4KQ overheating light

[DQVT74A@prodigy.com ( CHANGLONG HUNG)]

Hi all, 

I have spend all night trying to find the FAQ page.  Could someone 
please send me the correct web address? TIA

Now the problem, My 4KQ dash overheating light blinks a few times 
whenever I am turning or on a climb.  I have checked the oil level 
and it is at the proper range.  Also, what is the average MPG on a 
'87 4KQ?  I am getting about 300miles per fill up which equals approx.
 20mpg.  It is driven both city and highway.  I have seen members 
with 30mpg.  Where do I start in order to achieve better MPG?  
Recently, I have changed the plugs, wires, air filter, intake 
manifold gasket(the cause of high idle speed).  What is next?  

Lastly, did anyone get in touch with the seller of '90 coupe quattro 
for $3800 in LI?  I have tried to contact the seller to no avail.  
That sounds like a great deal but maybe too good to be true.  

Sammy
'874KQ
'72 2002tii