VW 2.0 TDI 140 wont start when warm
Discussion
Hi all
I have a 2009 Passat 2.0 TDi, and it start relatively fine normally (I say relatively as sometimes it can take quite a few chugs before it starts, but always first time), but after a drive where the engine has gotten fully up to temp for a while, if I stop it, and then shortly after try to start it again (for example after filling it up, or going into the shops quick), it wont start.
It turns over, but just wont take, and I then click the key out, put it back in, repeat 4 or 5 times, and eventually it starts.
I always wait for the light that shows the plugs are up to temp to go off, don't run anything electrical like air con or wipers etc, so cant figure out why it does this.
I would expect if it was a battery fault it would be consistently difficult to start, so does anyone have any ideas? It's a serious pain, and Im hoping it doesn't get worse.
I have a 2009 Passat 2.0 TDi, and it start relatively fine normally (I say relatively as sometimes it can take quite a few chugs before it starts, but always first time), but after a drive where the engine has gotten fully up to temp for a while, if I stop it, and then shortly after try to start it again (for example after filling it up, or going into the shops quick), it wont start.
It turns over, but just wont take, and I then click the key out, put it back in, repeat 4 or 5 times, and eventually it starts.
I always wait for the light that shows the plugs are up to temp to go off, don't run anything electrical like air con or wipers etc, so cant figure out why it does this.
I would expect if it was a battery fault it would be consistently difficult to start, so does anyone have any ideas? It's a serious pain, and Im hoping it doesn't get worse.
might be the same as our 1.9tdi.
Same symptoms anyway, once hot trying to restart after a run or after fueling for example was hit and miss. It would turn over but not fire.
Theres a relay, on the mk4 its under the steering wheel in the fuse box. I forget what its number is, but its one of the main relays to actually get the car going. when it starts to fail it gets really hot, and its this whcih yuo have to wait to cool down.
Next time it happens pop the cover off and see if you have a hot to touch relay, might be the culprit!
Same symptoms anyway, once hot trying to restart after a run or after fueling for example was hit and miss. It would turn over but not fire.
Theres a relay, on the mk4 its under the steering wheel in the fuse box. I forget what its number is, but its one of the main relays to actually get the car going. when it starts to fail it gets really hot, and its this whcih yuo have to wait to cool down.
Next time it happens pop the cover off and see if you have a hot to touch relay, might be the culprit!
spats said:
might be the same as our 1.9tdi.
Same symptoms anyway, once hot trying to restart after a run or after fueling for example was hit and miss. It would turn over but not fire.
Theres a relay, on the mk4 its under the steering wheel in the fuse box.
You are thinking of relay 109. Same symptoms anyway, once hot trying to restart after a run or after fueling for example was hit and miss. It would turn over but not fire.
Theres a relay, on the mk4 its under the steering wheel in the fuse box.
Top Tip - as this relay begins to fail, when the car refuses to start the glowplug light will not show at all. Once the relay recovers, engine power is supplied again, the gloplug light shows, and it'll start.
So, for the OP, when this happens do you see the glowplug light at all?
The 2.0 TDI 140 is known for it. It's a combination of lazy starter motor and bad software normally. You can have it remapped out.
IIRC when hot, the ECU doesn't fire the injectors until above ~300rpm, which the lazy starter motor isn't getting the engine up to. When cold it injects diesel straight away to aid starting.
New starter motor cures it until the replacement gets old, or the software edit may get a few extra years out of the current starter.
The quick and dirty fix is unplug the coolant temp sensor (G62 I think) at the rear right of the engine block when starting it, as it defaults to the ECU "cold starting" it.
IIRC when hot, the ECU doesn't fire the injectors until above ~300rpm, which the lazy starter motor isn't getting the engine up to. When cold it injects diesel straight away to aid starting.
New starter motor cures it until the replacement gets old, or the software edit may get a few extra years out of the current starter.
The quick and dirty fix is unplug the coolant temp sensor (G62 I think) at the rear right of the engine block when starting it, as it defaults to the ECU "cold starting" it.
Thanks all, I do see the light on the dash to indicate the glow plugs are warming, which then goes off after a few seconds as expected.
It does sound pretty lazy when it tries to turn over, which is why I thought battery, but as mentioned a bad battery would be apparent at all times.
I will look at a remap, is this a VW job or one of the remap firms?
It does sound pretty lazy when it tries to turn over, which is why I thought battery, but as mentioned a bad battery would be apparent at all times.
I will look at a remap, is this a VW job or one of the remap firms?
Depends where you are, Awesome GTI in Manchester, whilst good at what they do, had never heard of the problem apparently. However the remap offered by more-bhp in Crewe(?) can add it to the remap for £35. Whether they will just do the Hot Start fix on it's own, i'm not sure.
VW won't want to change the software, they're more likely to recommend new starter and/or battery.
VW won't want to change the software, they're more likely to recommend new starter and/or battery.
http://www.ebay.com/itm/131966035072?ssPageName=ST...
This seller has three different wiring sets for VAG engines to warm engine start problem elimination. It depend on what kind of engine coolant temperature sensor your car has. All you need to do with these wiring kits is to just plug them in and that is it.
This seller has three different wiring sets for VAG engines to warm engine start problem elimination. It depend on what kind of engine coolant temperature sensor your car has. All you need to do with these wiring kits is to just plug them in and that is it.
I have the same issue on a VW Scirocco 2012 2.0 TDI 140.
I have owned the car for two years and it’s always given me slight trouble when starting. Initially it was slow cranking when cold, and would sometimes take around 3 - 5 seconds to start, which felt like a lifetime. Then the issue went almost entirely, and I completely forgot it had ever even been an issue.
I have recently returned from a trip to Italy, which was roughly around 4000 miles. Towards the end of the trip, the issue came back, but worse. When warm, the car would either crank for about 5 seconds and judder into life, or fail to start after the first or second attempts. When I first noticed this, the temperature outside was between 20 - 30 degrees. This scared me a little - especially the thought of being stuck in the channel ferry blocking an entire row of cars.
I’ve been back in Blighty for 3 weeks now, and it’s worse than ever. It starts fine from cold, but if I try to start it after a run (and it’s up to temperature), it refuses to start until the 4th or 5th attempt.
I’m booked in at a garage in December due to mammoth waiting times, but if anyone has found a fix for this, I’d be very interested to know.
Ps. The car has covered 175k miles, has been serviced regularly, etc etc etc…
I have owned the car for two years and it’s always given me slight trouble when starting. Initially it was slow cranking when cold, and would sometimes take around 3 - 5 seconds to start, which felt like a lifetime. Then the issue went almost entirely, and I completely forgot it had ever even been an issue.
I have recently returned from a trip to Italy, which was roughly around 4000 miles. Towards the end of the trip, the issue came back, but worse. When warm, the car would either crank for about 5 seconds and judder into life, or fail to start after the first or second attempts. When I first noticed this, the temperature outside was between 20 - 30 degrees. This scared me a little - especially the thought of being stuck in the channel ferry blocking an entire row of cars.
I’ve been back in Blighty for 3 weeks now, and it’s worse than ever. It starts fine from cold, but if I try to start it after a run (and it’s up to temperature), it refuses to start until the 4th or 5th attempt.
I’m booked in at a garage in December due to mammoth waiting times, but if anyone has found a fix for this, I’d be very interested to know.
Ps. The car has covered 175k miles, has been serviced regularly, etc etc etc…
I have a 2012 170 bhp version and it does it now and again, on mine though the starter does sound a bit lazy on it so im guessing it could be related to engine cranking speed.
On faults like this you would have to check some things on diagnostic equipment such as cranking rpm and fuel pressure.
Coolant temp sensors were very common on petrol engine cars for this kind of behaviour as are crank position sensors when they get hot.
Good luck with it but it could be hard to pin down.
On faults like this you would have to check some things on diagnostic equipment such as cranking rpm and fuel pressure.
Coolant temp sensors were very common on petrol engine cars for this kind of behaviour as are crank position sensors when they get hot.
Good luck with it but it could be hard to pin down.
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