Not feeling much love at the moment for Z4

step_change

Active member
 Planet Earth
Car has been as good as gold and taken me all over the country and is a DD for me. I also have a 640D but like the Z4.

Wednesday morning, started the car (started and ran fine initially) and drove off. Cold morning and car had been out on the drive in the cold and not driven for a few days. Normally it is garaged but moving house so a ton of stuff in garage.
One mile from home on busy A52 cough, splutter, misfire whilst driving and then stalled at the lights. Could not get it going again. I was blocking the road. So turned off ignition tried to start engine again. Dead and lit up like a xmas tree and even starter motor would not turn. Tried this six or so more times. Eventually started, it then drove OK, a bit of stuttering but with engine warning light on. I got it back home.
Did something similar earlier in June and was a split air hose. Repaired that myself and fixed it. Not this time, visually all OK.

Took it to Indy today, very reputable and I have used him before and it started up fine this morning. No problems at all and drove fine but with engine warning light on. Indy diagnosed Cam Shaft sensor not in sync with crankshaft sensor from the code and changed it. Warning light is now gone and road tested fine. Will collect it on Monday and a £150 repair. However he said that, unlikely, there are other things that could cause that code and he changed the most common and cheapest first. Let's hope this has fixed it. Other things it could be is VANOS solenoids or timing belt, both much more expensive to fix though he said he would not expect that at 48000 miles on the 2.5.

Whilst there I asked him to look why, on the M25 two months ago, my ABS (and several other) warning lights came on. The fault cleared itself when I stopped at Warwick services and has not come back on since. He said the warning code is an ABS pump and it is a very expensive repair - £2000 from BMW for the part alone - or can be rebuilt for about £400-£600. But he said leave it for now and see if it comes back.

So not feeling much love for the car at the minute!
 
Unpicking your symptoms, "Starter motor would not turn": Whilst accepting you might have multiple problems the starter not turning cannot be down to cam sensors or ABS (or any sensor for that matter). I'd go with either the common ignition key switch fault which most people report being intermittent, or battery/alternator or earthing and lastly the starter. Either the key switch or a battery/alternator/earthing failure can cause multiple fault lights and should be eliminated before shelling out on other repairs.
 
Thanks Ewazix, ... since the car is an auto I might have been in a panic whilst blocking the busy A52 (main route into Nottingham!) and still had the car in gear hence not allowing me to remove the key in the ignition. Maybe I am incorrect with the start motor thingy.
 
A lot of those symptoms sound like a dodgy alternator causing power spikes & dips.

Mine did a similar thing this Monday at 6am on the M6, which resulted in me having no power (i.e. no engine power or lighting). Luckily I was going quick enough that I could use my momentum to move from lane 4 to the hard shoulder without causing any avoiding actions from those around me (despite having no lights/indicators).

I had almost every light up on the dash and the error codes recorded included MAF, TPS, ABS, O2, steering angle, etc.

£400 later (new alternator that BMW want £800 for) and I have a new alternator and all the lights have been reset and have not come back.
 
Thanks. In this case the two faults have persisted. Maybe there could be a few simultaneous issues I have with it.
 
step_change said:
Thanks Ewazix, ... since the car is an auto I might have been in a panic whilst blocking the busy A52 (main route into Nottingham!) and still had the car in gear hence not allowing me to remove the key in the ignition. Maybe I am incorrect with the start motor thingy.

I can see how that could happen, in which case I'd definitely have the battery, charging system and earths checked and eliminated before sploshing the dosh on other repairs, it could be many things but battery, charging or earths are the most obvious to start with.
 
I would be changing your garage to one that knows the 2.5 doesn't have a timing belt!

Did you get a copy of the codes? Ignition switch could possibly be the culprit, and a power on reset code being stored could indicate this. What were the abs codes?

Mike
 
Ducklakeview said:
I would be changing your garage to one that knows the 2.5 doesn't have a timing belt!

Did you get a copy of the codes? Ignition switch could possibly be the culprit, and a power on reset code being stored could indicate this. What were the abs codes?

Mike

Timing belt night not have been the exact phrase Mike. But it was something like that....
 
I had similar issues at least with random warnings popping up when my battery was on its last legs, new battery fixed em all instantly
 
85genius said:
I had similar issues at least with random warnings popping up when my battery was on its last legs, new battery fixed em all instantly

Spec me a decent battery then guys. I was thinking of swapping it out anyway in January but might as well do so now.

Kwik-Fit is looking at £100 which I think seems steep....
 
step_change said:
85genius said:
I had similar issues at least with random warnings popping up when my battery was on its last legs, new battery fixed em all instantly

Spec me a decent battery then guys. I was thinking of swapping it out anyway in January but might as well do so now.

Kwik-Fit is looking at £100 which I think seems steep....

Good prices here; https://www.tayna.co.uk

Costco also good for Bosch if you have a card?

However, I would be testing the battery properly first, before simply replacing it - If you are about I can do it for you in a couple of mins.

Mike
 
Scooba_Steve said:
Try the £10 new ignition switch first :)

Agreed, if it is a tenner it is a good part to eliminate. However, I'm not having much luck finding an ignition switch in UK for a tenner (seen them for £40). Plenty on eBay but from China and that kinda puts me off. I do not want to replace with a dodgy "new" one.....


Still want to get a cable of you Steve btw, is this still on from you? Been away with work.
 
Ducklakeview said:
step_change said:
85genius said:
I had similar issues at least with random warnings popping up when my battery was on its last legs, new battery fixed em all instantly

Spec me a decent battery then guys. I was thinking of swapping it out anyway in January but might as well do so now.

Kwik-Fit is looking at £100 which I think seems steep....

Good prices here; https://www.tayna.co.uk

Costco also good for Bosch if you have a card?

However, I would be testing the battery properly first, before simply replacing it - If you are about I can do it for you in a couple of mins.

Mike
I've got my last few batteries from Tanya top service and prices! Always bought from their eBay store never bothered to look if they had a website..

This is what I'm running now


https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.co.uk%2Fulk%2Fitm%2F251410202004
 
Got the car back with the cam sensor change and it feels like a new car, much more growl midrange. Done 200 miles in separate 10 mile journeys and not missed a beat. Hopefully this was the issue that led to the above.

I have tested the battery the best I can (without a drop charge tester, just a DVM) and it seems OK. Might be worth swapping the ignition switch out though still......
 
step_change said:
Got the car back with the cam sensor change and it feels like a new car, much more growl midrange. Done 200 miles in separate 10 mile journeys and not missed a beat. Hopefully this was the issue that led to the above.

I have tested the battery the best I can (without a drop charge tester, just a DVM) and it seems OK. Might be worth swapping the ignition switch out though still......

Great news - nothing more disheartening than having mystery issues with a long list of ever more expensive replacement parts to eliminate in order to reach the solution!
 
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