Help troubleshooting problem starting when really cold

[Antisladd]

Hello! I've got a quite troublesome problem with my Skoda Yeti which I need help solving. The problem is that when it's about -10 degrees Celsius or colder outside, the engine starts just as normal but cuts off after about 2 seconds. It usually correctly starts after I've waited maybe 5 minutes from the first attempts, and once started it runs fine and have no problem re-starting if i turn it off.

 

I've read some topics suggesting everything from pump to relays, but none seems to have in common that it only happens when it's been sitting for a while in a really cold weather.

 

Any suggestions where to start troubleshooting? I do own a VCDS cable that I bought for this exact problem, but I do not really know how to use it besides scanning for codes.

I've really got no idea where to start really, and it's not easy since I need a really cold weather for the problem to appear.

 

Oh, and it's a year 2011 Skoda Yeti with a 2.0 TDI, 140hp diesel engine with 4x4 DSG.

 

Some clues about the problem:

* When it shuts down its often a "clean" shut down, just as if I've turned the key. It has however on some occasions been a rough shutdown.

 

* I've scanned for codes but there are none (except for broken bulbs - I've fitted LEDs)

* The immobilizer light does not flash, and I've also tried several keys just in case.

* It only happens if the car has been sitting several hours when it's -10C outside.
* Once it started correctly it runs and starts just fine every time after that.

* I've checked and cleaned the intake and flap (anti-shrudder valve I believe?), and also did the EGR nozzle rotation fix.
* The anti-shrudder flap is not stuck in a closed position.

 

* It seems to start with the EGR pipe removed from the intake, however I've only had one chance to try this so it might just have been luck

 

* I've tried to check the relays under the dash, but I could not find a setup online that looked like mine does, so I do not know which relay does what. I did try to remove the relays one by one to see if I could reproduce the problem, which I could not. There was however some relays further in behind under the dash which I could not figure out how to reach.

[Antisladd]

Forgot to add (and I can't find any Edit button?):

 

If I run the auxiliary heater some time beforehand it seems to start up no problem 100% of the times. Unfortunately the aux pump seems to have died today (according to the code I got), so I'm hoping the weather stays mild.

[Urrell]

Sounds like water freezing in the diesel, probably in a filter.

[Ootohere]

Welcome.

Hopefully someone can help.

 

What country are you in and has your fueling meant that you have winter spec diesel in so with Anti-waxing.?

[Urrell]

9 minutes ago, Antisladd said:

Forgot to add (and I can't find any Edit button?):

Click on the 3 dots on the top right of post

[KenONeill]

8 minutes ago, Antisladd said:

Forgot to add (and I can't find any Edit button?):

 

If I run the auxiliary heater some time beforehand it seems to start up no problem 100% of the times. Unfortunately the aux pump seems to have died today (according to the code I got), so I'm hoping the weather stays mild.

Edit is on the ellipsis "..." symbol top right of the post, for the first hour.

 

Beyond that, I'd agree with @Urrell that it sounds like water freezing in a heated fuel line.

[Antisladd]

3 hours ago, Urrell said:

Sounds like water freezing in the diesel, probably in a filter.

 

3 hours ago, roottoot said:

Welcome.

Hopefully someone can help.

 

What country are you in and has your fueling meant that you have winter spec diesel in so with Anti-waxing.?

I'm located in the upper parts of Sweden, where temperatures of -25 is not uncommon, so I doubt it's the actual fuel that's the problem. This is the second winter we've experienced the problem.

 

Freezing water might be something, but where to look and what to do? I have fairly OK knowledge of petrol engines, but I'm totally lost when it comes to diesel.

Also, I can try to start it 10 times in a row and it always does start for 1-2 seconds. Wouldn't it fail to start after the first tries of the diesel has ran out?

 

3 hours ago, Urrell said:

Click on the 3 dots on the top right of post

Strange, I only have "Share" and "Report". Might be a new-account problem, I read that some functionalities of the forum are disabled when you are new.

[Ootohere]

In the upper part of Sweden it is Winter Diesel that is sold all year so that should not be an issue if that is what is in the tank.

 

If you had the issue last year as well then when was the car serviced and did you not ask the mechanic?

When was the Fuel Filter last changed or the Air Filter looked at/ checked or replaced?

 

........................................

The time you have to edit is limited if you are not a Freedom member.

 

If you could not within an hour then maybe there was an issue.

If you were only trying over an hour after posting having been told where the EDIT was then no problem.

 

 

Edited 8 February, 2022 by roottoot

[Urrell]

That's what I remember but I am 14 hours from my last post and the edit option is still available.

[Ootohere]

^^^ were you a Freedom member in the past so still getting the benefits?

[Urrell]

No, but I remember only getting about 1 hour in the past.

Edit: Looking back at my posts seems its probably 24 hours now as I can still edit a 22 hours old post but no further back than that.

Edited 8 February, 2022 by Urrell

[KenONeill]

22 minutes ago, roottoot said:

^^^ were you a Freedom member in the past so still getting the benefits?

I am still getting Edit action available, was a Freedom member, but then I am also a Grand Master (but not I note now or next going to be a Renegade Master).

[Antisladd]

3 hours ago, roottoot said:

In the upper part of Sweden it is Winter Diesel that is sold all year so that should not be an issue if that is what is in the tank.

 

If you had the issue last year as well then when was the car serviced and did you not ask the mechanic?

When was the Fuel Filter last changed or the Air Filter looked at/ checked or replaced?

It was serviced last summer, not a shop but a fairly skilled hobby-mechanic . He had no idea for a solution of the problem, he suggested trying to change the battery. But if I recall correctly I did try to jump-start it last winter with no success.

 

I would guess it was at least checked on upon the service, but I'm not 100% certain as the wife was handling the contact with the mechanic.

[Ootohere]

Off topic to your issue,

but have you had the Haldex serviced?

[Antisladd]

2 hours ago, roottoot said:

Off topic to your issue,

but have you had the Haldex serviced?

No, not during the two years we've owned the car. Not sure about previous owners.

[Ootohere]

Haldex servicing is @ 3 years / 30,000 miles or sooner maybe because of type of use / environment.

[SurreyJohn]

My guess is water or moisture that is freezing.
Not very much but some in the fuel line from the tank

 

Try getting the fuel filter cleaned, (or replaced)

and if they can, flush the fuel line to ensure no traces of water it would help (but possibly this will be too troublesome to do and only do it if everything else is not working)

 

A couple of other possibilities include faulty temperature sensor or faulty injector, but I don’t think this is main problem as would not run correctly for first 10-20 minutes when engine is not warmed up.

 

 

[Antisladd]

On 08/02/2022 at 15:45, roottoot said:

Haldex servicing is @ 3 years / 30,000 miles or sooner maybe because of type of use / environment.

I'll look into it, thank you.

 

12 hours ago, SurreyJohn said:

My guess is water or moisture that is freezing.
Not very much but some in the fuel line from the tank

 

Try getting the fuel filter cleaned, (or replaced)

and if they can, flush the fuel line to ensure no traces of water it would help (but possibly this will be too troublesome to do and only do it if everything else is not working)

 

A couple of other possibilities include faulty temperature sensor or faulty injector, but I don’t think this is main problem as would not run correctly for first 10-20 minutes when engine is not warmed up.

 

 

I have no problem wrenching on cars, it's just that I'm not familiar with a diesel engine. I'll try to find information about it! I've read somewhere that I can activate the fuel pump with VCDS, would removing the filter and catching the diesel be the procedure for a flush?

I tried to read temperature on the sensors I could find in VCDS and none seemed off. But I could have missed some.

[Antisladd]

Working on the water in fuel theory, any idea where the fuel could have frozen? As it seems to start every time the auxiliary heater has been running, wouldn't that impend that the problem is under the hood?
Also, does the aux heater share fuel line and pump with the engine?

[Antisladd]

New year, newish problems!

 

I did a fuel filter swap, and did drain all the fuel from the canister where the filter are placed. Thought I could see some water at the bottom of it, and was hoping this was the solution.. but it was not. The car are still acting up. However, now does "cough" to death instead of the previous clean "cut off". Seems like it's starving for fuel or air, or are getting the wrong mix of it.

 

Well so now I'm basically back to square one again. Any suggestions of what to try out for now?

Are there any more filters, or areas where I can try to drain of water?

 

I've added a video of the current problem. After the first start I'm blipping the throttle to try to keep it alive.

NOICE WARNING, was using the Defa heater when I recorded it.

 

[Carlodiesel]

There is a fuel return hose on the fuel filter.

With the engine idling use a small can to catch what comes out.

At idle there should be fuel wanting to return to the tank. Just check you have that.

If you don't have that, its possible your fuel is freezing.

 

Worth a check.

 

[J.R.]

Does it run at all at higher temperatures or will it not run at all since the filter replacement?

 

If its the latter then you need to purge the air out of the system using VCDS or similar, it might also be possible by turning the ignition on and off multiple times but I'm not sure if that can be done on the CR engine.

 

Your original problem of the hard cut after 2 seconds running at below minus 10° I believe was the immobiliser and I reckon it is as a result of a fractured soldered joint on between the connector and the PCB on the instrument panel.

 

Good luck!

[Antisladd]

23 hours ago, Carlodiesel said:

There is a fuel return hose on the fuel filter.

With the engine idling use a small can to catch what comes out.

At idle there should be fuel wanting to return to the tank. Just check you have that.

If you don't have that, its possible your fuel is freezing.

 

Worth a check.

 

Are there any distinct way of knowing which one is which or do I just have to google it for this engine model?

Unless contaminated from the tank I do not think it's the diesel per se, as stated I'm living in the norhtern part of Sweden and have other VAG diesel engines which have no problems with the same fuel.

 

23 hours ago, J.R. said:

Does it run at all at higher temperatures or will it not run at all since the filter replacement?

 

If its the latter then you need to purge the air out of the system using VCDS or similar, it might also be possible by turning the ignition on and off multiple times but I'm not sure if that can be done on the CR engine.

 

Your original problem of the hard cut after 2 seconds running at below minus 10° I believe was the immobiliser and I reckon it is as a result of a fractured soldered joint on between the connector and the PCB on the instrument panel.

 

Good luck!

It runs just fine in all temperatures, once "correctly" started. The start-problems are usually when it's below -10C, but last time it was about -5 (however it did actually try to run and not hard-cut). No problem what so ever if it's warmer.

I did run the pump(s?) for about 1 minute using VCDS when I changed the filter, and it started right up making me believe for a while the filter was the problem.

 

Hmm good theory! But wouldn't that throw a code? It starts just fine basically 100% of the times if I use the diesel aux heater, but not if I run just the Defa-heater (cabin only), implying that the temperature in the cabin does not seem to matter.

Edited 6 January, 2023 by Antisladd

[Antisladd]

Seems like a bad joke but the problem got worse AGAIN about a year since last time! Funny enough the problem seemed to have gone away earlier this season as it always started up even in -25 degrees.

 

Anyway, the problem now is that it started to run poorly when my wife was drivning it, and since she turned it off it has not started at all even in "mild" temperature (0 degrees).

It starts for about 2 seconds with a poor and jerky idle, and then dies. 

 

I did try to run the auxiliary heater and it ran a bit better, but it would not rev past 1300 rpm unless I was blipping the throttle, in which case i could "trick" it up to 2000 rpm. But puttning it in gear and try to drive caused it to stall. 

 

I've disconnect the fuel line from the tank and ran the pump with VCDS for 10 seconds, and it pumped about 100-120 ml of fuel, which would be 0.6-0.8 L/min. I cant find the correct specs for my car, but it seems a bit low? 

 

I also noted that the car has a secondary fuel pump under the hood. It would be a plausable culprit as well as its located besides the fuel filter, on the same side as the auxiliary heater which would make it receive some heat from the heater and explain why the car started easier when the heater was run. But i have bo idea of how to test that pump. 

 

Any idea what to do next besides throwing parts at it? 

Edited 17 January by Antisladd
Added info about the rpm.

[Antisladd]

Update in case it helps someone; the shop told me the EGR valve is the problem. 

 

They quoted 1900€ for a repair. Anyone know if there are any other options? I've seen something about egr and dpf delete, but it seems like as much work removing the dpf as to replace the EGR?