torque-less wonder(long rant)

[taggart]

That was the perfect description for my 525i. Anything less than 20% on throttle didn't do much...no engine whine, barely an increase in rpm or speed, no errors, no drama. Putting it in Sport mode only yielded a modicum of improvement. It was getting to be boring that I was thinking of getting one of those Sprint boosters to upp the driving enjoyment.

Fast forward to yesterday. Got me a brand new DISA valve from Tischer BMW as I noted the old valve opening on light application of throttle. Took out the old one and was dissapointed comparing them both. Except for the thicker gasket on the new one, the flap feels just as sturdy and snaps back with the same resistance. Same sound too from the diaphragm. Bummer since I spent almost $200 on this electronic gizmo. Oh well at least it's new. Putting the new one into the manifold was noticeably harder from the thicker gaskets. Started the car and it idles fine as before replacement. Noted a change in engine note but thought it was just my imagination. Went for a drive. What was a routine test drive became a revelation. 10% throttle application yielded near instant response. Looked at the speedo and it seems to climb faster than before at city speeds. On stoplights, I am able to pull away from the regular cars at less than 20% TP whereas I used to get left behind with the same application unless I put it in Sport. And then it dawned on me. I was in Drive mode! Wow! The car is now a different beast! Engine induction noise is noticeable now(low growl) for some reason. Freeway experience was no different, with the car now obeying my throttle inputs like a smitten schoolgirl. Too early to tell on mpg, but it seems to be holding above 20mpg in the city so far. All in all, it's the best $200 spent thus far.

Hope my experience helps my bimmerforum fellows with similar issues.

[ExCon]

Oh Snaps, this is one of my peeves. I will look further into this little gizmo. Thanks for the rant, I mean informative post.

[taggart]

You're welcome ExCon! One thing I wasn't able to test though is if the old DISA was really bad or it's just the gaskets. Good luck!

[Poolman]

Well--if you can change out the DISA valve you can change out your Vanos seals
There is where you will really find lost power--changing out the Vanos seals will make you think that your car is new again. Click on the link and have a good read.
http://www.beisansystems.com/procedu..._procedure.htm

[taggart]

@Poolman - Did those 15k ago. When I did mine, I also had no idle issues but as preventive maintenance. Didn't notice much difference except for maybe a very slight torque improvement at the lower rpm range. Not as dramatic as the DISA valve replacement in my case but still worth the $60 and peace of mind. Yes they probably go hand-in-hand since they both seem to affect low end torque.

Well--if you can change out the DISA valve you can change out your Vanos seals
There is where you will really find lost power--changing out the Vanos seals will make you think that your car is new again. Click on the link and have a good read.
http://www.beisansystems.com/procedu..._procedure.htm

[jamesdc4]

Congrats on a successful upgrade/fix!!

[taggart]

Thank you sir!

[ExCon]

Very nice, I had already done my reaserch and the Vanos seal kit was in line but now im going to throw this gizmo onto the list of preventive manitnance.

[taggart]

Update since the install:

1. Car seems to hold speed/revs longer with foot off gas pedal. Now I have to step on the brakes more.

2. Transmission upshifts a lot faster. This is probably due to the tach moving a lot faster up to the 3k mark. Also less marked difference between Drive and Sport mode. Also goes up to 80mph faster now.

3. Gas mileage has gone down a bit. Currently at 260miles with at little over a quarter. OBC indicates 18.6mpg. Less difference noted between OBC city and freeway mileage. Could be the new car behavior now makes my throttle inputs leadfooted.

Will update if I notice any other changes.

[gjVah]

stupid q, but does my car have a that disa thingy?

[taggart]

stupid q, but does my car have a that disa thingy?

That's actually a good question. Anyone?

[AnotherGeezer]

My guess would be no.

and why..

http://www.oembimmerparts.com/catalo...50/7506243.htm

[Doru]

v8 don't have Disa valve. I's a different air intake design alltogether

[billzcat1]

What the F does DISA stand for?

[carjoe]

3. Gas mileage has gone down a bit. Currently at 260miles with at little over a quarter. OBC indicates 18.6mpg. Less difference noted between OBC city and freeway mileage. Could be the new car behavior now makes my throttle inputs leadfooted.

Will update if I notice any other changes.

Whoa, I get about 20MPG in the city my 540.

Glad to hear your car is working better than ever!

[taggart]

What the F does DISA stand for?

http://www.mbmw.com/bmw_technical_acronyms.htm

Whoa, I get about 20MPG in the city my 540.

Glad to hear your car is working better than ever!

Yeah traffic lights every 300ft or so plus LA traffic sucks.

Thanks!

[Jason5driver]

Good thread...

$200 part...
http://www.eactuning.com/parts/produ...ls/11617544806

[taggart]

Thanks Jason!

Update: I've since replaced the tensioners and the car went back to being a bit slow. The old tensioners spin freely if noisily while the new ones stop on a dime. Didn't think I'll be losing power with this.
Cleaning the accelerator module inside the gas pedal assembly has since brought the throttle response back up though! Guess that too was out of spec for a while.

[bimmerfiver]

Thanks Jason!

Update: I've since replaced the tensioners and the car went back to being a bit slow. The old tensioners spin freely if noisily while the new ones stop on a dime. Didn't think I'll be losing power with this.
Cleaning the accelerator module inside the gas pedal assembly has since brought the throttle response back up though! Guess that too was out of spec for a while.

Huh? Clean it? With electronic cleaner? Do you think it's placebo? This is a strange one on me.

I have a 2003 525.
First thing I did when I bought is was wash, wax and tint windows.
Next was off to dealership for DINAN chip for engine.
Next was DINAN chip for automatic tranny.
Next was an air filter that didn't come with the 'brillo pad' extra foam.
Next was clean the throttle body out.
New plugs.
New coils.
New belts and tensioners.
New fuel filter.
New throttle intake boot to eliminate vacuum leak.
VANOS seals next.
And then you play with your suspension and brakes to make them more responsive.

That's all you can do with a 2.5 or do what Gumbi did.

I don't fathom how new belts and tensioners could fight you...old, chirpy rollers have bearings that drag, extra friction. And this gas pedal module, I am unclear how cleaning it makes one's gas pedal seem more responsive.

[taggart]

[quote=bimmerfiver;20549142]

Huh? Clean it? With electronic cleaner?[quote]

Yep.

Do you think it's placebo? This is a strange one on me.

I don't think so. Doing so made throttle response noticeably more linear....before it's more like flat until 30% TP. Now it responds to minute throttle input. Downshifts at lesser throttle input too. Why strange? The module is a potentiometer that could go out of spec. Same thing with old stereo systems with volume pots. Crackles until cleaned.

I have a 2003 525.
First thing I did when I bought is was wash, wax and tint windows.

Good to know we almost have the same mods except for air filter, cleaning throttle body and new coils.

That's all you can do with a 2.5 or do what Gumbi did.

I don't fathom how new belts and tensioners could fight you...old, chirpy rollers have bearings that drag, extra friction. And this gas pedal module, I am unclear how cleaning it makes one's gas pedal seem more responsive.

My old tensioners weren't that bad(no noise with engine running)...they spin a lot more freely(albeit with noise) than the new tensioners...an incidental finding while changing my belts. That change plus the poor throttle feedback my car must have been experiencing due to the accelerator module issue at low throttle input made the symptoms more acute I guess. That the module could go out of spec may be due to time and moisture(the location isn't airtight). All I know is that worked for me for now. I only hope it's made of better stuff than those old stereo pots which you have to clean again after a week or so.

[taggart]

Just wanna update this thread. So far so good with the fixes above. Car doesn't bog down while making a left or right against opposing traffic anymore. Runs smooth and no codes.

[ssanmor]

Very interesting thread, I have been following it...
Some time ago I disassembled mine and found it was tight (as it should, I think!). Also checked that it closes when idling and opens when rpm increase. I even checked that it closes later when under load.
Did you check that with the old one? It seems weird that it was apparently good and you noticed such a difference. Gives some hope to me, but...

[Poolman]

There was probably a vacuum leak with the old unit, that might have been the reason you didn't feel the Vanos seals weren't helping the engine as they should. It's been noted many times about the effects of vacuum leaking around the DISA unit. The new part you installed sealed the intake up again as it should be.

[gnilson]

So might I be able to get away with a fresh gasket? I'm thinking cheap.

[taggart]

Some time ago I disassembled mine and found it was tight (as it should, I think!). Also checked that it closes when idling and opens when rpm increase. I even checked that it closes later when under load.
Did you check that with the old one? It seems weird that it was apparently good and you noticed such a difference. Gives some hope to me, but...

What I've learned from this is the rpm the flap opens and closes at is important. On my old one, it does so prematurely.(less than 2000rpm) I didn't bother to check if it closes back up at load since the above symptom was enough reason for me to replace the valve.

There was probably a vacuum leak with the old unit, that might have been the reason you didn't feel the Vanos seals weren't helping the engine as they should. It's been noted many times about the effects of vacuum leaking around the DISA unit. The new part you installed sealed the intake up again as it should be.

So might I be able to get away with a fresh gasket? I'm thinking cheap.

Maybe I could have saved the money with the gasket fix(if that was indeed my problem) but after reading about the DISA pin going AWOL and doing expensive damage, I'm glad I changed to a new one.