Z4 engine won't idle at all, keeps stalling, runs very roughly

[theosinc930]

[youtube]https://youtube.com/shorts/rXl3_h3J840?feature=share[/youtube]

Hi, my Z4 with the M54B25 engine suddenly developed this fault where the engine keep stalling at idle, and even if I give it a lot of throttle it still runs very roughly. There's no lights on the dash and the OBD scanner revealed a thermostat sensor error and a secondary air pump error, none of which seem like the causes of this issue to me. Any ideas what it may be? I've attached a youtube link with a video of the problem.

Thanks

 

[bigwinn]

I'd be looking for either an air leak making it run lean or a fuel feed issue

 

[patriot66]

Idle Control Valve ? :?

 

[colb]

Agree with whats been suggested so far, air leak from split or holed intake or vaccum hoses need checking, also take a look at the idle control valve they can get gunked up and become sticky, a good clean out with carb cleaner usually cures that.
IOf your code reader can read live data take a look at the fuel trims, if they are high then thats a good indication of an air leak somewhere.

 

[theosinc930]

Thanks a lot guys, my mechanic took the intake apart searching for air leaks and found that the ICV was gummed up. The new one will be arriving tomorrow. Hoping it will fix it!

 

[enuff_zed]

Thanks a lot guys, my mechanic took the intake apart searching for air leaks and found that the ICV was gummed up. The new one will be arriving tomorrow. Hoping it will fix it!

Usually if it's gummed up then a spray with brake cleaner and a good shake is all it takes.
It's so simple to access I'm pretty sure I'd be trying that first.

 

[theosinc930]

Thanks a lot guys, my mechanic took the intake apart searching for air leaks and found that the ICV was gummed up. The new one will be arriving tomorrow. Hoping it will fix it!

Usually if it's gummed up then a spray with brake cleaner and a good shake is all it takes.
It's so simple to access I'm pretty sure I'd be trying that first.

I would assume it got gummed up due to oil in the intake manifold because of a bad CCV? So I guess that will need doing as well.

 

[enuff_zed]

Thanks a lot guys, my mechanic took the intake apart searching for air leaks and found that the ICV was gummed up. The new one will be arriving tomorrow. Hoping it will fix it!

Usually if it's gummed up then a spray with brake cleaner and a good shake is all it takes.
It's so simple to access I'm pretty sure I'd be trying that first.

I would assume it got gummed up due to oil in the intake manifold because of a bad CCV? So I guess that will need doing as well.

Possibly... eventually.....
But still sure a clean up will fix it for the foreseeable future.

 

[theosinc930]

Usually if it's gummed up then a spray with brake cleaner and a good shake is all it takes.
It's so simple to access I'm pretty sure I'd be trying that first.

I would assume it got gummed up due to oil in the intake manifold because of a bad CCV? So I guess that will need doing as well.

Possibly... eventually.....
But still sure a clean up will fix it for the foreseeable future.

I was told that a simple, old school BMW with an N/A straight six, manual gearbox and RWD would be the most reliable. If this is the most reliable, then I don't want to know what the most unreliable ones are like

 

[bigwinn]

I would assume it got gummed up due to oil in the intake manifold because of a bad CCV? So I guess that will need doing as well.

Possibly... eventually.....
But still sure a clean up will fix it for the foreseeable future.

I was told that a simple, old school BMW with an N/A straight six, manual gearbox and RWD would be the most reliable. If this is the most reliable, then I don't want to know what the most unreliable ones are like

Get a modern 2 litre BMW diesel- all made from cheese

 

[enuff_zed]

I would assume it got gummed up due to oil in the intake manifold because of a bad CCV? So I guess that will need doing as well.

Possibly... eventually.....
But still sure a clean up will fix it for the foreseeable future.

I was told that a simple, old school BMW with an N/A straight six, manual gearbox and RWD would be the most reliable. If this is the most reliable, then I don't want to know what the most unreliable ones are like

Well I’ve told you a reliable fix that’s free if you have a spare hour.

 

[mac27040]

i would say air mass meter, try unpluging it and see if car runs better unplugged.

 

[ronk]

I would assume it got gummed up due to oil in the intake manifold because of a bad CCV? So I guess that will need doing as well.

Possibly... eventually.....
But still sure a clean up will fix it for the foreseeable future.

I was told that a simple, old school BMW with an N/A straight six, manual gearbox and RWD would be the most reliable. If this is the most reliable, then I don't want to know what the most unreliable ones are like

It’s twenty years old!

 

[theosinc930]

Idle Control Valve ? :?

Thanks mate. A new ICV fixed it.

 

[enuff_zed]

Idle Control Valve ? :?

Thanks mate. A new ICV fixed it.

How much was that versus cleaning the old one :roll: