaft position sensor for firing pulses (acceleration) - this is good and bad at the same time, the good is that it immediately shuts down the injector driver for a faulty cylinder to prevent raw fuel ignition in the cat converter which can kill it - but the engine still runs.

the bad is that more than 1 cylinder shut down will render the car as powerful as if its being towed by a lawn mower.

First things first - get a scan tool and read any codes - please do not disconnect the battery on this car as it then requires recalibration of the body modules like throttle pedal, windows, sunroof, radio etc.

davidlee · #7 03-30-2015, 11:49 AM

changed the fuel filter with no other check engine lights on other than the misfires while I was having the issue, the car ran great for three weeks until I took it on a 200 mile round trip yesterday and when I got at the farthest point away from home it did it again.
I was able to find an other filter locally and replaced it again.
this time it seems to be misfiring until I really throttle down on the fuel then everything seems to clear out and she runs out real good but only if my pedal is down hard

davidlee · #8 03-30-2015, 11:50 AM

oh yeah forgot to mention thank you to everyone for all your suggestions last time also it is making that pulsating whirring soundfrom the fuel pump when it starts acting up could the fuel pump be the issue or could it be because of the off brand new fuel filter regulator not getting the right message sent to it

Zulfiqar · #9 03-30-2015, 11:57 AM

Quote:

Originally Posted by davidlee

oh yeah forgot to mention thank you to everyone for all your suggestions last time also it is making that pulsating whirring soundfrom the fuel pump when it starts acting up could the fuel pump be the issue or could it be because of the off brand new fuel filter regulator not getting the right message sent to it

The fuel pressure regulator in this car is built into the fuel filter, A bad filter can cause the regulator to squeal or drone too.

Its a full mechanical part, I dont quite understand what message can be sent to it.

davidlee · #10 03-30-2015, 12:05 PM

2001 E320. power surge after worm up. Wont get out of its own way.-20150330_091120.jpg

davidlee · #11 03-30-2015, 12:10 PM

Quote:

Originally Posted by Zulfiqar

The fuel pressure regulator in this car is built into the fuel filter, A bad filter can cause the regulator to squeal or drone too.

Its a full mechanical part, I dont quite understand what message can be sent to it.

sorry let me clarify, you guys think that the fuel pressure regulator might be bad in the new fuel filter i just installed or are we looking at another issue?

Zulfiqar · #12 03-30-2015, 12:45 PM

Quote:

Originally Posted by davidlee

sorry let me clarify, you guys think that the fuel pressure regulator might be bad in the new fuel filter i just installed or are we looking at another issue?

It is quite commonly known that only two fuel filter brands work on this car, one is OE Mercedes Benz genuine part and the other is Bosch.

Other brands do strange things, like be noisy, jumpy fuel pressure etc. Which one did you buy?

davidlee · #13 03-30-2015, 01:30 PM

Quote:

Originally Posted by Zulfiqar

It is quite commonly known that only two fuel filter brands work on this car, one is OE Mercedes Benz genuine part and the other is Bosch.

Other brands do strange things, like be noisy, jumpy fuel pressure etc. Which one did you buy?

Well. the first time I changed it I used a factory Mercedes replacement. yesterday I was in a pinc, only one auto parts store in town. O'Reilly, they only had their house brand which also happens to be the only one in stock so I bought it I can't even remember what brand it was

davidlee · #14 03-30-2015, 02:00 PM

I talked to the auto parts store they are going to credit me back the money I spent on the filter and warranty it out I am going to Mercedes Benz today right after work to grab another factory replacement and I will get back to you guys on progress.

Can't Know · #15 03-30-2015, 02:01 PM

Quote:

Originally Posted by davidlee

Well. the first time I changed it I used a factory Mercedes replacement. yesterday I was in a pinc, only one auto parts store in town. O'Reilly, they only had their house brand which also happens to be the only one in stock so I bought it I can't even remember what brand it was

You've gone through two fuel filters, are you still getting the whining? If not then you can *probably* ignore fuel supply for now.

if you are still getting the whining, then I'd drain the fuel and pull the screen and see if it is clogged/fouled. You'll need a new O-ring, but the screen itself should be reusable. If the whining continues after that I would replace the pump.

If the whining is gone, then I'd start looking at all the intake seals and vacuum lines. Your pulse/misfire is now a higher rpms, right? That's when that stuff is super-critical because air demands are at their peak, and that's when a minor leak can become a major problem. So I'd replace all vacuum lines/hoses (including the breather hoses) as well as the intake seal at the TB. Trace the lines back as well, sometimes you can find a T that is cracked, etc.

That's pretty minimal expense and just a time layout.

Then reset and see where you are.

Good luck.