TDi 170 (08) sudden poor starting this morning

chinnyhill10

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Hi,

Had my 08 plate TDi 170 for about 6 weeks.

It's been starting fine, but this morning it failed to start. Just the starter motor going around, no attempt to turn over. Like a petrol engine starved of petrol almost.

Eventually (after 4 minutes of trying) it spluttered into life with a rough idle at 1000rpm. It carried on like this for a mile or so down the road and then turned into its normal self.

Other then a very quick flash of an ESP Fault on the dash (probably related to turning the car on and off trying to start it) no faults showed on the dash.

Any ideas? Glow Plugs? Seems off though as this morning wasn't especially cold.

From warm it starts fine and obviously I can't test it cold again yet.

Thanks.
 
I'm no expert, but the esp message I get on mine as many others do related to low volts on battery or possibly because it turned over a lot

The 1000 rpm I would imagine is ir doing a dpf regen, don't get me started on this subject though, lol

Hope this helps a bit
 
Today was a really cold morning in yorkshire...so could be either the battery or the glow plugs...Mine did this for a while and it turned out to be one of the glow plugs and the battery, which wasnt taking on any charge...
 
Surely it wouldn't try and do a regen from a cold start though would it?
 
Doubt it would be a regen at that point in time. Silly question, but did the glow-plug light come on, and then go off after a few seconds?
 
I think the glow plug light came on and went off as normal. It wasn't that cold either, about 10c.

I've been driving around in her all day and she's been fine including from a 5 hour cold start. Put a dose of Redex in just in case.

I'm hoping its just something daft like the glow plugs. My Golf MK5 had some shafted glow plugs which only showed up under VCDS. No other symptom other than rough starting.

One thing it has made me do is finally get around to buying VCDS. I've owned VAG cars for the past 13 years and we currently have 2. All the money I've paid in diagnostics is naff all compared to just buying my own system. I'm hoping it might shed some light.

DPF regen at that point would be unlikely as the ECU won't initiate it until the temp reaches 600c. That wouldn't happen seconds from starting.
 
Get ur battery tested mate. Halfords do it for free. They do an alternator test too if the battery seems ok.

If that battery and alternator are both ok, then go get a diagnostics check done.
 
Will do. I have a full VCDS setup arriving shortly. The steep price will be offset by just how much I've paid for diagnostics down the years!
 
If you need a battery, its the Varta E44. Well documented on here, I got one recently £75 from Amazon.

Good luck!

S
 
The only place I could see selling the full proper version was a company calling Genden.

Yes you could get a cheap cable and use the "Lite" version of the software but what's the point if you are missing half the features?

Cost is £263 which seemed steep until I worked out how much I'd spent on diagnostics + time out for both our VAG cars over the past few years.
 
And this morning it did it again. Really hard to start her.

Starter was going, but this time "Oil pressure" flashed up on the display. Eventually she started and this time without the increased revs (although still white smoke coming out of the back).

Just ran VCDS on her and the only engine related fault I could see was:



1 Fault Found:
001137 - Exhaust Pressure Sensor 1 (G450)
P0471 - 006 - Implausible Signal - Intermittent
Freeze Frame:
Fault Status: 00000001
Fault Priority: 1
Fault Frequency: 2
Reset counter: 40
Mileage: 78889 km
Time Indication: 0
Date: 2012.10.15
Time: 16:47:45


Freeze Frame:
RPM: 0 /min
Torque: 0.0 Nm
Speed: 0.0 km/h
Pressure: 0.0 mbar
Text: -42 mbar
Text: 112 C
Temperature: 39.0∞C

I'm assuming that can't be it. Could it?

Cheers.
 
I had the same fault couple of months ago. Kept coming up with that error when scanning with VCDS even after clearing the fault, Dannykn9 helped me replaced the G450 sensor and no errors ever since. He's a top bloke.

And this morning it did it again. Really hard to start her.

Starter was going, but this time "Oil pressure" flashed up on the display. Eventually she started and this time without the increased revs (although still white smoke coming out of the back).

Just ran VCDS on her and the only engine related fault I could see was:



1 Fault Found:
001137 - Exhaust Pressure Sensor 1 (G450)
P0471 - 006 - Implausible Signal - Intermittent
Freeze Frame:
Fault Status: 00000001
Fault Priority: 1
Fault Frequency: 2
Reset counter: 40
Mileage: 78889 km
Time Indication: 0
Date: 2012.10.15
Time: 16:47:45


Freeze Frame:
RPM: 0 /min
Torque: 0.0 Nm
Speed: 0.0 km/h
Pressure: 0.0 mbar
Text: -42 mbar
Text: 112 C
Temperature: 39.0∞C

I'm assuming that can't be it. Could it?

Cheers.
 
I had the same fault couple of months ago. Kept coming up with that error when scanning with VCDS even after clearing the fault, Dannykn9 helped me replaced the G450 sensor and no errors ever since. He's a top bloke.

Were you having trouble starting from time to time?

Interesting that the fault occurrences are the same number of times the car didn't start which is why I ask.

****** VAG and their sensors! I thought they'd got over this problem! My old Golf mk4 suffered from multiple sensor failure and electrical problems but my mk5 was very solid. I thought they'd got over all of this!
 
Like i said before no problems starting ever since but will be replacing battery soon before its gets cold. Had a few problem starting the car back in Nov 2011 after replacing injectors so recharging the battery did the trick. Now car and battery is 5 years old so replacing for the sake of it. Batteries tend to be unreliable when past their sellby date.
 
So here we are again :)

Sensor replaced just under 2 weeks ago. No problems until this morning when it was a pig to start again.

The common factor seems to be Monday mornings after the car has been left since Friday evening. Again it wasn't that cold but what could cause the car to get upset after being left for 2.5 days?

Just had the battery tested at the local auto factors and they said it was fine.

I'll get VCDS run over it again later but I suspect it will show nothing.
 
As suspected, nothing on VCDS. As far as the car is concerned, nothing happened! Which is odd considering how it was warning me of "Low Oil Pressure".

Have left it parked overnight on a hill with the nose pointing up just to see if there is anything in the suggestion I've seen elsewhere that the fuel runs back into the tank.
 
Update on this (sorry, it's getting a bit tedious)....

Read various things about 170's not starting when parked nose up on a hill so parked it like that last night. Returned this morning and it was a utter pig to start. Far worse than before. All I could hear for the first couple of attempts was the starter. No attempt at all to fire.

So it seems to me that the engine is being starved of fuel either through being left for a few days or if it is parked nose up.

Some kind of fuel return valve etc? Garage are doing some research into this for me.
 
Update on this (sorry, it's getting a bit tedious)....

Read various things about 170's not starting when parked nose up on a hill so parked it like that last night. Returned this morning and it was a utter pig to start. Far worse than before. All I could hear for the first couple of attempts was the starter. No attempt at all to fire.

So it seems to me that the engine is being starved of fuel either through being left for a few days or if it is parked nose up.

Some kind of fuel return valve etc? Garage are doing some research into this

hi buddy I've been working on this, I'm 100% sure it's fuel leaking back to tank, tested lift pump and only ever happens after its been stood for 72hrs plus, does anyone with vag experience know of any reason I can't fit a none return valve after filter and before pump? I'm of the assumption the valve in my tandem is not working and this seems a likely fix and good route for fault finding! Also fitting some clear pipe after fuel filter isn't a bad idea to see what's actually in there. Hope this can help you! Andy .
 
Cheers. I'll forward this to the garage. Looks like it had a new Tandem pump in Nov last year according to the service docs. Docs say it was "breaking up". Wonder if the replacement is also failing?

Thanks.
 
I'm having the exact same issue with my 2007/57 plate B7 A4 TDi 170.

Happens randomly, can go for weeks without doing it, although Monday mornings after being sat unused since Friday was quite a common time for it to happen.

Parked on a slight hill, nose pointing up.

Extended period of cranking before firing up, little lumpy for a few seconds then ok.

Never any fault codes when scanned with a Snap-On SolusUltra.

Tried new fuel filter, cleaned MAF sensor, EGR valve, anti-stall valve, and most electrical connectors.

I have a new coolant temp sensor to try when i get round to fitting it.

I started to think it was loosing fuel pressure over a period of time but i didnt use my car for 4 days the other week and it fired up straight away.:uhm:
 
I very much doubt this is a fuel leakage or drainage issue as when you turn the ignition the lift pump pressurises & primes the fuel lines. If you want to be 100% try turning on the ignition till the glow plug light goes off, then turn the ignition off and on again wait for the glow plug light to go out again & then try starting the engine. By doing this you will have primed the fuel lines twice & there's no way they will be full of air or have no fuel at the injectors.
 
I very much doubt this is a fuel leakage or drainage issue as when you turn the ignition the lift pump pressurises & primes the fuel lines. If you want to be 100% try turning on the ignition till the glow plug light goes off, then turn the ignition off and on again wait for the glow plug light to go out again & then try starting the engine. By doing this you will have primed the fuel lines twice & there's no way they will be full of air or have no fuel at the injectors.


Im can agree with that, the lift pump does fire a good amount of diesel into not a lot of fuel line, but from experience it doesnt matter how good the pump is if it's pushing against air trapped further up the system? Some systems (old ones) require cracking at injectors to overcome this? I mean it could all be circumstance ( nose uphill etc) but logical.
 
Mine is back at the garage where they are now looking at it. Hoping they can reproduce the problem (they are going to leave it parked nose up overnight).
 
Both 170s I have had been noticeably reluctant to start from an overnite cold start when temps get in to single figures. It goes from starting perfectly normally to taking longer turns of starter or catches and dies then restart rough. On my first car I changed the glow plugs but it did not make any difference.

When my 2nd 170 showed the same symptoms I just ignore it and know it's temp-related. Sub 10degrees shouldn't cause an issue but it just seems to on these engines in my experience!
 
To clarify, my issue is not temperature related.

Anyway, earlier had a phone call from the garage. They left it parked on a ramp overnight with the nose up and lo and behold it wouldn't start. Was very glad to hear they had managed to reproduce the problem!

So far they have established that the fuel is draining out of the injectors so that the car has no fuel to start with. They are now looking into why this may be the case. Possibly a faulty lift pump but they need more time to investigate.

Will let you know when I hear more.
 
Sounds like it could be the injector seals then.

I'm contemplating doing mine although its had the injector recall 6 months ago.

Why it does it so randomly i still cant understand though??

Keep is posted, as i'd like to sort out this problem.
 
They've finally nailed it down to the lift pump. Replaced it on Friday, left it parked on a ramp all weekend and this morning it started fine.

They suspect there may be a valve or something in the pump that wasn't fully closing, allowing all the fuel to drain back to the tank.
 
Got the car back. Not been left for any long period of time yet (garage test aside) but the one thing I have noticed so far is that she starts quicker when you turn the key. Where before there would be a tiny hesitation she now fires up straight away.

The proof of the pudding will be in the eating though (or rather the driving).
 
Be interesting to see if this has cured it.

How much was the actual lift pump??
 
I have the same problem withmy 140 bkd. When fuel in tank is less 1/2 it's hard to start in the morning..

When the car is parked on a hill for 4-5 hours with nose down it starts instantly...