Cold weather start...

oilhammer said:

You may have to crank it a bit and hold the starter as first one, then two, then finally three cylinders start hitting and it can run on its own... the fourth will kick in shortly thereafter.

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Is there something in the '03s that prevents this from working? Even though I hold the key in the start position, the starter disengages as soon as the first cylinder fires. At single digit temps, this isn't enough for the engine to "catch." I have to cycle the key off before it will let me crank again.

On a 8 deg morning, I let it preglow twice before cranking, but I had to try 8 - 10 times before it started. Cranking speed is normal, the battery was replaced just a couple of months ago, and a new Bosch starter was put on a couple of years ago. On a couple of other mornings that were colder, it wouldn't start at all, other than a cylinder firing and the starter disengaging.

Sounds like something is up with your car . When it was below zero earlier this week, I started my 2000 ALH Beetle, and I had to run the starter for over 10 seconds before it got the engine running enough.

Yeah, it definitely has some cold weather starting issues. I think it would start, though, if I could keep cranking it, but something (ECU?) cuts off the starter at the first hint of firing.
Hopefully the arctic blast won't come back, and I won't have to worry about it until next winter. When the temps are double (or triple) digits, it starts easily.

There's actually nothing in the car's design or ECU programming to cut off the starter... MUCH more likely the starter's over-run clutch is wearing out. Diesels are hard on starters and the over-run clutch is a bit of a wear item, particularly if it's an off-market starter (dunno what brand your starter is, of course).

Follow up: It was -7 and below zero for 1-1/2 days. She started up both days. Cycled the glow plugs 3 times and cranked until she fired. I did use fuel conditioner to keep it from gelling. She didn't like the extreme cold ( Who does ? lol ) , and my fuel mileage fell to 50 MPG, but warmer better days ahead !!! THANK YOU everyone for your advice !!! It really helped !!! The " Menace "

its been warm here since sunday, a string of about 60dg days.
get some garage work done.

I've had to leave a trickle charger on over night as the zero start I installed isn't working. I don't think I have it low enough. Anyway, I have had to use a booster pack and cycle a few times to get the car going the past couple days. How much damage do you think happens to the starter if you keep cranking until the car starts? Seems like after the car is warm, the starter seems to go for a quick second longer after the vehicle starts.

On 02 and 03 ALH TDIs, they have a solid state GP relay and the GPs stay on for several seconds after the curly GP light goes out. There is no need to cycle the GPs more than once.

Older TDIs with the 2-wire GP harness have a mechanical GP relay and the GPs supposedly turn off when the light goes out and you can hear the relay click. 02 and 03 ALH TDIs won't make any click sound due to the solid state GP relay (has no moving parts). 02 and 03 ALH TDIs have a 4-wire GP harness.

The technique I used in my 02 Golf TDI is to preglow with the car door open so the interior lights are on. I watch the interior lights dim slightly during preglow so that I know the GPs are definitely on and working. I watch for the interior lights to brighten back up again several seconds after the GP light goes out. Then I hit the starter as soon as I see the interior lights brighten up which tells me the GPs just turned off. I found I always got the best cold starts this way in subzero temps. The GPs are good and hot and you are cranking the engine without the GP load on the battery. I found I always got slower cranks when I hit the starter as soon as the GP light went out because the GP load is on the battery in addition to the starter and everything else. Carefully watching and waiting for the GPs to finally turn off before hitting the starter always worked better in the bitter cold. The curly GP light on the dash doesn't tell whole story and the behavior is different from older TDIs in 02 and 03 ALH TDIs.


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Vince Waldon said:

There's actually nothing in the car's design or ECU programming to cut off the starter... MUCH more likely the starter's over-run clutch is wearing out. Diesels are hard on starters and the over-run clutch is a bit of a wear item, particularly if it's an off-market starter (dunno what brand your starter is, of course).

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You hit the nail on the head here, Vince. The overrun clutch finally gave up the ghost this spring. This was an off-market starter, but it lasted two years. It had replaced a genuine Bosch reman unit that did the same thing in only five months.


I still have the Bosch unit, which looks like new. Does anyone know where I can get a replacement overrun clutch for it? It would be nice to have a spare on hand.