[TR] Explain This Overheating

[Kinderlehrer]

Hi Bill, 
Don't know the state of your engine, but one thing that made a big
difference in my car was removing the petcock at the rear of the engine,
cleaning out all the scale inside the block that I could, and then flushing
the block. I also don't run more than 20% antifreeze as I've heard from this
list that it really isn't very good at cooling.

Since you have a puller electric fan, you don't have a mechanical fan which
means that you are pretty dependent on that electric fan, so the question
is, are you sure it is coming on like it's supposed to? 

Sorry, don't know why it is overheating on the downhill run. I suppose it
has to do with what the RPM's are and how hard the engine is working to slow
you down.

Bob


-----Original Message-----
From: triumphs-bounces at autox.team.net
[mailto:triumphs-bounces at autox.team.net] On Behalf Of William Brewer
Sent: Wednesday, March 13, 2013 10:19 AM
To: Triumphs
Subject: [TR] Explain This Overheating

     So I've begun driving the TR3 to work again. It has been in the 80's
during the day in Mojave. It is pretty brisk at 0600 at the mile high
elevation that I live at.
     The temperature gauge in the TR3 has lost the ether and is getting sent
in to be rebuilt asap.
     So yesterday I am
driving home. The TR runs like a freight train. I coasted down about 1/2
mile and downhill and stopped outside my garage. While the garage door is
opening the car overheats and steam comes out.
     I topped off the coolant. Later
that evening I let my daughter drive the TR with me in the car with her. We
are tooling around the hills at low speeds, under 35 mph. We coast down
about a mile of downhill and stop at a stop sign. I begin smelling hot
coolant again. It is like it is taunting me.
     My radiator was rebuilt about 12
years ago without a crank hole.
     I have blocked off the water pump bypass with a brass plug with a 1/8"
hole drilled in it to prevent vacuum lock.
    
I have an electric fan (puller, not pusher) that comes on at about 190.
    
Tonight I am going to use a Prestone radiator flush and refill with fresh
coolant and distilled water 50/50 mix.
     With the coolant out I am going to
pour water in the top to see how fast it sloshes out the bottom hose hole to
see if the radiator appears blocked..

     I only use distilled water and
coolant in my radiator.
     Last year I put on a new Moss radiator cap and a new 185 thermostat and
put on all new hoses.
     My question is, why does it
overheat after a long downhill? I could see it overheating after a long
uphill.
     Gotta get the temp gauge fixed. I meant to do it when the cold weather
arrived.

      -Bill in Tehachapi