Variable tach issue warmup dial on the fritz

[BigRussia]

Just picked up my 2nd e9x M3 a few weeks ago, 2008 E90 6mt w 108k miles, and last Sunday 10 minutes into a drive I noticed the variable tach warmup dial was stuck at 4k even though the car was fully warmed up (oil temp around 200F). Turned the car off and on a few times when parked but no luck, came back after dinner and was back to normal (or just stuck at 8k maybe). Then all this week it’s been getting stuck at random rpms, mostly 7.6k… I searched the forum and only found one old thread where it was someone looking to buy a modified car w electrical issues and was stuck at 8k but no follow-up/resolution. Seems maybe it’s a new issue as these cars are approaching 20 years old? My old 2011 E92 never had any issue like this but was also much newer at the time I guess. Car is basically stock only AA exhaust and tune per previous owner.

I pulled codes with INPA and there was nothing relating to it, and reset the battery this morning and all it did was now have it be stuck at 6k rpm after first going all the way to 3k when started up the car after replugging the battery terminal. Even with the car off now it doesn't go back to the off position (last pic). Anyone experience this issue? Does the cluster stepper motor for the dial need to be replaced maybe? Thanks

[kolosy]

Is it actually cutting fuel at that limit when warm? Or just stuck?

[BigRussia]

No, doesn’t seem to be forcing a lower rev limiter thankfully, and the oil temp gauge seems to be working fine and as expected; I’ve been looking at that for warming up the car before any spirited driving.

[BigRussia]

Guess no one else has and this happen? Since resetting the battery I've driven the car 3 times; right after the dial worked normal again and figured maybe the battery reset did the trick, but then 2nd drive last night got stuck at around 7k again (like in pic #2) and I could see a slight twitching like the motor was trying to move the dial past that position, then this morning it was working fine again slowly going up to the fully warmed up position and was there once the oil temp got to just over the 1/4 dot on the gauge.

Since it seems like a mechanical issue I'm thinking to pull the cluster out today and see if maybe somethings impeding the dial and motor, i doubt the solder or connection is bad but worth a look if i have everything out and apart

[BigRussia]

So after nearly 2 months of it only happening occasionally (usually dials redline stuck around 6k-7.6k rpm) and just dealing with not letting these these occasional ‘glitches’ bother me since would resolve itself next time i drove the car, the problem has now gotten the worse it’s ever been. Last night the variable warmup dial is now stuck at 4k rpm, didnt even know it can go this low lol. So much that theres empty blank space showing before the tach’s 8250mark is! It didn't resolve itself overnight or unplugging the battery this morning… So again wondering if I’m still the only e9x M3 owner that’s having issues with this? Could it be the AA tune? Or is it something mechanical with the stepper motor?

Edit: turned on the car after leaving the battery unplugged for over an hour and the dial swept even further into the other direction, now all red from 0 to 3k rpm..

[BigRussia]

Coldest running S65 in the game 😎🥶


No but seriously.. is this forum dead? No one has had this happen on their car or has any insight at all? Could it be the AA tune causing this?

[spammysammich]

If nobody has reported this in 17 years, sorry homie. I would ask your tuner first if they think anything in the coding might have done it. Has search really come up empty? Bummer.

[krudmunk]

do you have history on throttle actuators?

can you flash stock tune and see if the issue persists?

[RocketyMan]

That's crazy. Def seems like a mechanical issue with the KOMBI. I would just get a donor one off ebay and code it--but that's just me.

[Scrippy]

Have you tried any resources in INPA or ISTA? In ISTA you can run procedures on any ECU. I would look into Kombi functions. For sure there is an ECU reset but I betcha there are other functions for testing.

[RocketyMan]

Originally Posted by Scrippy

Have you tried any resources in INPA or ISTA? In ISTA you can run procedures on any ECU. I would look into Kombi functions. For sure there is an ECU reset but I betcha there are other functions for testing.

Yeah good idea! Def worth a shot using ISTA to do some gauge sweeps and what not. Maybe some functionality can return...?

[BigRussia]

Originally Posted by spammysammich

If nobody has reported this in 17 years, sorry homie. I would ask your tuner first if they think anything in the coding might have done it. Has search really come up empty? Bummer.

Yup totally empty searches throughout my time with this issue :/ and I bought the car with the AA tune on it, previous owner had it done at Active's HQ here in Miami. I contacted them of course, but no reply or response lol. Not suprised as im sure theyve fully moved on from the E9x/S65 platform and doubt anyone working there currently would have expereince with their now ancient S65 tune.

Originally Posted by krudmunk

do you have history on throttle actuators?

can you flash stock tune and see if the issue persists?

I do, one of the previous owners had them done, about 30k miles ago now. I dont have the stock tune since got the car with the AA tune.

Originally Posted by Scrippy

Have you tried any resources in INPA or ISTA? In ISTA you can run procedures on any ECU. I would look into Kombi functions. For sure there is an ECU reset but I betcha there are other functions for testing.

I have INPA! Didnt think to try that yet though, since I figured needed ISTA for any E9x procedures besides just reading and clearing fault codes (even then my INPA install is missing translations so i have to use google lens when reading the E90's fault codes lol)