2015 Golf TDI long crank first start of the day

1945GPW · September 3rd, 2017, 21:06

Hey Guys!! I'm new to the form but have had diesel VW's for about 6 years now. I am more familiar with the MK4 Jetta's but recently purchased a 2015 Golf TDI and I'm really liking it.

Anyway as the title says I'm experiencing a longer than normal cranking period the very first start of the day. After that initial long start it starts normally through the day. What I mean by long crank is the engine turns over approximately 4 to 6 times before it starts. After the first start of the day it will crank about 2 turns and fires right up.

Is anyone else experiencing this and if so whats the fix for it? My golf has 24000 miles. I replaced the fuel filter and its not any better. I'm thinking the HPFP is possibly de-priming over the night causing the extra cranks, what are your thoughts? thanks

1945GPW · September 5th, 2017, 18:22

Don't tell me I'm the only one having this issue lol

Jedadiah · September 5th, 2017, 18:54

The only time I had long cranking on my mk6 was when the battery was on it's way out. Might be worth checking.

sands80 · September 5th, 2017, 19:39

My 2015 has the same exact issue. I too chalked it up to fuel pump depressurizing over night- but sometimes it sits over night, quickly starts in the AM.
It seems random.

Somebody posted a similar thread a while back and I seem to remember that it was suggested that the owner find someone with a VCDS scanner to read and errors that may come up during startup that may not be enough to trip the check engine light.

It may be a crank position sensor ? but I think that would throw a CEL...

As for the battery - mine was replaced for a different issue (leaking acid), but the long crank time symptoms remained.

marcusku · September 5th, 2017, 20:54

Mine does this too and I can't seem to figure out any sort of pattern. For me it's always on a completely cold engine (first start of the day). It doesn't seem to be connected with how long it's been sitting and seems random. I also noticed a slight bit of smoke at start up once when it did this-not sure how it got through the particulate filter. I asked the dealer about it and they hadn't heard of it before. I'd like to know what it is prior to actually taking it to the dealer.

1945GPW · September 6th, 2017, 07:15

Okay so looks like some people are having the same issue. My brother has a 2015 jetta and he is having the intermittent long starts, my parents sportswagen starts normally and my golf has the long starts every morning.

I hooked up my VCDS and checked for codes and nothing came up. I was thinking of getting a graph log of the fuel pressure rail pressure and rpm at first start of the day and then when it warms up doing it again and seeing if there is a difference but Ill have to figure out how to log a graph with the 2015 as the basic function is not working for this year. Anyway if anyone finds out the cause of this please let us know!!

Ted Hurst · September 13th, 2017, 03:59

Mine does the same thing. With my old 2012 JSW I noticed that if I turned on the "ignition" but waited to start the glow plug cycle would be over resulting in a long crank, stumble and sometimes would not start on the first try. So, with the keyless "ignition", what sets off the glow plug cycle?

sands80 · September 14th, 2017, 06:56

Quote:

Originally Posted by Ted Hurst

Mine does the same thing. With my old 2012 JSW I noticed that if I turned on the "ignition" but waited to start the glow plug cycle would be over resulting in a long crank, stumble and sometimes would not start on the first try. So, with the keyless "ignition", what sets off the glow plug cycle?

It makes sense that the extended turning over of the engine has something to do with the glow plug activity. I have had the '15 Golf for a year and a half (still running the original, pre-diesel gate software) and I noticed that during the winter months it always started right up. The longer crank times seem to occur when the weather warms up. Maybe the computer does not use the glow plugs above a certain temp?

Thats a wild guess!

1945GPW · September 16th, 2017, 19:09

I know the glow plugs on my 2005 TDI don't come on when the temp is over 40 but I'm not familiar with the 2015s... I ended up taking the golf to the dealer and had them check the rail pressure hpfp battery and a couple other things. They said everything checked out good so I don't know. Guess its a common thing with these new engines. I hooked up a trickle charger today and I'm going to see if maybe the battery was draining slightly over night to cause the long starts. I'll let you guys know if that seems to fix it.

marcusku · September 17th, 2017, 11:08

There isn't too many things it could be. Engine needs fuel, proper timing, compression, reasonable cranking speed and glow plugs (when cold at least) to start. If not the glow plugs or fuel, could the computer be doing something strange with the timing at certain temps?

1945GPW · September 17th, 2017, 13:32

I had the trickle charger on it last night. Didn't make a difference starting it this morning. Still has the long cranking for the first start then perfect afterwards.

Mine sits in a garage so temp stays about 70 to 80 over night. I guess this winter I will leave the car out and see how it starts in cold weather lol.

marcusku · September 18th, 2017, 17:28

On older ALH TDI's you could unplug the coolant sensor and this would trick the computer into running the glow plugs for an extended period of time since it didn't know what the engine temp was. Maybe it's possible to do the same thing on this engine so see if glow plug operation has an effect?

PoDUB · September 18th, 2017, 19:15

Another Newbie here with the same issue. My wife's 2015 Golf Sportwagen(47,000MI) has just started this occasionally. It has done it 4 times randomly over the last month and never before. Definitely happens when it has not been driven for more than a day, and the nighttime temps are cool but around 50F. I don't think the battery is the issue because crank speed is fine. I would think glow plugs are hardly needed at these temps and on some colder nights around 40F its starts immediately the next morning. Based on my home mechanic knowledge it just seems like fuel pressure issue to me. I need to see if VCDS can monitor the fuel pressure after sitting. BTW I did have the software "fix" back in July??

dieselpony · September 19th, 2017, 19:25

I have the same issue with my 2015 more and more often, only when it's been sitting for 8+ hours. Makes me worry a little bit about the coming winter and super cold starts. I'm going to do some experimenting with only touching the push button once, then waiting a bit, and pushing again. Maybe in-tank fuel pump will build pressure or something. I'm guessing it's not cold enough for glow plugs to function yet, but not sure? Garage stays more than 60F overnight.

sands80 · September 19th, 2017, 20:06

Starting the TDI in the winter is a non- issue, the long starts only seem to affect me in the summer, after it sits for 8 hours+.