Glow Plug problem or coolant sensor???

[VDubLover]

Hey friends...I have an 02 TDI Beetle and it has become increasingly 'rough' to start (in temps ranging from 75 and below!). My glow plug 'coil' goes on for just a second (doesn't make a difference what the OAT is..) prior to starting. When starting the engine, it takes a couple of seconds of cranking prior to engaging. The blue coolant light will stay on for a few minutes (also doesn't make a difference what the OAT is). Help! Is this and indication of faulty glow plugs or a coolant sensor?? Another thing to note (not sure if this is related or not) is that my fuel milage has gone down considerably...I've gone about 100 miles on a hlaf tank!!Unfortunately, the car is in ND and HOURS from any dealer. I would appreciate any help!!!

[MyOtherRidesAVette]

I'm not a dieslel geek, but the coolant blue light should stay on. Until the engine reaches operating temperature. 6-10 minutes is probably the norm. I think I timed mine at 8 minutes after not being started all night. So it is doubtful the coolant sensor is related to your issue.

M.

[h_2_o]

the blue coolant light should stay on for a couple minutes. IIRC it is supposed to mean not to rev your engine above 2k rpms until it is at operating temp or something like that. now why it is cranking over before start could be a zillion things but the blue light is ok.

[Smileybug]

Do you have a check engine light on? How many miles on the car? Has the fuel filter been changed recently?

[janitz]

As I recall from when I had a problem (for two years due to poor service from the dealer) with my glow plug harness that would kill a plug, the check engine light will be on if any of the glow plugs fails.

It sounds like you've got a weak battery, or your starter is the issue.

How old is the battery? Tested recently?

[VDubLover]

Thanks for the replies...it has about 125,000 miles, a 1yr old battery, and hasn't had the fuel filter replaced recently...check engine light went on once, but by the time I got to the auto parts store to plug it in, the light had gone out and it hasn't come back on since.