BMW M5 Forum and M6 Forums banner

1 - 20 of 33 Posts

·
Registered
Joined
·
1,548 Posts
Discussion Starter · #1 ·
Whats up guys..

I'm hoping someone here has had some experience with this..

Now it is my understanding that sport mode crisps throttle response and helps the car move along quite a bit better, and in most cases, it does do..
However, occasionally when I push the sport button and want to get on it I feel that it is lacking and the car was faster before I had push the button.. it sometimes feels like the car bogs down more often even..
Also at times there is what sounds like a gurgle coming from the engine in the lower rpms.. mainly noticeable in 2nd at 1k-2k rpms , 3rd at 1.5k to about 3k rpms.. hard to describe when it makes this struggling noise but it also will do it when I press the gas all the way in 5th at 80mph but if I were to press the gas about halfway the car accelerates better..

Sorry for the confusing situation that I have laid out above.. lol

List of items that are new and on the car include: new mafs, spark plugs, both precat 02 sensors, air filters, cabin airfilters, Intake cam position sensor Bank 1.

No codes and car still pulls hard *most* of the time

Thanks gurus :prof:
 

·
Registered
Joined
·
3,085 Posts
Well it sounds like you are aware of this but just to be clear, there is zero power gain from pushing that sport button. All it does is reduce power steering assistance and tighten throttle response. The car might feel faster but it really isn't, you just don't have to put your foot down as far.

Regarding it feeling sluggish in sport mode?? Not sure....I don't fully understand your diagnosis either. The only thing I can think of is a possible exhaust cam position sensor going out, but if there are no codes present that is unlikely.
 

·
Registered
Joined
·
1,453 Posts
Heat soak comes to mind
 

·
Registered
Joined
·
1,548 Posts
Discussion Starter · #4 ·
Heat soak comes to mind
Heat soak?

And yea I'm aware that it isn't "faster" but more responsive..
Instead of just being more responsive it feels like Im actually losing some pull.. Weird I know..

And the engine bogs down in a wider low rpm range..
When not in sport it does it less but it still is present..

Maybe I should be in lower gears then? But then again.. 2nd at 2000 rpm should start a strong pull to redline..
I'm going to be paying more attention to exactly when this sound/loss happens..
 

·
Registered
Joined
·
1,195 Posts
I actually enjoy the car more with sport off, it feels easier to modulate the throttle, yields smoother take offs, but the power is all there just more pedal to get it. The tighter steering is really sort of silly for how I drive the car...I don't drift, only counter steer if i am screwing up or hit something slippery...DSC on the other hand makes the car drivable; the loss of power suddenly on on-ramps or when trying to get across a busy intersection is really un nerving...Unless its really snotty out, I ALWAYS turn DSC off...
 

·
Registered
Joined
·
1,548 Posts
Discussion Starter · #6 ·
The sound is similar to if u were to put ur car in sixth at about 55mph and try to acclerate...
Sounds like "brrrgrggrggggrrrr" bogging as some may call it..
 

·
Registered
Joined
·
1,548 Posts
Discussion Starter · #7 ·
The sound is similar to if u were to put ur car in sixth at about 55mph and try to acclerate...
Sounds like "brrrgrggrggggrrrr" bogging as some may call it..
 

·
Registered
Joined
·
205 Posts
The MAF and O2 sensors are not fast enough to keep up
with the more sudden changes in airflow from the remapped
throttle. Doesn't matter if those parts are new or not.
What happens is that the car more frequently runs lean briefly on
throttle tip-in and sets off the knock sensors. When this happens enough,
the DME pulls back on baseline timing. Your car gets slower.

The acceleration-enrichment mode that the DME runs (like all makes and models run)
probably isn't enough in sport mode. And even new O2s take a half second minimum to respond
to wide changes in engine load.

And we live in a state with barely adequate octane (91), further exacerbating
the situation.

Best to leave the sport mode off around town, and use it for the
tighter steering on the freeway.
 

·
Registered
Joined
·
1,548 Posts
Discussion Starter · #10 ·
Can you duplicate the symptom in normal mode buy being harder on the gas?
Yea I can.. being hard on the gas is what causes it..

And to fulltone74..
Soo.. There's no solution for that? Just the way we can expect some of our cars to be? Really?
 

·
Registered
Joined
·
4,415 Posts
Sounds like MAF or fuel delivery. Since you have a new MAF, check the fuel pump and consider replacing the fuel filter.
 

·
Registered
Joined
·
3,968 Posts
Whats up guys..

I'm hoping someone here has had some experience with this..

Now it is my understanding that sport mode crisps throttle response and helps the car move along quite a bit better, and in most cases, it does do..
However, occasionally when I push the sport button and want to get on it I feel that it is lacking and the car was faster before I had push the button.. it sometimes feels like the car bogs down more often even..
Also at times there is what sounds like a gurgle coming from the engine in the lower rpms.. mainly noticeable in 2nd at 1k-2k rpms , 3rd at 1.5k to about 3k rpms.. hard to describe when it makes this struggling noise but it also will do it when I press the gas all the way in 5th at 80mph but if I were to press the gas about halfway the car accelerates better..

Sorry for the confusing situation that I have laid out above.. lol

List of items that are new and on the car include: new mafs, spark plugs, both precat 02 sensors, air filters, cabin airfilters, Intake cam position sensor Bank 1.

No codes and car still pulls hard *most* of the time

Thanks gurus :prof:
check for stored codes, sounds like bad exahust cps.
 

·
Registered
Joined
·
12,961 Posts
The MAF and O2 sensors are not fast enough to keep up
with the more sudden changes in airflow from the remapped
throttle. Doesn't matter if those parts are new or not.
What happens is that the car more frequently runs lean briefly on
throttle tip-in and sets off the knock sensors. When this happens enough,
the DME pulls back on baseline timing. Your car gets slower.

The acceleration-enrichment mode that the DME runs (like all makes and models run)
probably isn't enough in sport mode. And even new O2s take a half second minimum to respond
to wide changes in engine load.

And we live in a state with barely adequate octane (91), further exacerbating
the situation.

Best to leave the sport mode off around town, and use it for the
tighter steering on the freeway
.
I don't think so. Never had that problem with Dinan software, Powerchip software, headers or ESS.

I suspect there is a problem with the OP's car. Something not significant, but there. Checking for stored codes is very good idea, although a marginal CPS may not throw a code. But I don't know why a bad CPS would only show up under sport mode.

Doesn't sport mode adjust the TPS settings? Or is it the potentiometer? I would look at things that we know are changed when the sport button is pressed.

Regards,
Jerry
 

·
Registered
Joined
·
205 Posts
Yea I can.. being hard on the gas is what causes it..

And to fulltone74..
Soo.. There's no solution for that? Just the way we can expect some of our cars to be? Really?
I'd say so. The octane and fuel just isn't good enough. Not for 11:1 compression. Especially throwing ethanol
into it. Octane is cut down from the gasoline and boosted up with the ethanol.
But ethanol doesn't stay in constant percentage in the tank (car or gas station). As you can guess, it can play havoc on the octane your engine is getting. Not as serious a problem in states that have 93 octane. But we are at a disadvantage with 91.






Let's just say i've owned four cars in California. Two nissans and two bmw.
Despite my best maintenance efforts and spending large amounts of money, none of them have run in top condition consistently. Performance changes noticeably from one tank to the next, despite using top tier 91 octane and occasional cleaners.

My next car will be something that takes 87 - and I'll run 89 or 91 in it.
 

·
Registered
Joined
·
12,961 Posts
I'd say so. The octane and fuel just isn't good enough. Not for 11:1 compression. Especially throwing ethanol
into it. Octane is cut down from the gasoline and boosted up with the ethanol.
But ethanol doesn't stay in constant percentage in the tank (car or gas station). As you can guess, it can play havoc on the octane your engine is getting. Not as serious a problem in states that have 93 octane. But we are at a disadvantage with 91.






Let's just say i've owned four cars in California. Two nissans and two bmw.
Despite my best maintenance efforts and spending large amounts of money, none of them have run in top condition consistently. Performance changes noticeably from one tank to the next, despite using top tier 91 octane and occasional cleaners.

My next car will be something that takes 87 - and I'll run 89 or 91 in it.
If octane is the issue, then it seems we can test for that. Either get some unleaded race gas (typically 100 octane) and do a mixture to get up to 94 or 95 octane.

Or get some good octane booster (google Torco) and add that.

I would say give the DME about 30-50 miles to adapt and see if the issue improves.

Regards,
Jerry
 

·
Registered
Joined
·
1,548 Posts
Discussion Starter · #16 ·
Alright thanks guys.. I'm gonna see about testing the octane with the octane booster.. but in the meantime..
Went on a drive and noticed something that we can add to the case.. Sport mode on its way more pronounced but..
4th gear at 80mph.. Pressing the gas about a quarter of the way down and the car accelerates at lets say a rate of X..
Pressing the gas half way down the car is still accelerating at a rate if X BUT makes the brrgrr hesitation noise in the background possibly even slowing the rate of acceleration a tad bit..

Did the thermostat test and I think I can rule that one out.. On the freeway in 6th gear, the temp was 78 at the lowest.. mostly remained at 79 but if I got on it and dropped the gears would go up to about 80-83 or so.. Which if I've understood correctly from the other threads this is normal..

Here are a couple other symptoms I've noticed after my drive right now that may or may not be related..

1. When the car is started cold, i.e all the lights on the RPM guage are lit and temp needle in the blue, the car will shake/rumble for a couple minutes and begins to smooth out later when the cars been driven a bit and gets warmer.. maybe this is normal..
2. With the car warm.. sport mode on or off and idling in neutral.. a quick stab of the gas to rev the engine will sound like "CLICK" then a small hesitation THEN it will rev up and not hesitate.. until I let the engine all the way back to idle at which point the same thing occurs. So *Click vrrvrr* THEN revs will climb.
4. Engine is starting to sound strained again when I am being hard on her.. But still no codes

Hmm.. I think 3 new cps are in my future? I believe I DID hear a deep sound from the exhaust that sounded like the exhausts were blocked then unblocked real quick.. or maybe this is my mind/car playing tricks on me because I'm looking for anything I can... :Thumbdown:
 

·
Registered
Joined
·
2,450 Posts
  • Like
Reactions: JCM55555

·
Registered
Joined
·
10,326 Posts
That makes perfect sense especially with the idle being off. Got a feeling there maybe a few maintenance issues combined.
 
1 - 20 of 33 Posts
Top