Low power under 2000 RPM - Vanos?

[redandgearhead]

Maybe all E34 525i's are this way, but i don't have much power from idle to over 2000 RPM. Even without the AC on there isn't much power, even floored. Once you get over 2000, it goes. The car was down for a couple of months while I decided how to repair the threads on one of spark plug holes, so I haven't driven it in a while. Maybe it was like that before the repair.

The worse case scenario I can think of his the VANOS is stuck on high RPM. Is this a possible problem? Or is this either normal or just a tune-up problem?

Thanks,

Joe Boucher

[Ross]

If the vanos had stuck you would get a rougher idle me thinks.

[DaveVoorhis]

BMW engines like a lot of spin. A 2.5 litre mill is not going to develop exciting torque at low RPM. Pretend it's a Japanese motorcycle and keep the revs up -- you'll be a lot happier.

[bubba966]

All E34 525's must be that way as that's my experience as well. Power down low requires good low end torque. Good low end torque requires larger displacements. BMW doesn't build torque monsters. Even their "big V12's" are smaller than most "small" US V8's. Even my chipped 540i M-Sport doesn't have much torque under 2,000 RPM.

An E34 is a lot of weight to move. And a NA 525 isn't going to ever provide enough torque to get it moving at a decent rate.

[repenttokyo]

my car is dead slow below 3000 rpm. above that it's still pretty slow, but it's a bit faster, and I can pretend.

[yaofeng]

Maybe all E34 525i's are this way, but i don't have much power from idle to over 2000 RPM. Even without the AC on there isn't much power, even floored. Once you get over 2000, it goes. The car was down for a couple of months while I decided how to repair the threads on one of spark plug holes, so I haven't driven it in a while. Maybe it was like that before the repair.

The worse case scenario I can think of his the VANOS is stuck on high RPM. Is this a possible problem? Or is this either normal or just a tune-up problem?

Thanks,

Joe Boucher


Check this link out,

http://www.bimmerboard.com/forums/posts/543920

I won't pretend it is the solution for you. Just do not over look anything. I have this same symptom for over a year.

[Ross]

Yup, come to think of it my old touring was a 525 and a turd off the line, throttle position meant nothing, it was just sloww until it got on the cams.
155 cubes lugging 3600#, do the math.

[Bo525i]

I chipped mine just to get a little torque below 2000 rpm.. Didn´t turn into a M5 but it sure helped! :)

[Morgenster]

Maybe all E34 525i's are this way, but i don't have much power from idle to over 2000 RPM. Even without the AC on there isn't much power, even floored. Once you get over 2000, it goes. The car was down for a couple of months while I decided how to repair the threads on one of spark plug holes, so I haven't driven it in a while. Maybe it was like that before the repair.

The worse case scenario I can think of his the VANOS is stuck on high RPM. Is this a possible problem? Or is this either normal or just a tune-up problem?

Thanks,

Joe Boucher

VANOS actually gives you more torque from 2000 to 4000 compared to non-VANOS. So lower than 2000 is normally slow.

[E34-520iSE]

You want to try driving an M20B20! Below 2000 there's next to no life in it!

HTH,

Shaun M

[spyrot1]

Ever since I put the EAT chip in, it's been quite nice low down. Doesn't have the torque that my Durango 4.7 does, but I have no issues at all low down... and it loves to rev! Loses something with the AC on, but still more than enough torque to get off the line nicely.

try some new plugs, check your fuel filter and maybe go with a free flow air filter. I use a K&N and the car feels great (i know... waiting for all the K&N bashers to add their 2 cents, but I've had K&N in all of my cars for the past 20 years and never, I repeat, never had an engine problem).

Try some fuel injection cleaner, that may help.

[whiskychaser]

Forget the tacho. Just open the window, put your foot down a bit and listen to it sing. Unless you are one of those people who really dont chew fruit pastilles you are going to smile. :)

Edit: explanation if required:

http://www.rowntrees.co.uk/commercials/beatboxer.aspx

[Brandon J]

M50tu's are slow under 2k rpm. Shewwwwt....because of that (before the S38 transplant) I had 3 chips, S50 M3 cams, changed the diff, did a lightweight flywheel (made the under 2k worse), intake, 540 MAF, injectors, etc. etc. What was great is even after all my upgrades, I was getting 28mpg average mixed highway/city.

A V12 or even the 4.4L M62tu in my e39 has changed that with good torque below the 2k rpm range. The 2.5L M50tu is what it is and does need to be above 2k rpm for drivable power. The newer BMW 6cyl have addressed that issue and have improved the 1500-2000rpm power range. If you don't have a performance chip yet, I suggest to get one as it helps with the drivability of the M50tu.