2005 e320cdi-- loss of acceleration with huge increase in MPG?? - PeachParts Mercedes-Benz Forum

wallbenz · #1 01-30-2021, 01:49 PM

Any ideas? 3 weeks ago CEL... Indy scanned it and said it was issue with GP controller.

went on vacation-- I still have the CEL-- but noticed 2 things

I lost the awesome acceleration in all gears on this car... BUT- on positive side
computer says I am getting around 40mpg + on my rural local drives.

Couple times- I started and had the "Normal acceleration" - but MPG went back to around 32 mpg on my 20 Minute drive.

Any thoughts? I can still hear the turbo whine/whistle - in either case.

shertex · #2 01-30-2021, 05:53 PM

I’m having difficulty imagining what the connection could be between the glow controller and the lack of acceleration.

dieselbenz1 · #3 01-30-2021, 06:52 PM

If you want the crappy diesel milage have the codes read again sounds like egr. But if you like the better milage leave it alone.

250 Coupe · #4 01-31-2021, 01:27 PM

This is just a random thought but I do wonder how it would behave if the torque converter was locked at all times. You would lose torque conversion which might make it drive as if it’s in too high a gear and the reduction in slippage might improve mileage. Or it’s in a low power limp home mode although you usually know right away when that happens as it’s a real pig to drive.

Michael

Usaguy · #5 01-31-2021, 07:46 PM

Quote:

Originally Posted by 250 Coupe

This is just a random thought but I do wonder how it would behave if the torque converter was locked at all times...l

You would stall as soon as you would put it in gear

Or if you somehow managed to pull away then you would stall when coming to a stop

250 Coupe · #6 01-31-2021, 08:23 PM

Oh yea, kinda forgot about needed to slip while in gear and stopped.

It’s safe to ignore me 😉

Michael

wallbenz · #7 01-31-2021, 10:01 PM

Quote:

Originally Posted by 250 Coupe

This is just a random thought but I do wonder how it would behave if the torque converter was locked at all times. You would lose torque conversion which might make it drive as if it’s in too high a gear and the reduction in slippage might improve mileage. Or it’s in a low power limp home mode although you usually know right away when that happens as it’s a real pig to drive.

Michael

It is NOT in the limp mode... had that several times when I first bought the car.
Had the EGR deleted and swirl flaps - left in open.

Right before the CEL-- I replaced BOTH batteries- which is when the CEL came on- immediately after i replaced batteries.

The Car did NOT have this random Lower power/acceleration and ++ mpg's right away... about 2-3 weeks after CEL (which My Indy said was GP Module) and battery change- this condition started.

As a previous poster suggested-- might just leave it alone- and enjoy the MPG. Car still moves ok- but no longer flies.

Just wondering if anyone has ideas on what is up??