Z4-forum.com

Newbie to the forum. I've picked up a 2003 Z4 3.0i in Sterling Grey, it's got a couple of issues that I need to sort:

Central locking - will not unlock off key, but will lock using the key. This applies to both drivers and passenger side doors, boot operates fine. Same issue when using the central locking button inside the car. Is it unlikely to be the door actuator due to being both sides? Is this the dreaded GM5 fault?

Coolant light coming on after 10 mins of driving, coolant level is fine. It has had a recent coolant reservoir (before my ownership) and has literally just returned from a new water pump and thermostat and fresh coolant. The light was doing the same before the new reservoir. I've got a coolant level sensor coming - is it likely to be this?

Thanks in advance if you can help.

Edited this thread to keep a log of all the changes

1st GM5 If you're in the UK, you have venders who repair this and if you're in the USA/Canada there is a fellow in LA. area who repairs this.

2nd Try changing out the sensor 1st.

Welcome to the forum.

Welcome aboard,
Definitely sounds like a GM5 issue for the locking.
Yes you can send them off to be repaired. Not too difficult to get at either. However, there is one version called a 'Star 12' which can be more of an issue as not many places will work on them. So ideally you need it out first to check what it is.

Very surprised if the old sensor was put back in the new tank, but yes it's possible, so definitely change that first.

Whereabouts are you?
If these aren't things you fancy doing yourself there may be someone nearby who could help.

Jas- USA wrote: ↑Fri Nov 25, 2022 3:57 pm 1st GM5 If you're in the UK, you have venders who repair this and if you're in the USA/Canada there is a fellow in LA. area who repairs this.

2nd Try changing out the sensor 1st.

Based in the UK - there's a guy on eBay that repairs them, I'll try and find someone more local though.

buzyg wrote: ↑Fri Nov 25, 2022 5:19 pm Welcome to the forum.

Thank you!

buzyg wrote: ↑Fri Nov 25, 2022 5:19 pm New owner with issuesQuote enuff_zed
by enuff_zed »

Welcome aboard,
Definitely sounds like a GM5 issue for the locking.
Yes you can send them off to be repaired. Not too difficult to get at either. However, there is one version called a 'Star 12' which can be more of an issue as not many places will work on them. So ideally you need it out first to check what it is.

Very surprised if the old sensor was put back in the new tank, but yes it's possible, so definitely change that first.

Whereabouts are you?
If these aren't things you fancy doing yourself there may be someone nearby who could help.

I'm based in Kent, I'm quite happy to do some stuff by myself - although I'm used to taking VW's apart. I haven't had a "DIY" car in a good few years. I've seen the invoice and it's just invoiced as the tank so they may well have done. The car used to belong to my Father in law so I know it's history from 6 months from new. The new sensor looks like an easy fit.

T_J_G wrote: ↑Fri Nov 25, 2022 6:16 pm

Jas- USA wrote: ↑Fri Nov 25, 2022 3:57 pm 1st GM5 If you're in the UK, you have venders who repair this and if you're in the USA/Canada there is a fellow in LA. area who repairs this.

2nd Try changing out the sensor 1st.

Based in the UK - there's a guy on eBay that repairs them, I'll try and find someone more local though.

buzyg wrote: ↑Fri Nov 25, 2022 5:19 pm Welcome to the forum.

Thank you!

buzyg wrote: ↑Fri Nov 25, 2022 5:19 pm New owner with issuesQuote enuff_zed
by enuff_zed »

Welcome aboard,
Definitely sounds like a GM5 issue for the locking.
Yes you can send them off to be repaired. Not too difficult to get at either. However, there is one version called a 'Star 12' which can be more of an issue as not many places will work on them. So ideally you need it out first to check what it is.

Very surprised if the old sensor was put back in the new tank, but yes it's possible, so definitely change that first.

Whereabouts are you?
If these aren't things you fancy doing yourself there may be someone nearby who could help.

I'm based in Kent, I'm quite happy to do some stuff by myself - although I'm used to taking VW's apart. I haven't had a "DIY" car in a good few years. I've seen the invoice and it's just invoiced as the tank so they may well have done. The car used to belong to my Father in law so I know it's history from 6 months from new. The new sensor looks like an easy fit.

Yup, sensor is dead easy to swap.
The GM5 is up behind the glove-box in the left corner. On a bracket. Drop it down first as the plugs are a fiddly design to remove and easiest to see what you're doing.
There's a bloke in Harrogate who advertises for GM5 repairs on Ebay. Someone on here got his done the other day I think and back in the car within about three days!

Here you go.
viewtopic.php?p=1968293&hilit=gm5#p1968293
Check out the last post by Sludgepump

enuff_zed wrote: ↑Fri Nov 25, 2022 6:39 pm Here you go.
viewtopic.php?p=1968293&hilit=gm5#p1968293
Check out the last post by Sludgepump

Thank you, I'd already read that - I've been lurking a while.....

Hi and welcome to the forum.

Nice to know your car's history too, but we'd love to see a photo or two of it!

Hi, welcome to the forum, as others have said we like photos to look at. Yes we are simple folk here.

First week of proper ownership, so it was due a wash and wax.

Few jobs to sort as above along with a new battery, I’ll also get the wheels refurbed in the future!

Looking good

Nice car!

That's a smart looking Z4.

Thanks all, GM5 unit whipped out and sent off for repair, a new battery didn't help. Hopefully it doesn't get caught up in the Royal Mail delays. I'm still waiting for that coolant sensor I ordered over a week ago.