Sound Of Speed
This is seriously one of the best mods I've done
M52TUs have a problem where you hit the clutch and the RPM stays in place for a bit, making it really annoying to upshift. It'll jerk if you don't shift really slow.
M52TU = the E46 323 and 328, z3 2.3 and 2.8s, and later 528s.
Went to the dealership today to see if they'll do anything to fix this problem:
http://forums.bimmerforums.com/forum...8&postcount=32
All M52TUs have it, really annoying and causes jerky or slow shifts. Dealer wanted to charge me to diagnose it, about $100 for parts, money for installation, and more. I said F that, I'm gonna fix it myself.
Alright, so i wanted to ground the switch to fix it.
I took out all the covers and and the metal plate to expose everything. You then need to unplug the yellow harness
Notice the car won't start now. The harness has 3 wires, one power wire and 2 grounds. One of the grounds is to start the car and the other for changing gears while driving. You want to ground the starting ground.
So with a multimeter, I figured out which one is the one to start the car, and crimped both wires together. You're just connecting these 2 wires together to ground it and make it "always on"
After you connect the wires together, make sure everything is nice and tight.
DO NOT plug the harness back in, just leave it out.
It'll look like this
Start the car to make sure everything works. Then put everything back together.
Now go for a test drive, you will notice your RPM doesn't hang when you hit the clutch, it goes down right away. Now the ride will be nice and smooth.
I also took off that annoying speaker that makes noise when you have the door open with the key in.
Former Mod
You should have installed more cowbell while you were in there.
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License Revoked
^^HAHAHHAHAHAH Lauren - jesus christ.
Oh man, finally fixed that crap (originally typed s*** but realized thet Ghery actually started a thread outside of OT for the first time ever). Good job Ghery.
Sound Of Speed
I guess nobody cares... sigh
It makes driving the car MUCH smoother
Z-Day Master at Arms
Good mod, if I had one, it would already be long gone, cause that blows ass.
ლ(ಠ益ಠ)ლ
Do S52s have that switch or is it the CDV that makes my RPMs hang?
Z-Day Master at Arms
S52 does not have that switch, CDV may be your culprit. UUC Stainless steel line and never look back.Originally Posted by StarReaver
Sound Of Speed
S52s don't have this problem.
I noticed it after I drove my friend's S52.
YTou might have a cdv though, easy delete.
I has a z33
more performancE?
No more BMW....
Sound Of Speed
about 10 horsepower to the wheels
Member
i thought it'd at least be 30
hey question regarding wire taps, do i have to partially strip the wires before tapping it in or do i just press on it so it punctures the proctective rubber layer?
I tried doing the ladder last time and it didn't completely puncture through no matter how hard I pressed and it periodically makes contacts which was annoying so i ended up cutting the wires and soldering them together.
Member
Good info!
Sound Of Speed
You just pinch em.i thought it'd at least be 30
hey question regarding wire taps, do i have to partially strip the wires before tapping it in or do i just press on it so it punctures the proctective rubber layer?
I tried doing the ladder last time and it didn't completely puncture through no matter how hard I pressed and it periodically makes contacts which was annoying so i ended up cutting the wires and soldering them together.
There are different taps for different gauges. Next time, get a smaller one or press really hard.
Reamember to press hard on the tap and make sure its secure... that bit me in the ass when I did this and put everything back together.
I has a z33
nice
No more BMW....
Sound Of Speed
bump for the 2.8 and 2.3 guys
dasjohannfunkmeister
hey sweet! thanks for looking out - i think i have a TU, not sure 12/98 production 1999 Z3 2.8 coupe? anyone know fo sho?
i have noticed that crappy hang of the rpms while shifting - makes me feel like a nooB if i forget i have to shift like a granny, i hope this works on my car..
Sound Of Speed
Mine's is a 10/98 production coupe, pretty sure you have it too. Fix that sucker
I can get a remote start alarm now too
Member
Thanks for the write-up Sound Of Speed. I'm going to look into this.
-Phil
Member
I've got a 99 2.8 M52TU Build 9/98. I haven't looked to see if I have a
2 or 3 wire connector, but have a dumb question.
When I engage the clutch, the RPM's hang for less than a second. Its never
interfered with spirited shifting - even to the point of ripping off the shift knob on a 2-3 shift - or any time on the track. Is it this the delay that you're fixing or do others' RPM's hang for longer periods of time?
Sound Of Speed
No, I had no problems driving it hard with the delay. It's a fraction of a second, but enough to jerk regular shifts.
I chirped into second even with the delay.
Member
I have a 7/99 production date 2.3, so I guess I'm free and clear? Would the only way to tell be to do the mod anyway? I've noticed the car takes its time dropping RPM's in general but I always attributed it to the larger flywheel/engine mass/etc compared to what I used to drive. GREAT info either way though!
Thanks for the post!
Sound Of Speed
If you don't mind taking off covers under the steering wheel, there is a way to test it.
Start the car, and just unplug the harness with the car on and go for a drive. If you notice a change, you have it. There is still a tiny lag, but that's just the normal lag, shifting is smooth.
Good luck.
Member
came across this post after someone on the e36 forum was searching for a solution to this problem. I have a question or 2.
From what I gather, the 3 wires here are as follows. Ground, clutch interlock signal for starting, and clutch depressed signal which is causing the problem of hanging rpm's.
Seems to me that you have removed the switch from the circuit and shorted the clutch interlock circuit so that the ECU will allow the car to start. The problem I see here is that the car can now start when it's in gear with the clutch out.
Would it not have been easier to just cut the wire that provides the ground signal to the ECU for the hanging RPM's and leave the connector plugged in thus not disabling the clutch/start interlock circuit?
-J
Sound Of Speed
If you want to risk, you can try it I guess.
I have accidently once started the car in gear, but there was too much stress on it to even start. It can't turn it without it being in neutral, so no worries. I still always press the clutch pedal while starting the car.
Member
That's just my point... It seems by just cutting the wire, you can leave the clutch interlock circuit intact, so your car wouldn't try to start with the clutch out.
-J
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