Re: Overheating problem

[TRedGLX@aol.com]

In a message dated 9/6/00 8:01:15 PM Central Daylight Time, VWNobby@aol.com 
writes:

<< I own a 97 Jetta GLX with 56,000 miles on it. About 3 months ago or so I 
 noticed that the temperature gauge (coolant temp.) started to go past the 
 center marker. At first it would only go a few degrees past the center mark. 
 But lately it actually reaches up to 230 which is 3/4 of the way through. 
 Usually I open the vents and have the heater on full blast to cool it down 
to 
 the center point. But obviously that's a temporary fix. Today I noticed that 
 the gauge reached about 220 then dropped to the center and then eventually 
 went past 225, all within a 30 minute drive. Even at highway speed I have 
 this problem. I have checked the coolant level and it is fine. Both the fans 
 are constantly working, so I am pretty sure that isn't the problem. I 
 installed a G-Chip about 3 months ago and I am wondering if that may be part 
 of the problem (I would think that since there is more power coming from the 
 engine it would tend to run hotter). Other possibilities that crossed my 
mind 
 were the thermostat or the coolant pump, but how can I pin point the trouble 
 spot. If anyone has run into a similar problem, please let me know. Any help 
 would be greatly appreciated, I'm sure this problem can only be detrimental 
 to the life of my car. Thanks in advance. >>


When did you have the coolant flushed/changed last? Old, weak antifreeze can 
have a detrimental effect on engine cooling. I noticed no increase in engine 
oil or coolant temps when I added the G-chip, so I doubt that's the cause. 
Heavier oil (15w-50, 20w-50, etc.) will raise the coolant temp in addition to 
the increased oil temp, heavier oil tends to hold heat longer than lighter 
oils. Just a couple avenues to explore....

David Steele
1998 JettaGLX TRed
1988 Jetta Coupe Atlas Gray
1987 Jetta Marine Blue