Cold start issues leading to non starter

[Sprech]

On any given morning, worst if cold, but generally always bad: First time I insert the key, wait for lights to come off, press it in, the very first rev of the engine is sloooow (DSG in parked position). As if it something gooey is being loosened. Like arthritis pain just after getting out of bed, and feeling ok after a moving around for a few seconds. Subsequent revs go fine. The engine will not power on the first attempt, but nearly always on the second attempt.

Eventually it wouldn't start at all, even with 3-4-5 attempts. Had it fixed by a reputable VW Audi specialist garage. It would then start on first attempt. After a few months the problem is back, I need two start attempts to get it going, and this week, it's not starting at all.

They have so far changed the glow plugs, the engine speed sensor, and battery. Taking it back this week. Keen to hear if anyone can suggest what might be wrong. I'm interested in theories around the first difficult rev when the engine has been still over night.

Car: VW PASSAT SE TDI 140 AUTO 2007 (07 reg)

[RichardSEL]

There may be something showing up in stored faults. Get yourself a VCDS Autoscan and see what's being reported?

I'm in SE London, by Sun in the Sands roundabout off the A102 southbound out of Blackwall Tunnel. Otherwise there's users here who might do a scan for beer tokens:
https://maps.google.co.uk/maps/ms?msid=209563024277134815192.0004c505be14b22419db e&msa=0&ll=56.231139,-2.779541&spn=3.493691,10.821533&iwloc=0004c505cfcb6158e0447

What did the "reputable VW Audi (http://www.tesco.com/direct/-/682-4910.prd) specialist garage" do? When? How many miles ago?

[Sprech]

Probably no more than 1500 miles done since the last time it was in for this symptom. They charged £400 to replace the speed sensor as apparently it somewhat inaccessible. They also did the glow plugs earlier last year, as the warning light came on in the dash board.

What kit will I need to use this VCDS Autoscan, how much do you think it will cost me?

I guess this one: Ross-Tech: Micro-CAN Interface (http://www.ross-tech.com/vag-com/Micro-CAN.html) but it's $249. Is the software free?

[RichardSEL]

Those repairs seem not to have cured the faults you went to them for

If you want to buy your own Vag-Com cheapest in UK for your car is Micro-Can available from Gendan over here. Yes, the software auto-downloads and auto-updates to registered users lifetime for free. One year tech support and one year (but now extended) user support. Own private forum and own public forum.

Or I can Autoscan for you a tenner -- if you come to me, or +petrol if I come to you. Where are you?

[Sprech]

I'm in Streatham Vale. The car is being towed tonight anyway.

I've seen a thread suggesting the symptom could be related to the fuel filter, I think it was you even. Could it be?

[martin1810]

I suggest you get the glowplugs checked. garages often fit the wrong ones.
VCDS will show the start procedure which can be checked for errors.

[RichardSEL]

>> I'm in Streatham Vale. The car is being towed tonight anyway.
>> I've seen a thread suggesting the symptom could be related to the fuel filter (http://shop.ebay.co.uk/?_nkw=fuel+filter), I think it was you even. Could it be?

Fuel filter usually shows itself as a start then stop coz the gunk slowly does allow fuel to get thru but the gunk then stops sufficient flow
Streatham Vale's not too far

You have PM

[Sprech]

There's an old trafficmaster satnav in the car. I removed the thing from the dash and cut the wire... There's still something left. I've no idea what.

The garage thinks it might drain the battery. I'm thinking maybe, but enough to cause a slowly emerging pattern of starting problems.

The thing is, they said it takes 20-30 minutes JUST to rig up a drain test, and then it takes an hour or two to complete. Can this be true?

[martin1810]

It takes minutes to set up a drain test and minutes to get a result as long as you have a decent meter and know what to do.

[Sprech]

That was my understanding as well. Thanks for confirming.

[Sprech]

Found a video. This is *exactly* what's happening. I would add the cranking speed on mine appears to be even slower than in the video below. I will ask the garage for a starter motor replacement.

VW Passat B6 2005 2.0 TDi 140PS No Start Condition - YouTube (https://m.youtube.com/watch?v=Ef8KdLHzgzY)

Q: So if the starter motor is not going as fast as it should, could this explain why they found a fault with the engine speed sensor, with their diagnostics tool?
Q: How much should it cost to replace the starter motor - parts and labour?

[RichardSEL]

For goodness sake. Stop guessing. Start diagnosing! A VCDS Autoscan will show a drained battery condition by reason of its "Terminal B"
voltage readings taken at the time faults occur

Those are ridiculous times to check for a "drain test". Main agent (or VAG indie with VAS) will be doing a VAS diagnosis first (like a VCDS Autoscan) which they charge an hour for (it takes max ½ hour) And then will connect up the equivalent of an ammeter in series with the battery + lead to see what current's being taken when car enters sleep mode (shut down and locked up, no lights on, no one inside)

[Sprech]

I hear you. Would you attach the VCDS immediately after the first failed attempt of cranking?

[RichardSEL]

No, I attach VCDS on arrival. Perform an Autoscan and with that report see what each module is reporting. Then clear all faults in each module. So then you have a record of what's been reported in the past.
Next stage is to try start car. If there's very low crank speed or difficulty in starting then take another Autoscan and see what's happened at that time. If there's reports of "Terminal B" voltage or volts being reported as low (bear in mind unlike cars of old these electronic-controlled cars are very sensitive to battery volts) take it from there.

I wouldn't speculate until you have this info -- it'd point you onto the right track with the most recent info reported

[Sprech]

As the weather is now good, the problem has gone away. Starts first time. Called the garage to discuss, as I was meant to bring it in today, but if it starts first time I'm not sure they can diagnose much.

They suggested fly wheel clatter, and hinting it needs to be changed, although it was changed at 70K - it's done 108K. Here a video from this morning:

https://www.youtube.com/watch?v=6pHHr403A6c

Clatter? I'm not sure what it sounds like.

[Sprech]

They say they won't do an amp test with clamp. It's not something they normally do and they don't know how much a good starter motor should draw (they're VW/Audi specialists). I don't understand why.

They want to replace the starter motor because it's a reconditioned one - but from what I understand this is common. Some £200 + 1.5 hours labour. Considering they already cost me £500 for not fixing anything, I'm actually feeling a bit miffed to be honest.

I just don't understand why they don't do the amp test? Looks easy to me, apols but I'm no mechanic, but it should be possible to remove a fuse to the fuel pump, and then crank?

[RichardSEL]

As the weather is now good, the problem has gone away. Starts first time. Called the garage to discuss, as I was meant to bring it in today, but if it starts first time I'm not sure they can diagnose much. <snip>

Lead-Acid batteries will deliver marginally more power (thus increase crank speed) in warmer weather rather than colder. That means your battery's nearly finished rather than fininshed. My old factory-fitted Moll was fine in summer and those last warm autumns we had. But come the colder winter, would give a lower crank speed. Perhaps could've taken it through to the next spring, as that winter was mild but didn't want to risk it if there was a freeze. It was my daily commuter

You can only get an indication of whether the starter motor's drawing too much current on startup. Battery volts should drop to minimum 11V-ish as motor cranks (this is on a petrol 2.0L tFSI, don't know whether TDi's figures are different). The series Ampere test they won't do is probably because they havn't got a series Ampere meter that reads up to 40A. I was suggesting the series Ampere test for the drain to see whether there's any current being taken when the car's "gone to sleep".

Halfords will perform a battery condition test. The meter they use is a high load taking like 30A and a voltmeter. This needs to be done after the car is parked up in their car park switched off for at least an hour to allow any internal current leaks (which is what old battery's also do) to discharge

Battery problems can be easily diagnosed with the dealer tool VAS or with VCDS. At this distance, don't know how else to help you


They suggested fly wheel clatter, and hinting it needs to be changed, although it was changed at 70K - it's done 108K. Here a video from this morning: VW Passat TDI - listening for flywheel noise... - YouTube (https://www.youtube.com/watch?v=6pHHr403A6c)
Clatter? I'm not sure what it sounds like.

Was it changed for a Dual Mass Flywheel or a cheaper solid one? Only had a manual Passat B5.5 for a year so no DMF problems' experience

[Sprech]

The car has had a brand new battery for a few months, so it's not that.

Why wouldn't they have an ampere meter? It's a clamp, not inline. I bet one can pick one up on amazon for 20 quid (whether it's accurate is another question)

I spoke to another vw specialist yesterday who suggested a simple RPM test on the starter motor... Sounds logical to me.

[niall campbell]

I think you need to check battery amps, should be 12.5volt when switched off and go up to 14.5 volt at 1,500 rpm with heater on full blast and lights on.

Batterys will show dud cells in cold weather and there is nothing to suggest that a new battery can be faulty neither.

It could be the alternator is not fully charging the battery

[RichardSEL]

What is the make of battery that this garage fitted? How much?

I've suggested a VCDS diagnostics Autoscan, but you havn't done that.
I've suggested a series Ampere meter check when vehicle has gone to sleep (multimeter would do this) but you havn't done that
I've suggested a Halfords battery capacity load test, but you havn't done that
I and others have suggested volts check when charging, and on startup, but you havn't done that

What's the point in us replying making suggestions on how to diagnose if you're not going to do any of them?

[Sprech]

I would have thought Mastertechs (in Mitcham, now you know who they are) would have done a VCDS scan.
Mastertechs have done a battery drain test. (why they changed the speed sensor based on a slow first rev, still has me wondering. I'm fairly unimpressed to be sure)
Why do I need Halfords to diagnose a brand new Bosch battery?
I'm selling it. Worst car I've ever had. In a word: Scheisse.

[RichardSEL]

We're not mindreaders. When in your posts did you tell us that the dealer fitted a "brand new Bosch battery"?
Only that the dealer had changed battery. Halfords would've done your battery test for free is why I suggested it.

Never been to Mastertechs. They sure didn't master your problem...
Of course you're right. If you're not happy with the car then move on. Life's too short and all that BS