[Vwdiesel] A tale of two coolants or my life and times as a glycol-holic!

Hayden Chasteen dieseltdi at earthlink.net
Fri Mar 26 08:57:19 EST 2004


Ever since I put my Caddy back on the road, I have been concerned with 
the temperature at which it runs.  Not only was the water temp too high 
as far as I was concerned but also the oil temp.  At times water temps 
would rise to just 1 white notch below the red and oil temps would 
reach 220+ degrees F. Part of this heating I attributed to the turbo 
engine running hotter but it was too hot for me.   Now you have to 
understand that I have replaced the water pump, the thermostat (yes I 
checked it in hot water before I installed it and I drilled two small 
relief holes), the radiator (with a genuine copper one with metal 
intakes), most of the hoses, put in a two speed fan and fan switch 
(with after run) and  yet the  "heating episodes" continued.  I 
mentioned this in frustration to my son (the "professional" 
mechanic...thank God he has a job and his own apartment now!) and he 
asked me which coolant I was using - red or green.  Well, being the 
convenience enthusiast that I am, I had decided to use the red coolant 
so that I didn't have to change it so often.  "Well", he almost 
sarcastically says, "that is your problem. for what ever reason, early 
water cooled VWs don't seem to cool as well with the red.  My Scirocco 
and formerly owned Corrado both ran hot with red coolant.  Switch back 
to green and your heating problem will go away!"  Well not being one to 
question the word of a professional, I flushed the system AGAIN and 
used the green coolant.  Guess what?  The car now runs at the correct 
temp, it never goes above the first mark above the middle and doesn't 
even reach that unless I really stand on it for a while.  And the oil 
temps that used to reach 220+ now rarely go above 190!  SOOOO anyone 
else noticed this strange state of events?  As I pondered how my son 
could actually be so smart, I remembered that when I put the 1.9TD in 
to my old 85 Jetta, I used the red coolant in it also and it ran hotter 
that I liked.  I just put it off at that time to the larger turbo 
charged engine.  Any chemists in the group could maybe explain this?  
BTW,  I used the same mixture of green and red with water in the 
radiators (50/50 or very close) so the variable is only red verses 
green.  Talk amongst yourselves and make comment.  At this point I am 
baffled.  Hayden

Visit my website at  www.home.earthlink.net/~dieseltdi
Proud owner of:
2004 Passat TDI GLS, 2.0l, 16 valve, 134 HP, 247 lbs/ft of torque, Blue 
Graphite, Grey leather interior, now being built and on the way to me!  
  :^)
1998 Jetta TDI (Wetterauer Chipset, 2 1/2" exhaust, K&N Filter, propane 
dual fuel system, 109K+ miles, and running biodiesel)
1981 Rabbit Pickup ( with a freshly rebuilt turbo engine), Will burn 
biodiesel and WVO with a propane injection system.
One, yet to be finished, Caddy trailer (the back end of the truck that 
gave its life to my just completed Rabbit Pickup).
And many, many, many VWs; from a 1946 Beetle (11 Beetles total), to 
Vans (5), Rabbits (3), Karmen Ghia (1), Jettas (5), Passat (1), Dasher 
(1), New Beetle (1), and Rabbit Pickups (3) most now gone but not 
forgotten.



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