Throttle issues - S54/Z4M
Discussion
My Z4M is playing up intermittently. When coming off the the throttle it is very jerky, and jerky when back on it again. If I plant the accelerator it clears the jerkiness for a short while but it comes back. The car will eventually throw up the EML light, DSC light and yellow handbrake light and go into limp mode or just slowly come to a halt. Turning the ignition off and back again again clears the lights and it drives normal again for a short while. I think there must be a duff sensor but its not storing any fault codes. My local Indy stripped the throttle bodies and found the levers to be very stiff. He freed them up and this did make the throttle a bit smoother. It's not cured the problem though.
Any ideas on which sensors to start with or what could possibly be causing the problem?
Any ideas on which sensors to start with or what could possibly be causing the problem?
I had the same issue with my E46 M3 last summer.
Problem lied with the throttle linkage, throttle actuator and the throttle position sensor under the air box. I had a Mondial assistance van which came to me and changed the most accessible throttle position sensor on the front of the engine which did nothing. The car was then taken to a dealer who changed all the previously mentioned bits and everything was fine.
Problem lied with the throttle linkage, throttle actuator and the throttle position sensor under the air box. I had a Mondial assistance van which came to me and changed the most accessible throttle position sensor on the front of the engine which did nothing. The car was then taken to a dealer who changed all the previously mentioned bits and everything was fine.
Easty-5 said:
No idle problems what so ever. Idles spot on. Only idles terrible once it has thrown up the warning lights.
Sounds like MAF then as that is what my old one did. Drive perfectly then threw the error and idled erratically until the light went out - which could be anywhere from next time I started it to 4-5 days. Worth getting fault codes read.
Herbs said:
Sounds like MAF then as that is what my old one did. Drive perfectly then threw the error and idled erratically until the light went out - which could be anywhere from next time I started it to 4-5 days.
Worth getting fault codes read.
I have ad the codes read and none have been stored. All clear. I have just bought an almost new MAF sensor so with a bit of luck that may solve it. Although, with my luck, I doubt it,Worth getting fault codes read.
Babw said:
I would be very surprised if this wasn't a throttle (sensor, actuator) fault.
Have you tried gently increasing throttle input? Does that still cause the issue just the same as when you plant your foot down?
I'm leaning that way myself. It is have only noticed it jerky when applying throttle after it has been jerky when decelerating, although I haven't really tried. You can coax the car into doing it by coming very slowly off the accelerator. It only really happens once you ave been driving for a while also.Have you tried gently increasing throttle input? Does that still cause the issue just the same as when you plant your foot down?
Went out for a run to Ullapool yesterday. Car ran fine all the way there but started to play up on the way home. The throttle became very jerky again and felt almost like a misfire. I revved it to clear it and got an almighty backfire from the exhaust. It then drove fine for a while before being jerky again. A quick rev of the car would clear it. Eventually the car would throw up the aforementioned warning lights, although this time it was doing it at anytime, not just when coming off the throttle. Could this potentially be MAF related or does it still sound like a throttle issue? When I turn the key to Ignition II the EML light and DSC light stay illuminated but disappear once I start the car. Is that normal? I can't remember.
I think I will buy the diagnostic cable from BM Technic. Will I be able to pull the codes with the engine running?
I think I will buy the diagnostic cable from BM Technic. Will I be able to pull the codes with the engine running?
Yes I reset the throttle. To throw another spanner in the works, the car only seems to go it after prolonged use or when driving hard. I drove home from Invergordon to Aberdeen last night (130 miles) and the car didn't skip a beat. When I got home I tried to get the car to play up but it wouldn't do it. I plugged in my generic OBDII scanner and it is saying that there is a fault there but it won't give me a code. It just says 'N/A 01'. The car is being left with my Indy today so hopefully they will get to the bottom of it.
3 tps - front of engine, under intake mani and the throttle pedal itself is the third.
Replace the one at the front and take it for a spin. My guesses are on the one under the intake but no harm trying the most accessible one first. The throttle pedal is the least likely.
Let us know how it goes.
Replace the one at the front and take it for a spin. My guesses are on the one under the intake but no harm trying the most accessible one first. The throttle pedal is the least likely.
Let us know how it goes.
Edited by Babw on Wednesday 7th August 15:18
Update - Just heard from my Indy. Throttle actuator is goosed and they recommend changing the TPS at the top of the engine. £371 ex Vat for actuator. Didn't get the price for the TPS. Actuator is on back order so 10 days for that to arrive.
In the meantime, my Indy is away to phone my warranty company. No doubt they will wrangle out of it so looks like I'm set for a nice £7-800 bill. Got to love performance cars.
In the meantime, my Indy is away to phone my warranty company. No doubt they will wrangle out of it so looks like I'm set for a nice £7-800 bill. Got to love performance cars.
Rosco71 said:
Hi, just come across this thread searching for similar issues with E46 M3,did the throttle actuator sort the problem Easty5? I have changed plugs,coil packs both throttle position sensors,plus new pedal,still have the very same symptoms! Cheers
Yes it was the throttle actuator. Once replaced it was good as new again. Very common problem with the S54 unfortunately. Gassing Station | M Power | Top of Page | What's New | My Stuff