Twin turbo difficult to start

Yep - these batteries degrade a few percent every year (no matter what your tester says) - it's physics.

After 5-7 years they are borderline, 10 years they are toast. If you had a >10 year old battery 'tested' somewhere & they said it was ok, you need to stop going to that place :)

They may seem to be ok & start the car, but the voltage they are putting out wreaks havoc with the voltage sensitive computers & sensors dotted around the car - and they run EVRYTHING.

It needs replacing regardless of other issues - but if you are lucky, this is the root cause.

Regards teh HPFP, there were 6 versions used in the e89 AFAIK, with the earliest being the most problematic (what you have). It got changed every couple of years to newer versions / software, but was never exactly perfect.
 
I’d definitely be looking at replacing the battery, there can be so many battery related problems that for the sake of £120 or so it’s not worth ignoring it. Possible misfire could be oil in the spark plugs wells.
 
eng622 said:
If it will start doesn't the alternator keep the voltage up to what is normal when running.
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You would think so but it doesn’t, the system is very sensitive to slight variations in voltage and current.
 
eng622 said:
If it will start doesn't the alternator keep the voltage up to what is normal when running.
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No because the alternator does not decide when and how to charge the battery..that rests with the engine’s ECU and the intelligent battery sensor,,a duff battery throws a major spanner in the works..

These cars are incredibly complex electrically so without a full understanding of the architecture and the subsystems you are floundering in the dark…hand it over to a professional :thumbsup:
 
In this case - with this user - I'm inclined to agree with B21.

Take it to an expert.

DIY & forum guidance only works if the recipient is able to undertake the steps described, not everyone has tools / knowledge / skills in this area.

We have some facts that are not up for debate:

(i) Decent code reader that understands BMW specific issues is needed if you want to DIY the e89
(ii) Batteries degrade over time - the e89 is super sensitive to that & any issue that needs electricity could be battery related

I've lost count over the years how many posts on here have appeared unrelated (coses thrown for windows / boot / lights / cluster / engine) that ahve been eventually fixed by changing the battery. Usually after half a dozen other things have been tried.
 
Looks like I have made a few mistakes with my battery as assume it is an AGM type. Do not use the car for 4 months over the winter and charge it once a month but with a standard charger across the battery terminals, which I read is the wrong method. Never had any problems until now. The terminal voltage is 12.2 V lower than a lead acid at say 12.6 but has always been like that. The only malfunction in the past has been on starting where an image of a car jacked up of the ground appears sometimes appears and the clock trips with no display. Not done this for some time though.
Should I be buying another AGM or any 096 type.
Understand a new battery needs to be registered and coded to the car computer. Can any competent mechanic/garage do this as do not want to take to the likes of Sytner.
Hoping to get to Sytner to have the recall battery done first.
 
eng622 said:
Looks like I have made a few mistakes with my battery as assume it is an AGM type. Do not use the car for 4 months over the winter and charge it once a month but with a standard charger across the battery terminals, which I read is the wrong method. Never had any problems until now. The terminal voltage is 12.2 V lower than a lead acid at say 12.6 but has always been like that. The only malfunction in the past has been on starting where an image of a car jacked up of the ground appears sometimes appears and the clock trips with no display. Not done this for some time though.
Should I be buying another AGM or any 096 type.
Understand a new battery needs to be registered and coded to the car computer. Can any competent mechanic/garage do this as do not want to take to the likes of Sytner.
Hoping to get to Sytner to have the recall battery done first.
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AGM just means 'Absorbent Glass Mat'. ALL car batteries (unless Li-ion) are lead acid. AGM are standard on pretty much all modern BMWs. AGM is just a way of getting more 'juice' into a given space.

Personally I wouldn't let Shytners clean my windows, let alone touch my car, but that is a different matter. The E89 needs a new battery coding because of the IBS (not Irritable Bowel Syndrome but Intelligent Battery Sensor).
 
If you fit the same amperage battery then it only needs registering to the car so that it knows it’s a new one, most garages should be able to do this with their scanner, it’s not critical to have this done immediately but better sooner rather than later, it’s not difficult to change the battery yourself so either order a new AGM one online or call into a local motorist shop ASAP and get it changed 😁
 
You might be super lucky, the battery reading 12.2v means it is fooked.

Could it be all that's wrong? It could be.

Absolutely needs to be changed before doing anything else.
 
Batteries are an absolute pain on the Z4, mine went the day I was due to collect it, it caused the old handbrake waring light issue.

The car had to go to BMW for a new battery and software update - cost the garage I bought it from around £500 to get sorted
 
OK hoping to get the car to Sytner for the recall battery cable and they have offered a free health check. So that might reveal if the battery is US. Will change anyway with an AGM one with same AH and CCA. Read only needs to be registered and not coded so going to the mechanic who did the scan to fit the battery and register it. I'm getting on in years and don't think I would be able to lift the battery out and in.
Interesting to see if Sytner come up with anything else.
 
Given what you have said so far, the healthcheck is going to give you a list as long as your arm.

2 pinches of salt required.

A 13 year old z4.... being assessed by Sytner?

Brace yourself Sidney!
 
Some good news as passed the MOT today. EML light was off, which needs to be on 2007 and newer so I am told. The half light was on. The tester, the mechanic who did the OBD scan, commented on how low the emissions were. CO 0.002, HC 20, Lambda 1.002. He thinks the problem is a fuel blockage. Anyway of to Sytner tomorrow all being well.
 
Hard work starting at least 8 goes but got to Sytners. Drove back ok with EML on and half light. Switched off and then trouble restarting and when it did it would not idle, kept stalling. The low battery light then came on so now charging. No proof that Sytners have replaced the cable all they gave me was a health check sheet noting EML on and rattle from the engine bay. This rattle always occurs when the half light comes on. So change the battery next.
Sytner sent a video by phone checking the underside and did a full valet all FOC so cannot knock them for that. But no sign of any disturbance in the boot, dirt in it undisturbed. Anyone know anything about this cable I take it to run from the battery to the fuse box but no idea where it is routed.
 
eng622 said:
Professional scanner codes results
0029F2 - high pressure fuel system
002FBF - fuel pressure on release of injection
Also a code on low battery voltage which was not thought relevant but maybe it is. I'm thinking the problem may well be electrical.
This is what happened next. Codes were erased but while idling the EML came on and when I drove off the half eng light. Mechanic started the car and did note it took several cranks to start Only 1/4 mile back home. Switched off and restarted. EML on and quickly the half light came on and the engine went into very rough idle backfired in the exhaust badly on revving up and then would not idle just stalled. Tried numerous times and would not idle for more than a few seconds. So looks as if it will not go anywhere as DCT.
So plugged in my scanner and got 3 new codes saying random/multiple misfire and misfire on cyl 3 & 4. Not surprised by this result as car looks like it will not drive anywhere.
Now I erased the codes and the car started quickly idled at 700 rpm and very smooth. Revved up gently to 1500 rpm and no lights came on but did not road test as worried about stalling.
I'm reading that the misfires were due to lack of fuel and it is the HPFP that is not delivering correct amount but may not be the pump.
Mechanic said first to check the fuel filter but these are said to be for life (car only done 40K miles) and with the pump/filter in the tank a difficult job.
So think should measure LPFP pressure.
The fault does look intermittent and could be electrical. Where is the pump connector located.
Also could be the positive battery terminal lead which is a recall, not done but booked in for Thursday if I can get the car there.
T
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Usually those codes are HPFP failing …FWIW
 
HPFP is mechanical pump, but has an electric solenoid. Would not expect a mechanical device to be intermittent.
Thinking it is electrical, this is why.
Yesterday said on return from Sytner would not idle and kept stalling. So charged the battery for 8 hours, charger said fully charged and 12.5 V which is low, should be ~ 12.8. Today late afternoon only 12.08V. Started with long crank, erratic idle for a few seconds and then smooth, revved up no warning lights. Switched off and now 12.4V. Restarted instantly no hesitation and no lights. Switched off now 12.45V. But on both starts the battery voltage fell after a few minutes to 12.3V. I think this is telling me the battery is US.
The LPFP is electric and feeds the HPFP and the battery can be a problem from what I read on here.
 
eng622 said:
HPFP is mechanical pump, but has an electric solenoid. Would not expect a mechanical device to be intermittent.
Thinking it is electrical, this is why.
Yesterday said on return from Sytner would not idle and kept stalling. So charged the battery for 8 hours, charger said fully charged and 12.5 V which is low, should be ~ 12.8. Today late afternoon only 12.08V. Started with long crank, erratic idle for a few seconds and then smooth, revved up no warning lights. Switched off and now 12.4V. Restarted instantly no hesitation and no lights. Switched off now 12.45V. But on both starts the battery voltage fell after a few minutes to 12.3V. I think this is telling me the battery is US.
The LPFP is electric and feeds the HPFP and the battery can be a problem from what I read on here.
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I assume you had replaced the 2009 battery as a matter of course..

The LPFP runs satisfactorily to quite low bus voltages..
 
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