Z3 8valve sticking throttle

Tyres, exhausts, suspension, strut braces, air filters, brake pads/rotors and anything else for 'dawn raiders'.
Post Reply
stephenwj
Joined: Wed 24 Apr, 2013 22:44
Posts: 14

  Z3 roadster 1.8 TU
Location: Monmouthshire UK

Z3 8valve sticking throttle

Post by stephenwj »

Hope somebody can help with this fault I have a 1999 Z3 1900cc 8V the throttle sticks initially when you press the throttle from tick over whilst driving there is no problem until you stop at a junction and go to pull off, if you press the throttle with engine turned off there is no problem throttle cable and pedal are working perfect, the car has only done 42000 miles.
Del
Joined: Sat 19 Nov, 2011 18:35
Posts: 2136

  Z3 roadster 1.9

Re: Z3 8valve sticking throttle

Post by Del »

For thoroughness it is always best to plug in a diagnostic error code reader just to see if the ECU has logged a fault from a sensor e.g. throttle position sensor. Failing that and assuming the cable is OK and not sticking, I would suspect the circular "butterfly" valves inside the throttle body. They can get black carbon gum around their outer circumference which can cause them to stick and not open/shut smoothly with the pedal operation - relatively easy to remove and clean with carb cleaner and cotton wool buds etc. :)
bertiejaffa
Joined: Fri 26 Jul, 2013 09:28
Posts: 1733

  M roadster S50
Location: Manchester

Re: Z3 8valve sticking throttle

Post by bertiejaffa »

Its always worth replacing the throttle cable - £20 odd from BMW and easy to fit - the difference is beyond words
Here come the girls.....
Image
My //M Refurb
My First Zed Journal
stephenwj
Joined: Wed 24 Apr, 2013 22:44
Posts: 14

  Z3 roadster 1.8 TU
Location: Monmouthshire UK

Re: Z3 8valve sticking throttle

Post by stephenwj »

Thanks Del you were right on track with the build up of carbon around the butterfly in the throttle body, all cleaned and running perfect.

Regards
Stephen
User avatar
kjb1
Joined: Thu 04 Feb, 2016 11:12
Posts: 238

  Z3 roadster 1.9

Re: Z3 8valve sticking throttle

Post by kjb1 »

stephenwj wrote:Thanks Del you were right on track with the build up of carbon around the butterfly in the throttle body, all cleaned and running perfect.

Regards
Stephen
little how to on the removal / cleaning process? be keen to do mine.


Sent from my iPhone
stephenwj
Joined: Wed 24 Apr, 2013 22:44
Posts: 14

  Z3 roadster 1.8 TU
Location: Monmouthshire UK

Re: Z3 8valve sticking throttle

Post by stephenwj »

I managed to clean the throttle body by removing the rubber air intake pipe from the throttle body holding the throttle open by hand then cleaning around the butterfly with carb cleaner using a small rag it worked perfect.

Regards
Stephen
Post Reply