Lucky

Since a couple of weeks ago I noticed an increasing hesitation of the engine in getting rpm from about 1500 up to 2200. Past 2200 rpm, the engine roars like before.

The defect is very evident driving in cities or secondary roads; much less along highways, where I usually speed up well above 100-110 mph using mid ranges.

My SA checked the OBD and found registered hundreds of "small turbo with insufficient pressure" events. No other significative events are recordered. Top performance are uneffected, the car gets all the rpm and reaches indicated 260 kmh with easy.

I will recover the car for a complete check up but I would like to know if anybody has had the same experience with a 535d and the possible causes. Please note that the car has been remapped (to check if there was a difference I had the original map re-installed two days ago; it works better and smoother, but the defect is still there).

olli_535d

That's the first one I hear off.

Good luck with it

0700700

this is what i experienced... sounds similar to your problems ?
http://forums.e60.net/index.php?showtopic=24024&hl=535d

BetterMakeWay

I dunno, myabe i got to know the car more and more or maybe i'm begining to get some symtoms as well. The turbo lag wich was still present from day one, as i 1st layed my right foot seeking for any sign of turbo lag, it seems it's present more and more. Sometimes i get the feeling that until 1500rpm or so it doesn't move at all and the turbo lag is huge, but maybe it's just normal and as i said i got to know the car more and more. It became as you said more hezitating, not sure if the lil turbo is loosing pressure but somehow the turbo lag became bigger it appears. As you said the engine pulls as strong as before but just more hezitant especially in D mode. In DS all of the above is cured since it stays mainly above 2000rpm which is on the peak torque aka top of the mountain

Lucky

Yes, indeed. I agree with you that it becomes more apparent as time passes and it's correct that in DS mode it's almost cured. You'll probably notice that the engine becomes more reactive and less "lazy" if you drive quite hard for a while. I suspect that the autoadaptive tranny is hugely influenced by long city drives, almost always with a very light foot and rarely exceeding 1500 rpm. So, my first impression is that there is some software related problem but that still doesn't explain the ricurrent "insufficient pressure in small turbo" defect recorded by the OBD.

And in manual mode, with a crispy driving style, the defect is undetectable. So, which solution?

dlevi67

Mmm - I was under the impression that the transmission memory is wiped out at each engine restart. Not so the drive-by-wire throttle (that can be reset very easily - engine off; key in pos 1 for 10 secs, then off for 10 secs, then start the engine).

Part of me says that it's just you getting used to the engine. When I moved from my 535i E39 to the (stock) 535d, I thought the pulling power was astonishing. 4 months later, I find it less so, but clock in hand it performs the same way.

The OBD message worries me a little, though if the remap has shifted the turbo valve control action points (shifting air flow from small to big and vice versa), it may be that? Sorry- just groping for an explanation other than "fault".

Lucky

quote:The OBD message worries me a little, though if the remap has shifted the turbo valve control action points (shifting air flow from small to big and vice versa), it may be that?


No, it cannot be anything like that. I had my original map re-installed and after that the OBD still recorded the same defect. But your suggestion about throttle reset is very interesting, I'll have a try tomorrow.

BetterMakeWay

Very interesting pov and i agree with it. Didn't know about the throttle reset function. Will also try it tomorrow. What should i expect i mean what is actually reseted?

Thank you!

dlevi67

The drive by wire "learns" how much you press on the pedal and adapts reactions accordingly, so it will give a softer pick-up if you have been driving slowly and accelerating cautiously (e.g. in town) and will make the accelerator feel more responsive if you have been jabbing it. Resetting brings back a middle-of-the-road setting.

There is a thread where this was discussed somewhat more, but I'll be dinged if I can find it. Bet you that Rudy will be on the case...

BetterMakeWay

Thank you! It's more than enough for me. I just wanted to know in which position it goes after the reset. Wouldn't it be nice for it to go in the most hardcore setting after a reset?!