2015 Golf TDI long crank first start of the day

[Nuje]

Sounds good - thanks for the tip; I'll be sure to give it a try.

 

[radiator]

He said give your fuel system time to get the right pressure. And if during the day nothing similar happens that leave it as it is. Worth try in You case.

 

[Nuje]

Yeah - that makes some sense.
From the time I'd filled up until we parked on that driving day, we were ~900m higher in elevation, and the temperature was 8°C cooler.

So, for sure, there would be some pressure changes inside the fuel system.

 

[Cuzoe]

@Nuje should be taking his time starting the car anyway to avoid the AID induced glow plug indication CEL

 

[Nuje]

@Nuje is an idiot who started the car four times today and forgot every time to do the "ignition on without starting" thing.
(The car did start just fine every time, though)

 

[radiator]

here is my nes vcds scan on morning fire up. A long crank (no sound because screen capture soft used)

What can you tell do you see any problems or where to find them?

 

[Rochbry]

Hi everyone. Been lurking this thread for a while.
I have had long cranks, hard starts on my 2013 2.0L A3 TDI.
Recently had crank position sensor replaced. Voltage from old and new was quite different. Mech thinks that was it. Once I got it back, had a few hard starts with longer cranks.
Has stopped doing it now 4+ days. Can the crank position sensor relearn on its own?
Will update this forum as time goes on. I have finished the internet on this issue. I'm convinced it's temperature related as everytime it's happened there has been high heat or humidity. Would love to hear if anyone has got this sorted. Pls keep updating this thread.
Bryan

 

[Nuje]

Since I've done the equivalent of cycling the key (KESSY, so I push START without the clutch pedal down) first before cranking the engine, I've had exactly zero long cranks.
The two times I've forgotten to do that, it's been longer than usual cranks. And then once warm, it's fine.

So, I really do think there's something to the pressure in the tank and/or fuel lines being the culprit, and it being addressed by the in-tank pump doing something to sort that out before cranking.

Big temp and / or atmospheric pressure changes would cause some of that.

As an aside to this issue: When I'm filling up the car, I'm a "trickle in the last litre or so, such that I can see diesel in the filler neck" fuel pumper.
I wonder if this contributes or exacerbates the issue.

The other people who have this issue: are you similar "fill-to-the-brim" types?

 

[radiator]

My mechanic says that golf 7 is a new generation car with lots of sensors and if they are no good, vcds shuld give you an error. Says also that fuel pressure in my case is not a problem cos if the fuel pump (the one under the rear seat) had sth wrong with the pressure. vcds should give that message na vcds. furthermore, he clames that we should seek the problem with either leakage fuel , or fuel goes back to the tank, or even there is sth wrong with the current which cannot give enought curent fot the starter to 'fire up' the engine. No blind replacing pparts he dadvices as it will drain our pockets and may not solve the problem.
No idea what to think of that.

 

[radiator]

Small updade. I have been testing - according to mechanic \s advice with outside temperature. Above 15 celcius (16 and up) long crank appears. Lower than 15 no long crank. Don't know what else to diagnose on vcds.

 

[Rochbry]

My mechanic says that golf 7 is a new generation car with lots of sensors and if they are no good, vcds shuld give you an error. Says also that fuel pressure in my case is not a problem cos if the fuel pump (the one under the rear seat) had sth wrong with the pressure. vcds should give that message na vcds. furthermore, he clames that we should seek the problem with either leakage fuel , or fuel goes back to the tank, or even there is sth wrong with the current which cannot give enought curent fot the starter to 'fire up' the engine. No blind replacing pparts he dadvices as it will drain our pockets and may not solve the problem.
No idea what to think of that.

My crank position sensor's voltage was way off compared to the new one that was put in. Vcds did not log the difference. Since changing it, my starts have been 100 percent normal. That being said, I am not in the warm humid weather anymore either. So who knows.

 

[pedroYUL]

For me, it used to be just my wife's CRUA GSW, which did get better with a new battery, then back to eventual long cranks. Changed lift pump, got better, then back to random long cranks.

Then my CVCA Passat started doing the same, after some 2 years no issues. New batt, better for a while, new lift pump, better for a while...

Then I read a post of someone fighting a random fail of the crank position sensor, and got me thinking about it.

This: https://forums.tdiclub.com/index.php?threads/random-engine-hesitation.522147/

The kicker is, that both cars do have a slight bucking every cold start, but then goes away. I do suspect a flaky sensor somewhere.

Like most here, this is only an issue in the summer, never in the winter, and I most def don't have an issue with fuel, since I have brand new lift pumps.

 

[radiator]

pedroYUL
So what is your nest step? Are you going to do (if so what?) to eleminate the problem?

 

[pedroYUL]

pedroYUL
So what is your nest step? Are you going to do (if so what?) to eleminate the problem?

For me, the problem is just an annoyance. Eventually, I will try and log crank position sensor signal and see if there is anything out of place, like in the thread I quoted.

Otherwise, I will just change the sensor.

 

[Victor Huge]

Wanted to report that my long cranking got worse and worse this summer until eventually, after two interrupted regens where the fan runs a while after shut down and short trips in between, the car wouldn't start due to dead battery. Gave the battery a charge and only managed to put in 10Ah out of the 68 or 70 the battery has stock but it started perfectly from then on. Put in a replacement AGM (with coding and everything) from Canadian Tire and it starts forcefully in under a second. I say forcefully because it turns over QUICK... never heard the starter go that fast.

Never would have thought the battery was the issue but here were are.

Update: I've had the occasional longish crank but the new battery really helped things.

 

[jerrymander]

Do the people with long cranks have OEM tuning?

 

[Nuje]

Affirmative here.

I'll just as an update, too, that ever since I've cycled the ignition (hit START button) before cranking the engine, I've had exactly zero long cranks.

If I do that, it fires within a second, every time.

 

[FJBGTD]

The only time I have ever had a long crank is when I crank before the glow plug light has gone out. With the keyless system you should press the start button, then push down the clutch or brake pedal (depending on model), wait for the glow plug light to go out then press the start button again.

 

[Nuje]

When you say "you should...." is that a known "best practice" or in the manual or something?

The way push-button start works in my car is that it won't crank the engine until the glow plugs have finished glowing. So if it's 0°C outside, if I push in clutch/brake and hit START right away, the car waits a good 3-4sec or whatever while the glow plugs do their thing, then cranks. And even if I let go of the START button right away, the car keeps cranking. In warm weather even, there's still a slight pause after hitting the button.

(This messed with me a bit working on a Mk6 a while ago....couldn't figure out why the car wouldn't start: The engine would start to crank then immediately stop .
Took me a couple of tries to realize that push-button start was more like turning the key in a traditional car - the car cranks as long as the button is pushed, but stops as soon as you let go of it).

 

[FJBGTD]

When you say "you should...." is that a known "best practice" or in the manual or something?

The way push-button start works in my car is that it won't crank the engine until the glow plugs have finished glowing. So if it's 0°C outside, if I push in clutch/brake and hit START right away, the car waits a good 3-4sec or whatever while the glow plugs do their thing, then cranks. And even if I let go of the START button right away, the car keeps cranking. In warm weather even, there's still a slight pause after hitting the button.

(This messed with me a bit working on a Mk6 a while ago....couldn't figure out why the car wouldn't start: The engine would start to crank then immediately stop .
Took me a couple of tries to realize that push-button start was more like turning the key in a traditional car - the car cranks as long as the button is pushed, but stops as soon as you let go of it).

Mine does not work like that, regardless of the outside temperature, if I push down the clutch and press the start button it cranks immediately and does not wait for the glow plug light to go out. Perhaps its just my model, 2016 GTD with EA288 engine.

 

[pedroYUL]

Do the people with long cranks have OEM tuning?

Yep. Whatever latest firmware with 2nd part fix

 

[radiator]

I have done some more vcds research and to my two mechanics I should refer to the starter.

I know it is in polish as so I needed to do use polish ver for polish forum.
The first line engine speed rpms -no idea if my translatio is ok,
the secon line is camshaft speed
the last one fuel pressure.
But still I don't know why under 15 celcius it starts fine but above it is not. One of my magic mechanics advises to replace camshafte sensor as it is cheap and the job fast.

 

[DFDJ]

Long crank problem on first start of the day started this summer on my 2015 GSW. Pushing the start button without stepping on the brake for a while has been a good work-around. Once the weather got colder, the long crank prob disappeared only to return in the last couple of days when the nights have not been as cold. I'm in agreement with R's mechanic that outside temp might have something to do with the problem and I'm wondering if it is possible to raise the temp at which the glo plugs turn on from 40F, or whatever the OEM setting is, to maybe 60F. I've got a friend with a VAG-Com and would appreciate any input on where and how to change this setting

 

[Rochbry]

Long crank problem on first start of the day started this summer on my 2015 GSW. Pushing the start button without stepping on the brake for a while has been a good work-around. Once the weather got colder, the long crank prob disappeared only to return in the last couple of days when the nights have not been as cold. I'm in agreement with R's mechanic that outside temp might have something to do with the problem and I'm wondering if it is possible to raise the temp at which the glo plugs turn on from 40F, or whatever the OEM setting is, to maybe 60F. I've got a friend with a VAG-Com and would appreciate any input on where and how to change this setting

I had the exact same issue and replacing the crank position sensor seems to have fixed the problem...
Might be a good dart to throw at the board.

 

[radiator]

I replaced camshafte sensor for a new one. The problem, at first apeared the next day after the replacement. Next day was good no crank. My friend who ownes mk7 adviced me to turn the lights to zero position as a have coming/leaving home on. In the mornig light sensor turns on my lights. So said try to start engine only on zero position. I has been no long crank for 5 days now. No idea for how long. But strange. During te samer (new battery fitted at the end od may 2022) no light were turned on in the mornig and long crank in the morning appeared.

 

[Rochbry]

I replaced camshafte sensor for a new one. The problem, at first apeared the next day after the replacement. Next day was good no crank. My friend who ownes mk7 adviced me to turn the lights to zero position as a have coming/leaving home on. In the mornig light sensor turns on my lights. So said try to start engine only on zero position. I has been no long crank for 5 days now. No idea for how long. But strange. During te samer (new battery fitted at the end od may 2022) no light were turned on in the mornig and long crank in the morning appeared.

After my cps was changed it did a really ****ty start the next day. Was flawless after. I think the computer was learning the new sensor. Has been fine since.

 

[radiator]

I'll give you the feedback if long crank in the morning still persists or not. I bought cps from official porshe, audi, VW dealer it was discunted but on the package was exp date september 2021. Isn't it strange ?

http://imgur.com/UhB6PVY

Autopart manufacturer I guess it may not be reliable but I don't know.
To sum up. I believe that the starte gets too little current to 'swing' camshaft hence it (cps) is lazy to 'run' right away together with crankshaf

 

[Rochbry]

I'll give you the feedback if long crank in the morning still persists or not. I bought cps from official porshe, audi, VW dealer it was discunted but on the package was exp date september 2021. Isn't it strange ?

http://imgur.com/UhB6PVY

Autopart manufacturer I guess it may not be reliable but I don't know.
To sum up. I believe that the starte gets too little current to 'swing' camshaft hence it (cps) is lazy to 'run' right away together with crankshaf

Just so I am aware, the crank position sensor and the cam sensor are two different parts right?
I replaced the crank position sensor in my 2013 Audi A3 TDI

 

[Rochbry]

Just so I am aware, the crank position sensor and the cam sensor are two different parts right?
I replaced the crank position sensor in my 2013 Audi A3 TDI

Rear main seal area, tone wheel and crank pos sensor

 

[radiator]

What Rochbry showed is crank sensor and it is a bit difficult to get to and replace. Still don't know if the part I posted is reliable or not? What do you think?