[AudiA4]

I posted a week or two ago on improved power delivery performance on my 330i (sport, 6-speed) - attributing it to break in. I take it back.

I'm still experiencing erratic power. When I mean erratic, I mean that I can get into the throttle one moment, and the torque and power are right there...right into the throttle and it pulls hard. Back off and do it again, and it feels totally flat, as if the spark advance is being retarted - in fact, you can almost detect a power increase as you back off the throttle slightly. More often than not, I don't get a great rush of power.

I can't figure out if this is a problem with the electronic throttle, valvetronic, vanos, or air temperature (heat - it seems to perform more consistently in the evening in cooler air).

Every car I've owned prior has been a turbo 4 cylinder ('92 Eagle Talon Tsi, '98 Audi A4 1.8T). Turbo's are notorious for being affected by air temperature for obvious reasons - as such, each of these car's power varied relatively significantly due to the outdoor temperature. I don't really believe that air temperature is the culprit here, but I had certainly expected power delivery of a normally aspirated in-line 6 to be more consistent.

I'm not satisfied. When it does pull, it pulls hard - addictively hard. If the engine performed consistently in this manner it would be awesome. As is, more often than not, it's flat. That bites. I'm going to talk to the dealer about this when I take it back in for the bluetooth module on backorder (its not working either).

I welcome your thoughts and feedback - particularly if any of you are experiencing similar problems.

[RachelS]

I posted this before, my car run 100% better in temps of below 72 degrees.

I think they will file a puma on this for us. ask your dealer to do the same.

I think they need more R&D in warmer climates on this car. It has been a hot summer so far.

[collinp]

I've got a 330i steptronic. Like others I have noticed an intermittent hesitation and lurch from standstill, but no problems with power delivery once the car is rolling. The temperatures here haven't been too hot (low 70s), though.

- Collin

[CorporalCarrot]

Folks

I wonder is it a combination of the temp and the fuel you use over there. Practically all complaints (AFAICS) about hesitation etc have come from the USA.

What RON fuel do you use? Because over here (Ireland) all the fuel is 98 RON and the manual says

"The Petrol engines are designed for RON 98 fuel. They may be run on RON 91 fuel with a decrease in engine power and an increase in fuel consumption".

Isn't most US gasoline between 89 and 91 RON?

Now maybe I am barking up the wrong tree here. I don't know if BMW tweak the engines differently depending on the most likely fuel type in whatever market its destined for. Maybe someone who knows could let us know.

C

[romeo26]

well i heard they flash a the car when it gets over here from europe! so that can be a problem. the us has stricter emmisions, and the highest octain here in cali is 91 but i think they get 93 in florida!!

[E90Fleet]

Originally Posted by CorporalCarrot

Folks

I wonder is it a combination of the temp and the fuel you use over there. Practically all complaints (AFAICS) about hesitation etc have come from the USA.

What RON fuel do you use? Because over here (Ireland) all the fuel is 98 RON and the manual says

"The Petrol engines are designed for RON 98 fuel. They may be run on RON 91 fuel with a decrease in engine power and an increase in fuel consumption".

Isn't most US gasoline between 89 and 91 RON?

Now maybe I am barking up the wrong tree here. I don't know if BMW tweak the engines differently depending on the most likely fuel type in whatever market its destined for. Maybe someone who knows could let us know.

C

Talking fuel octane between the USA and Europe always becomes confusing

Europe shows RON on the pumps
USA shows [RON+MON]/2 on the pumps

So 92 in the USA is around 96 to 98 in Europe



Also remember the USA cars have a number of differences to their 330i engines compared to europe. You can instantley see apart a USA and Euro 330i by just looking at the air intake or oil water heat exchanger.

So a problem can exist on one but not the other


Also this sounds like a slight glitch that can probably be fixed with a software update when it comes out.

But you should report it to the dealer who will tell BMW, the more people report it, the quicker the solution comes out

[bobnaz]

Try turning off your traction control. The car will dog you if your in a hard turn.

[David328M-Sport]

we have the premium unleaded @ 98 ron here in australia. i have been using it since 1992 in my e36. there is even a 95 ron fuel.

maybe that's why the US lesser ron fuel gives the 330 cars a sense of underwhelming performance feel as posted elsewhere. even the manual states that with less than 98 ron.

[AudiA4]

I've only used 93 octane here in the U.S. I'm unsure how that translates to RON.

[E90Fleet]

Originally Posted by AudiA4

I've only used 93 octane here in the U.S. I'm unsure how that translates to RON.

USA 93 would be about the same as Euro and Australian 98 RON

[E90Fleet]

Originally Posted by David325Australia

we have the premium unleaded @ 98 ron here in australia. i have been using it since 1992 in my e36. there is even a 95 ron fuel.

maybe that's why the US lesser ron fuel gives the 330 cars a sense of underwhelming performance feel as posted elsewhere. even the manual states that with less than 98 ron.

The USA 92 and 93 are roughly the same as your 98 RON

[hwkdrvr]

I am certainly not a car expert, but with the complexity of todays engine management systems, as well as emissions controls, I would bet your problem is software related or one of your sensors has gone bad. A trip back to the dealer for some diagnostic work should locate the culprit.

HTH

M.

[svengali]

There is also a version called "TRON" instead of "RON". Have you guys tried that one, and if so, what are your comments?

[AudiA4]

I very much appreciate the input, but my core question is if this is anything anyone else is experiencing, or is everyone else observing fairly consistent (and aggresive) power delivery? Note that I expect some power variation obviously, but mine seems quite broad and inconsistent.

Thanks!

[stressdoc]

I have never experienced a power variation like you are describing for any of my BMWs, but no experience (yet!) with the E90. I would test the hypotheses suggested on the list, varying outside air temp, warm-up, gas octane, DSC, etc. Another possibility is the air conditioner.

[bobnaz]

Originally Posted by AudiA4

I very much appreciate the input, but my core question is if this is anything anyone else is experiencing, or is everyone else observing fairly consistent (and aggresive) power delivery? Note that I expect some power variation obviously, but mine seems quite broad and inconsistent.

Thanks!

Not me.

[carlosng]

Originally Posted by AudiA4

I very much appreciate the input, but my core question is if this is anything anyone else is experiencing, or is everyone else observing fairly consistent (and aggresive) power delivery? Note that I expect some power variation obviously, but mine seems quite broad and inconsistent.

Thanks!

I experinced the same and post a thread too.
I think is the ecu programming...I drove a 325 loaner from delaer and it is even more responsive

[shoread]

I have a UK spec 325i SE (manual) produced Oct 05.

I'm not entirely happy with my engine prformance either.

Originally put it down to not being run-in, now has 4000 miles under its belt and has improved, but still not quite right I don't think.

Sometimes there feels a slight hesitation in acceleration, a bit like turbo-lag (though of course car doesn't have a turbo).

Problem seems to usually be between 2000 & 3100 rpm.

Car just doesn't quite seem as instyantly responsive to throttle press as I would expect, it comes on stream later but there is a slight delay. An, a bit like you, it soemtimes feels as though easing back on throrrle for a while may help.

I reckon its iether got to be a software glitch, or maybe a sensor such as mass-air-flow or engine / air temprertaure sensore. Or maybe this knock sensor, which I hera has given problems on some E46 (thouhg my old E46 was fine) and so retards ingition slightly, but sometimes when it doesn't need to.

Also my fuel consumption isn't as good as I expected. Got average of 32-33 mpg on my E46 325i (manual), weas expecting the valve-tronic to lift it to 34/35/36 mpg on my E90, but I seem to only get about 30-31mpg.

Anyone got any ideas. Is it likelt to be one of the sensors I've mentioned, could it be a fault with valve-tronic. Or maybe there could be an injector not quite in spec.

Anyone got experience of this? Especially if you've taken it in and got it resolved?

[06330i]

try putting some racing fuel in like 98 oct. here in michigan theres only a few places that carry it, but if u get it, car runs great

[jflecha]

I have step and the car feels wimpy unless I'm in DS.

I'm assuming thats why the car gets good mileage (low revs), so I'm not too concerned with the lag in regular drive.

[fletcher969]

I'm at 1600 miles, and for about 1400 of those I've noticed a distinct flat spot most noticably between 1st and 2nd, between 3000-4500 RPMs. That one is consistent regardless of temperature, etc. What I've also noticed, though more variable and sporadic, is much as is described by the OP in that you feel a surge of acceleration if you back off slightly. Sometimes though, it just seems to acccelerate a bit like it can't make up its mind if it wants to match my foot, or not, often just suddenly increasing in power from one instant to the next. flattening out the next. I hate to think I'll have to take it in to have it looked at, but I will, and I expect I'll have one of those types of problems they'll claim isn't there, or refuses to show up when they look her over. Ugggh!