Z3 Starter wont turn properly

[Tim]

Recommissioning a Z3 roadster automatic - 4 cylinder, P reg

Its been standing since 2010 without a battery, so knew it would take some effort to get it started!

New battery fitted, remote 2 button key operates central locking etc fine and all expected lights operate ok. Minimum amount of alloy cover oxidisation in the engine bay shows that it has been kept nice and dry.

Operate starter - starter kicks but doesn't turn the engine over. Jump start with another battery connected with heavy leads to earth direct on engine mount bracket and positive terminal in engine bay in case there is any earth strap corrosion problems. Same behaviour.

Take spark plugs out to remove compression load, and turn the engine over fine with a spanner on the bottom crank pulley. Try starter again with no load. It kicks (cooling fan just starts turning) and then starter motor stops.

Checked volts at engine under starter load and they sink slightly as starter tries and then rise as it apparently gets disconnected. The motion of the starter motor suggests that this is not jammed.

Is this an immobiliser problem stopping the starter? Does it disable the starter solenoid but not immediately?

Normally I would have expected the behaviour to either have no starter activity at all, or starter spins but ignition is shut off if the immobiliser was active.

I have checked previous posts, and normally these are related to erratic restart problems.

I have an OBD port diagnostic - I believe that Z3's have an in cabin 16 pin OBD port as well as the under bonnet 20 pin connector. is this right? Probably far too early to worry about the niceties of error codes!

 

[GazHyde]

Welcome Tim!

Seems similar to a recent thread here... http://zroadster.org/threads/z3-1-9l-engine-now-installed-but-wont-start.4733/

I'm not mechanical so can't help but perhaps someone from the [USERGROUP=12][USERGROUP=12]@M44 Massive[/USERGROUP][/USERGROUP] will be along soon to offer guidance.

Gary

 

[t-tony]

Welcome Tim,where you at? As Gaz says the m44 specialists will come out of the pub/woodwork etc soon and then you will have a mine of info. I'm not much use at the moment still on Florida time, just got home. I'll be back later.

 

[zedonist]

Still dreaming of the pub!

It's my understanding the immobiliser prevents the starter working all together. Have you removed the starter and tried it off the car does it throw out the starting ring?

Sluggish starters are normally low voltage, knackered battery / alternator or bad earths or the starter is k put.

The only diagnostic port that works on the Z3 is the old round 20 pin under the bonnet, I would put the diagnostics on, as it will record codes for a non start especially caused by a sensor or the alarm etc.

 

[zedonist]

Mice also jumps to mind as it has stood for 4 years, you may have some nibbled cables.

 

[vintage42]

... The only diagnostic port that works on the Z3 is the old round 20 pin under the bonnet, I would put the diagnostics on, as it will record codes for a non start especially caused by a sensor or the alarm etc.

My 1997 (10/96) M44 has the round port under the hood. I use that port for resetting the oil change interval with a cheap tool.
http://i49.photobucket.com/albums/f280/vintagefortytwo/BMW Z3 Related/SvcResetToolforBMW.jpg
It also has a rectangular port on the side of the console. I use that for a ScanGauge that displays engine functions and error codes.
http://i49.photobucket.com/albums/f280/vintagefortytwo/BMW Z3 Related/ScanGauge/ScanGaugeampiPhone_zpsfcc71d04.jpg
http://i49.photobucket.com/albums/f280/vintagefortytwo/BMW Z3 Related/ScanGauge/ScanGaugeOn_zps0ee4d6bf.jpg

 

[Tim]

Thanks - will try the OBD and see what codes are recorded. If nit it will have to be the 20pin - strange sine the eBay cables seem to be 20-pin to the OBD to USB box I already have.

The starter problem is strange as it seems to try. That's why I put jump leads from a second battery direct onto the the engine mounting to check and see if it was an earth strap corrosion problem. Seem to be getting a reasonable load voltage at the engine when I checked with a meter. When I checked through the previous posts the normal oroblem seems to be an intermittent key, and Z3s don't seem to be sensitive to long term battery disconnect.

I wondered if it was some strange BMW Z3 known immobiliser behaviour before I took the starter motor out. I now remember why I don't like automatics!

 

[t-tony]

Try putting a jump lead between a good earth point on the engine block and a good ground point on the chassis and try the starter again. This eliminates a poor earth from battery to ground. Had this happen on my VW Touareg last winter. Made and fitted a new lead from the engine block to the cassis - no more problem. This car was stood all through last summer, prior to the it gave no indication of any fault at all.

 

[Tim]

Thanks - tried the earth bonding one, I have a Mini Cooper and earth bonding is the normal source of all electrical problems! The problem behaviour is very close to this.

One other thing I have noticed, which I dont know is normal is a buzzing noise from the throttle body that continues for about 30 seconds when key is turned. I am assuming this is a stepper motoron a flap valve, but it does seem to be a longtime to take for a quick cold start.

Going to look and see whatlogged faults are available from the OBD

 

[zedonist]

My 1997 (10/96) M44 has the round port under the hood. I use that port for resetting the oil change interval with a cheap tool.
http://i49.photobucket.com/albums/f280/vintagefortytwo/BMW Z3 Related/SvcResetToolforBMW.jpg
It also has a rectangular port on the side of the console. I use that for a ScanGauge that displays engine functions and error codes.
http://i49.photobucket.com/albums/f280/vintagefortytwo/BMW Z3 Related/ScanGauge/ScanGaugeampiPhone_zpsfcc71d04.jpg
http://i49.photobucket.com/albums/f280/vintagefortytwo/BMW Z3 Related/ScanGauge/ScanGaugeOn_zps0ee4d6bf.jpg

Eurpean cars don't have the secondary OBD2 ports where you have yours, diagnostics are done through the 20 pin under bonnet OBD port.

 

[zedonist]

Thanks - tried the earth bonding one, I have a Mini Cooper and earth bonding is the normal source of all electrical problems! The problem behaviour is very close to this.

One other thing I have noticed, which I dont know is normal is a buzzing noise from the throttle body that continues for about 30 seconds when key is turned. I am assuming this is a stepper motoron a flap valve, but it does seem to be a longtime to take for a quick cold start.

Going to look and see whatlogged faults are available from the OBD

Tim if you have an ipad there is an app called "fault codes" just select BMW and type the code in it will tell you the likely root causes for the codes.

 

[Tim]

Cant find any OBD socket in the cabin. The sides of the console are smooth with no hatch. Cant find anything in the centre console either, so that is consistent! Dont have Apple - only Android or Windows - I have a selection of diagnostic software for OBD on a Windows laptop with an ELM based interface cable. Works well and connects to all the OBD standards I have tried it with. But then you have to have an OBD port......

Think I have found the 20 pin socket on the drivers side in the engine bay.

Any experience with the 20 pin to OBD adapter cables like this?

http://www.ebay.co.uk/itm/New-20-Pi...UK_Measuring_Tools_Levels&hash=item43c7634b89

If so looks like a cheap way to get access.

 

[GazHyde]

This thread may help with the cables

http://zroadster.org/threads/wifi-diagnostics.4619

 

[zedonist]

Cant find any OBD socket in the cabin. The sides of the console are smooth with no hatch. Cant find anything in the centre console either, so that is consistent! Dont have Apple - only Android or Windows - I have a selection of diagnostic software for OBD on a Windows laptop with an ELM based interface cable. Works well and connects to all the OBD standards I have tried it with. But then you have to have an OBD port......

Think I have found the 20 pin socket on the drivers side in the engine bay.

Any experience with the 20 pin to OBD adapter cables like this?

http://www.ebay.co.uk/itm/New-20-Pi...UK_Measuring_Tools_Levels&hash=item43c7634b89

If so looks like a cheap way to get access.

Tim, the only diagnostic port that works on the Z3 is the 20 pin under the bonnet on the driver side, as you have found, the cable you have inked to on ebay, should allow you to attach your ELM device, it is the same as we are using with our ELM devices to IPAD.

 

[lmrdave]

If the starter is spinning, but not turning the engine, it's a more than likely change the solenoid that engages the starter gear on the the fly wheel is not working or siezed due to being stood. Sometimes you can 'tap' the solenoid part to free ir, or remove and clean, or it might be a new starter motor, although second hand units are pretty cheap. You'll also need an external torx spanner to get it off (if it's anything like the 2.8 version), DON NOT round these off, especially the hardest one to get to, been there done that!

 

[jpr1977]

Tim

Having recently re-commisioned a 2.8 after 7yrs slumber i know how frustrating things like this are...(have a look at some of my previous posts). It does sound very similar to the issues I was having and would definatley reccomend try runing a -ve jumper cable from the starter body to the under bonnet connection/known good earth, as t-tony mentioned, to rule out any earth issues, as this flagged the problem for me. I similary went down the line of jumper battery with very similar results to yourself, which led me to believe imobiliser issues and wasted a lot of time... ( I eventually found that after a second round of earth cleaning the car started fine and has done ever since, even after 3-4 weeks in a garage, i'd particularly focus on the main engine/body connection,which i think was the crux for me)

If the same still occurs try the sticking solanoid trick as above or if possible a new starter, recently had a mk1 golf that wouldn't start due to a lazy starter, new one solved the problem instantly, though these are a 2min job in a golf, which i'm sure isn't the case on an auto...

Where are you as i'm sure someone near will be able to provide/lend a 20pin plug (though if it's anything like the 2.8, it'll be blank which is good overall but very frustrating trying to diagnose non-starting...)

PM me if you need anything as i went round in many many circles before i resolved the problem...

Jp

 

[Tim]

Went through the earth bond and connected a 2nd good battery via heavy leads to the under bonnet jump point and earthed direct to the engine block.- result was the same, starter just kicked the engine.
Same behaviour with plugs out and no compression so light starting load.

Bought the 20 pin OBD plug and checked that no faults logged.

Looked through the forum at immobiliser faults and saw that keys have a bit of a reputation for going intermittent. Got hold of the spare key for the car. Result was that the starter turned properly and the engine started straight away!

Very surprised (and pleased!). I would have thought that the starter would have been totally disabled, not just kicking enough for the cooling fan to spin for about a revolution before shutting down.

Runs and idles fine - as long as the spare key is used (consistently bad!)

How many Z3s still have the spare key? I think I was lucky....

Appreciate all the help with this.

 

[FRANKIE]

This was taken from a Honda manual for a 1994 Honda Del Sol. It has several steps listed for testing the starter in the vehicle. Step 11 tells you what voltage to look for:

The following was taken from the Haynes BMW manual: