[Supras] Thermostat Question Again!

[Charismatisch at aol.com]

Hi there guys and gals,
 
I am sorry to have triggered-off such an argument with my question, however  
my problem still remains the same.
 
The radiator is brand new, so are all the gaskets (inclusive valve shafts  
and HG). I did a full oil-change and coolant-change with the HG and replaced the 
 plugs. The whole fan and clutch is also brand new.
 
If I stay in town traffic, the temp gauge never goes above the  halfway level 
and the car runs beautifully and shows me a full radiator once it  cools down 
and I am able to open the rad.cap. The heating blows hot after about  a 
minute already, indicating to me that the thermo is functional at the  beginning.
 
Once I take the car onto the Autobahn at 150+ mph and as long as it is  being 
cooled by the air from the front, the temp stays ok. When I come off the  
Autobahn and reach the first stop sign, the temp slowly climbs into the red and  
comes back down a little when I drive off again. When I reach home, the water 
in  the expansion tank is gurgling. After spewing a little, the rad. shows me 
too  little water.
 
Also, the main rubber pipe to the rad. at the top is often warm/hot and has  
some air in it, whereas the bottom rubber pipe from the rad. to the engine is  
cold or cooler. This would seem to indicate, that the flow of the water is  
getting partially 'stuck' or 'slowed-down' somewhere, which may mean, that  the 
thermo is not functioning fully and creates a kind of 'tailback' or  
'congestion' in the system and is not allowing it to flow fast enough when the  engine 
is under duress.
 
As a layman I would think that the thermo is closing fully when cold (hence  
the heating working soon and well at first), but not opening fully when the  
coolant/water mixture is hot. This wouldn't become apparent at slow speeds/town 
 traffic, but under strain at 150 mph the thru-flow would not be sufficient 
once  the car comes to a hot standstill.
 
Your comments please??.
 
Derek, 88T Automatic.
 
 
 
 



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