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2003 z4 2.5

Posted: Wed Jul 21, 2021 5:45 pm
by Gary busta Head
Hi need some advice before taking hammer to my z4 😊I’ll try and explain as best I can. Drive to holiday destination and had a few Warner lights come on but checked and all way good the more I drove the more came on but was a perfect driver and made it back 400 miles without fault. Local garage found Abs sensor and oil pick up sensor issues so change them. Drove great again 15-20 miles when stopped ticking over warning lights back on and engine starting revving up and down. Back to the shop this time fuel rail issue new one 😊 then before I collected it alternator issue, picked it up 10 miles same again when standing still, the garage then diagnosed Ecu over heating so we went for new Ecu which was the programmed to car by BMW specialist. Seemed all good sat on MOT ramp and boom gone again garage don’t want to play anymore and I’ve spent a bloody fortune😑 Any help or a box of matches would be great . Tks

2003 z4 2.5

Posted: Wed Jul 21, 2021 6:14 pm
by zriha
Hm, sorry to hear that mate, a lot of problems, seems to me not all connected, but as you are talking about sensors (yeah, they can die), what is the milage of the car?

So, to conclude, you have:
- new ABS sensor
- new OIL pick up sensor
- new ECU

And the problem continues? Hm, I am not a mechanic or car specialist, but I finished technical school for electronics, and I reckon, you have a voltage/power issue - bad wire, bad battery, a bad connection from battery to the engine, as all those symptoms can be related to that from my experience.

Maybe someone had a similar or the same issue, I didn't and I have 2003. 2.5 z4 with 201.000 km on the clock.

2003 z4 2.5

Posted: Wed Jul 21, 2021 7:25 pm
by enuff_zed
Welcome to the forum, sorry it's in such circumstances.

I'm sure I won't be the last to say that before you do anything else, how old is the battery. They throw up all sorts of issues on these cars.

2003 z4 2.5

Posted: Wed Jul 21, 2021 7:58 pm
by Mr Tidy
Hi and welcome to the forum, although I'm sorry to hear your car is giving you such a hard time. :(

As suggested dying batteries on these can throw up all sorts of electrical issues - mine did when my battery died earlier this year.

If that isn't the problem you need to get the faults codes read via the OBD port and go from there, ideally by a good Independent BMW Specialist.

I could send you some matches, but I hope you can find a solution. :thumbsup:

2003 z4 2.5

Posted: Wed Jul 21, 2021 8:25 pm
by Ole gits rule
Battery is where I would start based on multiple electrical problems

2003 z4 2.5

Posted: Wed Jul 21, 2021 8:28 pm
by 1000rr
Unplug the MAF and see how you get on. :thumbsup:

2003 z4 2.5

Posted: Wed Jul 21, 2021 10:22 pm
by Gary busta Head
zriha, hi mileage is 90,000 was imported from Japan 3 years ago will try a new battery I even got the garage to remove all the carpets incase it had got wet at any point.

2003 z4 2.5

Posted: Wed Jul 21, 2021 10:30 pm
by Gary busta Head
enuff_zed, Mr Tidy, Hi mate I was in a Electrical specialist with all the latest gear sadly and codes were never the same twice, parts changed code cleared and then something else. I will try new battery this week . Tks

2003 z4 2.5

Posted: Wed Jul 21, 2021 10:34 pm
by Gary busta Head
enuff_zed, will try new battery ASAP know 1 mentioned that and I should of thought myself as the my Range Rover is run by the battery. Tks

2003 z4 2.5

Posted: Wed Jul 21, 2021 10:37 pm
by Gary busta Head
Ole gits rule, Thank you will get 1 this week a give it a try 😊

2003 z4 2.5

Posted: Wed Jul 21, 2021 10:39 pm
by Gary busta Head
1000rr, Hi and the MAF is what πŸ˜‚πŸ˜‚πŸ˜‚Tks

2003 z4 2.5

Posted: Wed Jul 21, 2021 11:15 pm
by Ole gits rule
Gary busta Head wrote: ↑Wed Jul 21, 2021 10:39 pm 1000rr, Hi and the MAF is what πŸ˜‚πŸ˜‚πŸ˜‚Tks
Mass air flow sensor - can cause issues with how the car runs - take a look on you tube for it :thumbsup:

2003 z4 2.5

Posted: Thu Jul 22, 2021 1:25 pm
by zriha
Also, if you can find in your local area a person with the same model of Z4, who is willing to give some parts for a try, like a Mass airflow sensor, or any other sensor, it is a cheap way to pinpoint the bad part.