WolfStagen

Has this ever happened to you? Is it because the car's computer is learning and adapting to my driving style? I have had my car for a year now, brand new from the factory, 0 problems whatsoever, 13k on the speedometer.

I remember that when I used to push the pedal to the floor on 2nd gear, the car would aggressively pull forward, and I would be glued to the seat. But while driving this week, as I floored the pedal on 2nd gear, the RPMs rose but the car was very slow and sluggish, no aggressive pull whatsoever, as if something is wrong.

Looking at the gauges, I tried a couple of tests, horsepower goes all the way up to 600, and torque is around 600 as well. The boost gauge is working. I tested the launch control and did get 3.4 seconds, same as it did a couple of months ago.

Is the car adapting to my driving style perhaps? I drive a lot more on 3rd gear lately and it seems to be okay on that gear, but it really feels like something is wrong on second gear as I push it. It feels very sluggish and slow, quite strange pushing the pedal all the way down on 2nd gear and the car is barely moving forward compared to before where it would almost give me a heart attack.

Any insight would be greatly appreciated, thanks!

E634Me

What mode? Comfort, Sport+? Is the car fully warmed up? Assumed so, but just asking in case.

Accidentally did a launch at a stoplight the other day in Comfort mode. My Individual mode is Comfort + Exhaust valves open. Normally by that time in my drive I've flicked it to Sport+.

First thing I noticed is that the car seemed to rev a bit anemically, not the full 3500 or whatever RPM it usually goes to. On launch it took off fairly well, but didn't get any of the normal pavement shredding action where the tires are really being worked hard. It was the first race start I'd done in a while but I thought that seems less dramatic than I remembered.

Once I realized what had happened, had to go find another spot to give it a go in proper Sport+ mode and verify all was as it should be and it was. Just a bit over 12, 000 miles on the car now.

Car still seems to pull normally in 2nd for me. We have a pretty rough surface in our parking garage at work and in 2nd the car does briefly light up the tires if I romp on it as I'm transiting between floors.

WolfStagen

Had it both in Sport+ and Race mode at different times, car fully warmed up at that point. It's really strange, the only explanation I can think of is that maybe the car is adapting to how I drive and so say I have been pushing it hard on 3rd gear and so it would adapt to give maximum acceleration and torque at that gear.

Perhaps, if I could experiment with "re-teaching" the computer, and push it often on 2nd gear and see if it re-adapts.

E634Me

Checked mileage last night when I filled up on the way home. 12,850. So in another week or two I'll pass 13 k. Will see if I notice the same issue.

Doubt it though, as I'd suspect that Race mode would give you full beans on demand without regard to any adaptation for the more genteel driving modes.

Maybe you've adapted ?;-)

WolfStagen

That was the first thought in my mind, "Maybe I got used to the crazy acceleration?"

The good news is that I went out again last night to give it another go and it went all out this time, I was glued to the seat. So not sure exactly what's happening, I will keep trying and see if I can find any patterns.

ronin amg

Patterns you say...

PeterUbers

Some 2018 guys were losing boost ... it was easily fixed as it was an electrical problem, or an exhaust flap issue

https://mbworld.org/forums/w213-amg/...ost-power.html

https://mbworld.org/forums/c63-c63s-...-anyone-2.html

https://mbworld.org/forums/w213-amg/...w-what-do.html

amgliturbo

Was it really hot and humid out when you experienced the problem--heat and humidity definitely have a big impact on turbo performance--I loose over a full .1 of a second (sometimes more) 0-60 in hot and humid weather. Also I don't know how accurate the boost gauge is in these cars--I am guessing not very. It might have performed fine on your night test due to lower temp at night..

WolfStagen

It was! But it felt more like I am losing 1 entire second rather than 0.1 seconds. It's as if I need to be at a certain RPM in second gear before depressing the pedal fully to the floor for maximum acceleration to kick in. Very weird.

amgliturbo

I do not know if this happens in these cars but in other vehicles I have owned every now and again when it is very hot and humid you can get some vapor lock in the fuel line that can result in the engine not getting full fuel flow--sometimes not noticeable if not accelerating hard but once the engine calls for more fuel it doesn't get enough and the car hesitates or feels real sluggish. Also back in March I filled my tank up at a gas station that was not the one I usually go to--It was a Sunoco station but was in a poor part of the town I was in and the station looked pretty shabby. Right after that fill-up I thought I noticed that the car wasn't pulling as hard as normal--checked with a few 0-60 runs with Dragy and sure enough the car was doing 3.5-3.65. The week prior I was pulling 3.1-3.15. Finished the tank and filled up at my usual station and was back to normal with 0-60 times back down below 3.2. I honestly don't think your issue has anything to do with the car learning/adapting to your driving style--usually systems like that don't impact full on/ mash the pedal to the floor performance but I could be wrong.

Slugsy

I get this quite a lot, in comfort and especially moving away from roundabouts and lights.

i was thinking of getting it in to be checked, it’s quite annoying. If I it’s not past +2,000 revs, it is definitely a bit sluggish

WolfStagen

I am starting to get a better idea of what's going on. I was watching the turbo boost gauge and I floored the pedal, the turbo would not move past the half waypoint. This would happen on both 2nd and 3rd gear. Then I would come to a stop and it would shift back to first gear, I would give it another go and it would start going all the way and the car feels fast again.

At first, I started thinking that there is definitely something wrong with the car, but then it would start working again. So weird...

How do dealerships usually test for those kinds of issues? Do they have a dyno? I really hope they don't give the car to some kid mechanic who takes it for a ride out at the back and floors it...

MuffinFlavored

is it knocking from costco gas?

WolfStagen

Unless the gas station mixed up their fuel, it's running on 94!

amgliturbo

Did you ever figure out what was going on with your car? Have you filled up your tank with different gas since this happened and/or what has the dealer said is causing the problem?

WolfStagen

Unforutnately no. It does this only 5% of the time. Most of the time it's fine so I can't tell if its how the car is designed or if there is something wrong.

It's more likely to happen if I am in a country side road and have been pushing the car a little harder. It's as if the turbos get too hot or something and only get 50% boost or less as the maximum.

When I stop at a light and push it again from 0, it has a 80 20 chance of working properly or doing this.

So for now I decided unless it doesn't work most of the time I will just let it be and will mention it to the dealer when I bring the car for winter tire installation in about 2-3 months.

It would be interesting to know if anybody ever experienced something similar with their car.

amgliturbo

It seems to me like there is something going on that isn't right--I will notice a momentary lag when in comfort or sport when I mash the pedal but it is simply the car shifting down and the turbos spooling up. In S+ and RM there is an almost imperceptible lag but nothing that causes me any worry. I would bring it into the dealer sooner rather than later just to be safe. Also when I am pushing my car it displays less lag and runs sharper since everything is warmed up.

Ralcbah

When the exhaust system valves (and eventually actuators) started to fail on my car, it wouldn't hold boost after 4k rpms. For the first week or so it was intermittent. The car is designed to do that when the muffler/hpipe valves aren't functioning. Eventually the valve/actuators failed and then the car did not make boost after 4k again....until valves/actuators were replaced. Might be that your stuff is starting to fail and your starting to see this intermittently. Longshot, but worth checking out.

WolfStagen

Hmmm, okay, that doesn't sound good. Was the replacement covered under warranty? And how long did it take to get it fixed? I think I'll take it to get checked after all then...

Ralcbah

Yes, it will be a warranty deal. May as well have them take a look.

KJ

Perhaps the AMG exhaust valves are sticking due to corrosion from to Canadian winters.

WolfStagen

After only 1 winter? I am going to make an appointment with the dealer to take a look. I wonder how they will go about testing it.

WolfStagen

Ralcbah, I just re-read all your previous posts about the problem you had. Took the car out for a drive again and I think I am having the exact same issue you did. Power does cut off after 4000rpm, not only the boost but the horsepower gets stuck at around 300HP. I think it's getting worse too, It does it much more often now.

Sucks, up to this point I literally had 0 problems and thought how awesome Mercedes engineering is.

I am afraid my dealer would not be able to diagnose it either... Did you basically just replace the valves/actuators or the entire performance exhaust? I want to give them a starting point once they start looking into it so that they don't take the whole car apart.

Ralcbah

Well the car itself is pretty amazing...these valves, however, are pretty crap. But I hear ya. They'll change the valves/actuators only, as required. Remainder of exhaust system will be fine. Def tell them you are suspecting this as a potential.

Ralcbah

...missed a question. I changed to the awe exhaust, but more for sound reasons. If this is your issue, it's def fixable.