2002 z3 3.0 stall on approach to junctions

[id101]

My 2002 z3 3.0 stalls on approach to junctions, not every time but it was getting worse.

It starts up straight away and idles fine.

It's been running well for about a year after a raft of lean codes with most pipes, fuel pump and filter, o2 sensors, MAF changed.
The only thing of late was running a bunch of redex through after just failing MOT on emissions and then passing afterwards.

Any thoughts or obvious fixes?

 

[id101]

My 2002 z3 3.0 stalls on approach to junctions, not every time but it was getting worse.

It starts up straight away and idles fine.

It's been running well for about a year after a raft of lean codes with most pipes, fuel pump and filter, o2 sensors, MAF changed.
The only thing of late was running a bunch of redex through after just failing MOT on emissions and then passing afterwards.

Any thoughts or obvious fixes?

Also if you catch as the revs fall and give it a blip on way down it stops it cutting out. But as i say not everytime.

 

[Eddie Zedder]

Sounds like classic symptoms of camshaft sensor failure. Best put a code reader on though to verify.

 

[colb]

I think @Eddie Zedder may well be on the correct cause of your symptoms, camshaft sensors don't always set a code when they start failing so you may not have a code set if you scan the car for codes. I had same symptoms with my Ssangyong Korando stalling out at junctions it wouldn't set a code and had me stumped, as it was still under warranty it went to the dealer, took them three weeks of faffing about until it finally it set a code for the camshaft sensor, new one fitted and instant cure. Its also worth noting that a failing sensor will affect the car starting, it will crank over longer than normal, how is your car starting, first turn of the key or is it taking longer to crank till it fires up?

 

[id101]

I think @Eddie Zedder may well be on the correct cause of your symptoms, camshaft sensors don't always set a code when they start failing so you may not have a code set if you scan the car for codes. I had same symptoms with my Ssangyong Korando stalling out at junctions it wouldn't set a code and had me stumped, as it was still under warranty it went to the dealer, took them three weeks of faffing about until it finally it set a code for the camshaft sensor, new one fitted and instant cure. Its also worth noting that a failing sensor will affect the car starting, it will crank over longer than normal, how is your car starting, first turn of the key or is it taking longer to crank till it fires up?

First turn every time at the moment

 

[colb]

Probably still worth changing it given the age of our cars these days. Probably a good idea to take the idle control valve off and clean it out with carb cleaner spray, if you shake it in your hand it should rattle when its clean. Reinstall and see if that improves things.

 

[Scooblitz]

As soon as I read your first post I thought camshaft sensor. Mine did something similar a while back after its visit to the ‘hospital.’

It would idle quite poorly and cut out as it couldn’t sustain the revs.

@Stevo7682 Caught it whilst he was getting it back on the road. Something tells me the sensor is buried a little.

@GazHyde Did an article on replacing his on a TU engine. Clickety on Article Here

Stevie

 

[id101]

As soon as I read your first post I thought camshaft sensor. Mine did something similar a while back after its visit to the ‘hospital.’

It would idle quite poorly and cut out as it couldn’t sustain the revs.

@Stevo7682 Caught it whilst he was getting it back on the road. Something tells me the sensor is buried a little.

@GazHyde Did an article on replacing his on a TU engine. Clickety on Article Here

Stevie

Im more a driver than mechanic, I know my limitations is it a similar job/location on an m54 engine

 

[Scooblitz]

As @colb Has mentioned, Idle Control Valve could also be the culprit.

Had issues with my first Z3, an M44 engined car where It also idled poorly. Felt I needed to blip the throttle as It shoogled at the lights trying to maintain rpm. The car service history contained receipts for a few trips to the garage for this reason.

I’d expect one of these is also going to be a contributor to your emissions fail at MOT as the 6 cylinder TU engines tend to be fine with the right air and fuel mix.

 

[colb]

Location of sensors here

RealOEM.com - Online BMW Parts Catalog

BMW parts Z3 E36 Z3 3.0i Cylinder head Vanos

www.realoem.com

Items 5 and 18 in the diagram, Item 5 is the exhaust camshaft sensor, item 18 is the inlet camshaft sensor. My hunch would be to replace item 18 the inlet sensor.
Part number

12147539165

Choice on ebay, go for a decent Brand like Febi or Delphi, there is a Lucas brand one on there for a decent price if you want to gamble on the Prince of Darkness!!
https://www.ebay.co.uk/sch/i.html?_nkw=12147539165 &_sacat=0&_from=R40&_trksid=m570.l1313