temp gage going to hot and glow plug coming on after starting

[dyoungen]

Greetings again!! I have a 1985 Jetta N/A ?Diesel with a 5 speed. I haven't run the car in about 2 weeks as I"ve been waiting for some new headlights. I started the Jetta just to make sure everything was fine and after it started the temp gage went to full hot and the glow plug light started flashing after just about 30 seconds run time. The water tank on the fender wall is full and there is a solid stream of water coming into the tank. Any ideas? Also if it helps any, the Jetta starts fine without much cranking, just a few seconds.

[cyrus #1]

It sounds to me like there is an electrical problem.  Either a break or a short in the sensor wiring.  It does seem odd they would both happen at the same time though. 

[dyoungen]

I understand what your saying. The glow plug light is the light in the temprature gage, isn't it? Just wanted to make sure. Is there anything other than where they are to connect them?

[Vincent Waldon]

The glow plug light is the light in the temprature gage, isn't it

Actually no... hmmmm.

The glow plug light is yellow... temperature overheat / low coolant is red.

What colour is the light you're seeing?  If the answer is "red" then it now makes sense... defective wiring/sensor causing the car to think it's overheating:  gauge goes up, red overheat light goes on.

[rodpaslow]

I agree, check wiring.  I forget which happens, but if the temp gauge is either grounded or open it will go to full hot or cold, I don't remember which (it's likely if the wiring is open it goes to full hot).  I would try just turning the key on when you know the engine is cold and see if it goes to full hot within a minute or two of turning the key on.  If this is the case you have a wiring issue.

[dyoungen]

Ok, problem solved. I thought I was looking at the glow plug light (yellow) when in fact I was looking at the low coolant light(red). I checked the coolant tank and it was a little low. I also found out the radiator has a small leak which let some of the coolant out after adding some coolant the light stayed off(red). Now I"m looking at a radiator replacement. Where is the best place to get a radiator or just get one from the local auto parts store, OReilly is who I"m talking about.

                Thanks for everybodys help!!!