[TR] TR4A overheating

[Randall]

> I start the engine and it warms up quickly and within 2-3 minutes the
> temperature gauge is on "H". The top of the radiator is hot. the down tube is
> cool so the thermostatic switch won't close.

How hot?  Is there any chance your temp gauge is reading way high and the engine isn't really overheated?  It can be hard to tell the difference between 170F and 200F just by resting your hand on it.  But at 170F you would expect the thermostat to stay closed and block flow through the radiator.  The upper tank still gets hot from conduction, though.

If the top is definitely getting over 180F and the bottom is still cool without the fan running, then you clearly have a circulation problem.  Could be a clogged radiator; but they rarely clog up all at once so I would be double-checking other things.

Randall