so i got a 2000 jetta tdi, I'm an aircraft mechanic and have little knowledge of cars, I have been narrowing it down with my troubleshooting skills as best I can

was starting fine all last winter and this summer, now that it's starting to get cold I've had two mornings where it failed to start and drained the battery in the process of trying and had to get jumped.

my thought process went as follows:
1) bad battery, not holding a charge. OR something grounding and sucking juice out of battery.. tested battery, it is in perfect shape (I did however notice it's a bit smaller than what would be ideal for the diesel, I'm thinking that's why it dies so fast when i repeatedly try to start it)... Alternator IS charging.
2) fuel issue, the slow starting may be a fuel issue i thought, I know the filter should be changed soon and I've ordered a new one already to do that, but in the mean time it's still firing up when it's warm enough so I don't think it's 100% that.
3) it's just too cold, get a block heater for it. I will probably do this anyway, but it started on much colder days all last year.. this is a new problem.
4) Glow plugs. I was thinking maybe they're not getting hot enough fast enough to warm up cylinder/ignite the fuel air mixture.. checked online for info. came up with several sites saying they should be resistance checked between ground and them and be between .5 and 1.2 ohms and no more than .2 ohms difference on any single one compared to the others.. so i got my meter out and measured #1 and #2 cylinder at 0.00-0.01 ohms, and cylinder #3 was at almost 3.5 ohms... (did not measure #4 because I will replace them all at once)


So at this point I'm wondering if anyone has any experience with this type of thing and if the new glow plugs will fix this or if there's other things I should check beyond getting a bigger battery/fuel filter or if glow plugs should do the trick


thanks for any tips/ideas!

Glow plugs or injectors. Once you get it started when it is cold does it smoke at all?

bit of a cloud out the exhaust when it starts up, but it doesn't smoke continuously

I'm not as familiar with small diesels as i am the larger ones but any white smoke on a cold start is a fuel system issue unless it is really cold. Glow plugs should be cheap and as you said they didn't ohm out well.

I had this issue with my tdi last winter, it was the glow plugs and the wire that feeds them all. Most of the time the wire will get brittle and break on the inside, causing issues on cold starts. Just make sure to replace the plugs with the same brand of plug you currently have and get a new wire.

Good place to get them is Germanautoparts.com
they have factory quality parts at great prices, and if you live on the east coast shipping is fast.

it's not white, so hopefully that rules injectors/fuel out



awesome, did you replace the relay too or just the harness and plugs?

Just the harness and plugs, the relays tend to last a very long time till they break and thats not as common. Hell I've got almost 400k on my relay system and it's still fine haha

This post was edited by TheBroodwich on Oct 25 2014 05:06pm

395k on mine 480 on the rest of the car minus the transmission and engine.. i love this car lol


appreciate the help man! I've been scratching my head all week I feel like we've got it figured out now finally

Miles or km??

And anytime man, I love mine too haha

km! not as bad i suppose