Glow Plug actuation question

[whizznbyu]

In a 6 speed manual TDI, does the glow plug start heating once the ignition is turned on, or does it get current only after the clutch AND the "engine start stop" button are depressed?

 

[whizznbyu]

Reason for asking is the battery died the morning of a cold snap. I was fortunately parked at an incline and got the car running. Engine ran instantly when I turned the key on AFTER the car was rolling, put it in gear and released the clutch. I thought I'd have issues with the cold fuel and getting the car started.

 

[oilhammer]

The preglow is active when the glow lamp is lit, and if you do nothing after it goes out, the preglow may continue for a few seconds longer. Then the glow plugs get switched off during cranking, and once the engine is started, they come back on for afterglow, and depending on coolant temp and RPM, may be active for a few minutes after the engine is running.

 

[TurboABA]

What? It sounds like you "bump" started the vehicle, so it wasn't the glow plugs that helped you start it.... it was the mechanical RPM induced by you rolling downhill and engaging the gear.

With a '15, you should be changing the battery if you haven't already... they don't last for ever!

 

[whizznbyu]

What? It sounds like you "bump" started the vehicle, so it wasn't the glow plugs that helped you start it.... it was the mechanical RPM induced by you rolling downhill and engaging the gear.

With a '15, you should be changing the battery if you haven't already... they don't last for ever!

Bought the car 2019 supposedly with a new battery. Maybe it is a reconditioned battery.

 

[TurboABA]

Look at it and find a date on it.

 

[thundershorts]

new batteries from vw are made by varta and are excellent, forget buying a cheaper battery

 

[whizznbyu]

Many mechanics swear by Interstate. Anyone else have a "best brand" recommendation?

 

[oilhammer]

Interstate (JCI) went in the toilet some years back. That's why we switched here.

VAG OEM and replacement batteries are very good. They can be supplied by several companies. Entertec, Varta, and I even had a 2019 Jetta here with an Exide battery under the hood from the factory.

Oddly enough, Varta was part of JCI, but that name has been changed to Clarios now.

In any event, the OEM has a specific datasheet it must meet, and VAG's requirements are as good or better than some, so the dealer stuff is good. And add to the fact that they are competitive on price, all the better.

They are a common case size battery, so if you absolutely need to, you can find one that will work almost anywhere.