GOLFMK8
GOLFMK7
GOLFMK6
GOLFMKV

2015 Golf R - Strange start issues - Any suggestions?

ilikevenice

New member
Location
Florida
Car(s)
2015 Golf R
Hello,
I have a 2015 Golf R w/ 90K miles on it.
Everything seems to run fine, and usually it starts right away (push button).
However, if I drive it hard (high RPMs, Race mode, etc.), when I eventually turn it off and after an hour I try to restart it, I have to press the button 3 to 4 times before it starts and runs properly.
On the first attempt, it starts, but then it stalls.
On the second attempt it doesn't start at all, on the 3rd or 4th is starts normally, idles fine and drives fine.
Has anybody experienced a similar issue?
Any suggestion will be be greatly appreciated.
 

Vwpaul

New member
Location
Las Vegas
Car(s)
16 Golf R
LPFP losing prime/failing? Sounds like the old MK4 hot start issue. By the 3rd or 4th start, the prime is restored and the failing pump can keep up the supply. Shot in the dark without hearing or seeing the car.
 

Al_in_Philly

Drag Racing Champion
Location
Philadelphia USA
My guess is that what's going on has to do with your underhood air temp. You say that this happens only after you run the car hard and then wait about an hour to restart the car. During that time, the underhood temp rises, as there is no air circulating, outside of convection, but the engine and radiator are still radiating heat under the hood. All of this can cause a disjoint between what the ECU calculates the air coming into the engine to be, and what it actually is--at least until the air in the airbox has been depleted and relpaced with air of the temperature which the ECU thinks it's getting. Remember that our cars don't have air-mass-flow sensors, as with earlier FI systems, but rely on multiple temperature sensors and calculated air-flow maps in the ECU. FWIW, my 2015 (with far fewer miles) exhibits this same behavior every once in a while, when it sits a bit after a good thrashing. I hope that helps.
 
Last edited:

jimlloyd40

Autocross Champion
Location
Phoenix
Car(s)
2018 SE DSG
My guess is that what's going on has to do with your underhood air temp. You say that this happens only after you run the car hard and then wait about an hour to restart the car. During that time, the underhood temp rises, as there is no air circulating, outside of convection, but the engine and radiator are still radiating heat under the hood. All of this can cause a disjoint between what the ECU calculates the air coming into the engine to be, and what it actually is--at least until the air in the airbox has been depleted and relpaced with air of the temperature which the ECU thinks it's getting. Remember that our cars don't have air-mass-flow sensors, as with earlier FI systems, but rely on multiple temperature sensors and air-flow maps in the ECU. FWIW, my car (with far fewer miles) exhibits this same behavior every once in a while. I hope that helps.
He also said that after running it hard he drives for an hour before shutting it off.
 

ilikevenice

New member
Location
Florida
Car(s)
2015 Golf R
Thank you guys for your replies and suggestions. I'm going through a couple of full tanks with LUCAS additive to clean the fuel system.
I will let you know if makes any difference.
Just trying the cheapest options first... ; )
 

Thattorquetho

New member
Location
Barrow-in-Furness
Car(s)
Golf R MK7
Hello,
I have a 2015 Golf R w/ 90K miles on it.
Everything seems to run fine, and usually it starts right away (push button).
However, if I drive it hard (high RPMs, Race mode, etc.), when I eventually turn it off and after an hour I try to restart it, I have to press the button 3 to 4 times before it starts and runs properly.
On the first attempt, it starts, but then it stalls.
On the second attempt it doesn't start at all, on the 3rd or 4th is starts normally, idles fine and drives fine.
Has anybody experienced a similar issue?
Any suggestion will be be greatly appreciated.
Before I bought my golf I had a vw tiguan allspace and I had exactly the same issue with that, first time start up, spot on but the longer I drove it, the harder it was to start, by the end of the day I had to fiddle with the button and press it around 10 maybe 15 times before it would start, I took it back to vw and they sorted it, apparently it was something in the software, just food for thought.
 
Top