Engine Issue???

[THE TECH]

Did some searching but not sure what terms to really use to find anything in regards to this. I just noticed that the car seems to "hesitate" in the 2500-3500ish rpm range. I don't physically see the tach changing during these instances. For example, I am on the freeway holding in this rpm range and the car will bog then come back to normal. It will do this often. No CELs or any other lights. I assume this is not normal.

[E30_80Y]

I think I noticed the same. Anybody have inputs on this?

[BPMSport]

Stock exhaust?

Info on mods would be helpful.

[immiketoo]

Does not sound normal at all. Could be a DCT issue?

[M3PO]

That doesn't sound normal to me.

[brava09]

Same here, but only in 3rd gear. Stopped worrying about it though, since it is doing this from the beginning.

[Mike van D]

No issue like that here. Agree, not normal. Happens all the time or just started? If not all the time I would suspect that you possibly got a small slug of or some entrained water in your last fill-up.

[BMRLVR]

Originally Posted by THE TECH

Did some searching but not sure what terms to really use to find anything in regards to this. I just noticed that the car seems to "hesitate" in the 2500-3500ish rpm range. I don't physically see the tach changing during these instances. For example, I am on the freeway holding in this rpm range and the car will bog then come back to normal. It will do this often. No CELs or any other lights. I assume this is not normal.

What you are noticing is most likely the torque dip that everyone talks about. I notice it in my car too and the Akrapovic Evo made it even more noticeable. For me it really only bothers me in 6th gear travelling about 70-80 KM/h (45-50 MPH) then roll open the throttle, the car hesitates a little until revs build to about 3200RPM and then all is ok.

A quick downshift will eliminate this for you, I don't think there is any issue with your car, that is normal for the S65, especially if you have a HFC's or a cat-less mid-pipe!

[THE TECH]

Well I notice it at cruising speeds with a constant throttle. Feels kinda like the brakes grab for a moment then let go then grab again, then let go. So it could be engine or something else for all I know. As far as mods go, I have MS Stage2 intake, Akra Evo, Evolve tune, MS pulleys.

I don't think it's the torque dip since it happens when the engine is running at a constant rate and not during acceleration.

[spdy330]

I have not experienced anything like this.

[THE TECH]

Originally Posted by mamadotie

Feels kinda like the brakes grab for a moment then let go then grab again, then let go. So it could be engine or something else for all I know.

That's just to explain how it feels. I in now way know where the issue stems.

[Jbook]

Definitely does not sound normal

[GIdriver]

Mine doesn't do that, or at least I haven't noticed. Will pay more attention from now on. Please keep us informed. Sorry could not be of any more help.

[THE TECH]

I'll keep driving til I can figure it out. Could be engine, brakes, trans...

[BPMSport]

Originally Posted by THE TECH

I'll keep driving til I can figure it out. Could be engine, brakes, trans...

You should swing by and give me a ride so I can feel what it does, at the same time while data logging the car to see what's happening behind the scenes.

The Akra dip is between 1900 and 2500 ish - the car should feel normal from 2500 to 3000. I have never had such an issue. Definitely not normal.

We can try flashing to a newer ECU revision to see if that fixes the issue - not sure what software level you are on now, but I can check.

[THE TECH]

Originally Posted by Mike Benvo

You should swing by and give me a ride so I can feel what it does, at the same time while data logging the car to see what's happening behind the scenes.

The Akra dip is between 1900 and 2500 ish - the car should feel normal from 2500 to 3000. I have never had such an issue. Definitely not normal.

We can try flashing to a newer ECU revision to see if that fixes the issue - not sure what software level you are on now, but I can check.

Sounds good. I'll definitely have to make some time to come by.

[SchnellM3]

Originally Posted by GIdriver

Mine doesn't do that, or at least I haven't noticed. Will pay more attention from now on. Please keep us informed. Sorry could not be of any more help.

+1

From reading the OP I thought it could be a DCT issue but any hesitation with that is usually coming from idle to just under 2k then smooths out.

Since your a 6 speed owner that thought is null lol

I'd take Mike up on his offer and keep us posted, Good Luck

[THE TECH]

I still need to get by to see Mike regarding this and some other things, but I might have possibly narrowed it to a DSC issue. After doing some research here, I came across some info about checking if the issue occurs with and without the DSC on. I made my normal drive to work today and drove with the DSC off to see if the issue would keep happening. It seemed that with the DSC off, the issue wouldn't happen. As soon as I turned the DSC back on, it would start happening again. I have yet to get any sort of CEL in regards to any of this. I will check the situation again on my drive home to see if I can confirm that the same issues are in place. To be sure, I still will have Mike take a look at things and see if he can see any irregularities. This car has had more quirky issues than any other car I've ever owned...and it's only 4 months old.

[M3PO]

...and you didn't crash with DSC off?

[stefan]

Well that's kind of a relief. Makes me think the fix for this might simply be a software reflash or sensor change.

[K-M3]

Originally Posted by THE TECH

I still need to get by to see Mike regarding this and some other things, but I might have possibly narrowed it to a DSC issue. After doing some research here, I came across some info about checking if the issue occurs with and without the DSC on. I made my normal drive to work today and drove with the DSC off to see if the issue would keep happening. It seemed that with the DSC off, the issue wouldn't happen. As soon as I turned the DSC back on, it would start happening again. I have yet to get any sort of CEL in regards to any of this. I will check the situation again on my drive home to see if I can confirm that the same issues are in place. To be sure, I still will have Mike take a look at things and see if he can see any irregularities. This car has had more quirky issues than any other car I've ever owned...and it's only 4 months old.

hmmmm.... i was gonna say dsc, but, you said it first. mine's being doing it very rarely, in the rpm range that you talk about, but never while cruising. typicaly, when it has done it, it has done it when gassing it up out of a corner when it gets in that rpm range. its "jerky" is the best that I can describe it......i thought it could either be the traction control (DSC) kicking in and cutting power off, OR, it could be lower octane gas. never did it on my trip back with 93 octane in it, but started doing it as I get only 91 octane max where I am. engine diagnostics (at the dealer) all came back normal. it does it very rarely, so I am just going to watch it for now.

BTW, mine is bone stock......no mods whatsoever.....

[THE TECH]

Originally Posted by M3PO

...and you didn't crash with DSC off?

Yeah, I barely made it alive.

Originally Posted by stefan

Well that's kind of a relief. Makes me think the fix for this might simply be a software reflash or sensor change.

This is what I'm hoping. As soon as Evolve sends me an Akra delete file only, I am going to take out their tune to verify that it isn't causing the issue.

Originally Posted by K-M3

hmmmm.... i was gonna say dsc, but, you said it first. mine's being doing it very rarely, in the rpm range that you talk about, but never while cruising. typicaly, when it has done it, it has done it when gassing it up out of a corner when it gets in that rpm range. its "jerky" is the best that I can describe it......i thought it could either be the traction control (DSC) kicking in and cutting power off, OR, it could be lower octane gas. never did it on my trip back with 93 octane in it, but started doing it as I get only 91 octane max where I am. engine diagnostics (at the dealer) all came back normal. it does it very rarely, so I am just going to watch it for now.

BTW, mine is bone stock......no mods whatsoever.....

I have only been able to use 91 here in CA so not sure if that could be it as well especially if the tune is on the edge in some places.