2003 TDI Auto Still stopping intermittently!!

[bigjeeze]

Hi Guys,

This fault is driving me nuts! It's just cost me Ã,£15K!!! ( I had to buy the Mrs a new car!!!)  When working correctly everything is fine, but on the odd occasion with no warning the engine just stops. It sometimes starts almost straight away but can also turn over and not start so that the battery runs flat.  I have removed and checked the pump in the fuel tank - No blockages and appears to be running OK. I have replaced relay 109 twice now and still the fault appears.   Any ideas? Where to look - I have no ideas left!.

BJ

[johnnyroper]

Have you ever changed the crank sensor?

[brianh]

When working correctly everything is fine, but on the odd occasion with no warning the engine just stops. It sometimes starts almost straight away but can also turn over and not start so that the battery runs flat.

When its refusing to start, can you get the diagnostics to speak to it at that point? When i had this issue with both my mk1 and mk2 (though both were petrols) they would not speak to the diagnostics at the same point where they wouldn't start. I would suspect this is down to the immobiliser not being deactivated (IE your typical relay 30/109 issues).

If it doesn't want to connect in that state, its something on that circuit causing a problem, either a bad connection somewhere (Relay contacts in the fusebox, fuse holder, any of the wiring between). From memory the ecu for the immobiliser is accessible from the footwell (you can follow the wires from the coil round the ignition barrel to the ecu) is that properly seated into the socket?

If it does connect, but fails to start its doubtful that its the immobiliser - the door led should give some clues if it is that, as it tends to flash rapidly if there is an issue with it.

[bigjeeze]

No Johnny I haven't changed the crank sensor.  I am not sure such a random intermittent fault would be caused by the crank sensor. It feels like a fuel issue possibly caused by something electrical.

[bigjeeze]

Thanks Brian,

I am wondering whether it is an immobiliser issue - but if so again, why the random nature.  On a previous occasion when the car stopped it was on a roundabout - I managed to get it off the roundabout and pulled in to a verge on the left whereby the car was tilted to the right, and when i tried to restart it fired immediately.  Now that may be a pure coincidence but it seems more fuel based to me.  Any ideas on that score?

BJ

[brianh]

I know my MK2 would randomly cut out when the solder joints went - I had it a couple of times heading up the A34 where it would stutter, then carry on just fine. It then decided to stop on the M40 after that, and would not restart, got out to have a look at the fusebox under the bonnet, closed the bonnet, closed the door (probabbly a bit harder than I usually would), pulled phone out to try and get hold of RAC, whilst waiting for them to answer tried starting it again and it fired up. Had much the same happen on the A3, the only pattern I'd noticed was it would only ever do it after it had been running a while - typically about 60 miles so would suspect its a heat related thing. Resoldered the relay joints (which had clearly gone dry when i pulled the relay out as you could see a gap on them) and it stopped the cutting out issue and no more starting issues. only noticable difference is the starter on mine didn't crank, but given its a petrol that may be just the way they are.

I didn't think it would be immobiliser/relay related given the mk1 when i had problems with the relay, never cut out once it was started. The mk2 on the other hand does. I did initially blame the hardwire kit for the dashcam which I'd put on the bottom righthand fuse - which I later found out to be the power supply to the ecu as if you pull it with the engine running it will cut out - you don't have anything extra on that fuse do you (its one of the few I could get the fuse holder onto which was ignition switched hence why I'd used it)

Either way, if you can find a cheap obd scanner you can keep in the car, and try scanning when it plays up, that might give you an answer - if it won't talk you know its some sort of immobiliser issue, if it will then its looking like something else is the cause. The door LED might be enough to tell you if it works as well?

[johnnyroper]

Immobiliser could explain the non start but I wouldnââ,¬â,,¢t think it would cause the cutting out as once started the immobiliser has no bearing on it. Relay issue could as it would kill power to ECU giving symptoms of immobiliser fault.
As above a code reader ideally with live data could be the key as it will show any parameters out of spec when car does play up assuming it connects to ECU. A failed crank sensor does not always show a fault but would stop fuelling Similar to what you describe. Not sure a cam sensor on a PD does that usually they cause difficult hot starting when failing again not always giving a code.

[mike wilson]

A long time ago, in a galaxy far away 8 -) this was caused by the cardboard inner off the inside of an additive bottle top being loose in the tank and occasionally blocking the fuel outlet.  Might be worth investigating.

[bigjeeze]

I have just swapped the fuel pump form my other galaxy to this one and will see what transpires. I had as good a look as I could in the tank without being able to remove it and I could not see any floating detritus or otherwise.

I'll let you know how it progresses.

BJ

[bigjeeze]

Well so far so good. I'll keep you in the loop!

[bigjeeze]

Just a brief note. I have been using the Galaxy and all has been well until this morning. It stopped again!  So it wasn't/isn't the pump!.

[brianh]

Have a prod around with the crank sensor - Not on the Galaxy, but I've had one that gave me grief on a Focus for months until I found what it was (when it failed completely pulling out of a petrol station leaving me stuck in the middle of the road and refusing to start). Might be a bad connection or a dodgy sensor, but that might help narrow it down.

[bigjeeze]

Thanks Brian - will do.  On the way home last night ( a short 2 mile journey) the warning Engine Garage! came up and the glow plug light was flashing.   Stopped and restarted and it went away. It was fine this morning but again on the way home the same thing. Stopped and started and all well again!

[brianh]

I think the flashing glow plug light is usually down to the brake pedal switch?

Either way, if its done that, I'd expect a code read should be telling you why now? Though of course it may be something else entirely!

[insanitybeard]

Not really the same set of symptoms but I previously had intermittent problems trying to start my 130 TDI, especially on a part warm engine. Sometimes it would be a complete pig to restart. Eventually it logged an intermittent signal fault code for the camshaft position sensor, and replacement of said sensor rectified the issue. Prior to this I tried replacing relay 53 and relay 109 with no effect. Also I believe there have been some tales of them drawing air in where the plastic tee goes into the top of the fuel filter causing fuel starvation? Can't speak from experience on that one but I did renew the O-rings on this tee (which helpfully aren't supplied with the new fuel filter ) when I renewed the fuel filter to hopefully prevent this ever being a problem.

[bigjeeze]

Thanks for this.

I haven't previously heard that relay 53 could be responsible. I'll try that and a new cam sensor. It's become a real issue lately - it happens virtually every day. If it fails the MOT next week on anything remotely expensive or difficult then it's of to the scrapyard!!.

Regards

BJ

[insanitybeard]

Relay 53 is quite possibly a red herring, I tried replacing it because I thought it may have had a bearing on the fault I had but in the end that wasn't the cause. If you've not read it, my original symptoms were described in the below thread along with some other comments by people who also had issues with starting:

https://www.fordmpv.com/smf2/ford-galaxy-vw-sharan-seat-alhambra/intermittent-starting-problem

[bigjeeze]

Had a quick look and the relay looks OK and can hear it operating on and off. I'll get a new one anyway. Cam Position sensor - I have one in stock - but it looks like I have to remove the cam belt etc to get it out. Is this the case or is there a way to do it without removing the whole shebang?

Also have a Crank position sensor - where exactly is that located and is is replaceable without major dismantling?

Cheers

BJ

[brianh]

It should be number 5 on this link
https://volkswagen.7zap.com/en/rdw/sharan+syncro+4motion/sha/2003-406/1/103-103020/

I've only ever dealt with them on Ford petrol engines, but on those the most tricky thing after finding them is getting the connector and single bolt out of them, if you've got a selection of tools to fit whatever holds it in place (might be a torx bolt rather than standard hex) then its doable without major dismantling. I've done them on the side of the road with a couple of sockets and a ratchet from the top of the car, but not on the Galaxy specifically.

It should be close to the flywheel as it uses the flywheel for the detection of the pulses, at the front side of the car, close to where the gearbox joins the engine.

Note that its magnetic, so might be covered in crap and if your lucky might respond to a clean up if your lucky.

[johnnyroper]

The cam sensor is doable without removing the belt there is a rubber bung in rear cover you remove to allow plug to fit through. Put some rag under sensor just in case you drop the bolt. A bit fiddly but it can be done with everything in place.

If I remember correctly crank sensor is fairly simple on a PD itââ,¬â,,¢s in front of the block between oil filter housing and bell housing. On earlier PD anyway if itââ,¬â,,¢s a later type it could be through an access hole at end of block measuring feedback from tone wheel on rear main oil seal.

[bigjeeze]

Thanks Guys, I'll give it a try.

BJ

[insanitybeard]

There are a few pics and notes regarding camshaft position sensor replacement in the below thread which may be helpful:

https://www.fordmpv.com/smf2/ford-galaxy-vw-sharan-seat-alhambra/help-pls-vcds-has-picked-a-few-faults-before-it-stopped-working/msg19901/#msg19901