Overcooling on stock set up?

[jondee86]

If the thermostat is missing, or stuck open, the engine temp will "float"
according to engine effort and the ambient temp. That means ir will be
lower on cold days, and higher on warm days. Likewise, working the engine
will raise the temp.

It is the job of the thermostat to regulate the flow of coolant and maintain a
constant operating temp. If you had a working TRD thermostat, the engine
temp should hold steady at around 73 deg.

The thermostat is located inside an alloy casting on the intake side of the
engine, on the discharge side of the water pump.

Cheers... jondee86

[allencr]

What's it look like down the radiator opening when you rev 2-3000rpm?
When cold with no thermostat, there will be a huge flow, lots of churning rapids like, and if a thermostat is in place there will be little to no visible flow.
If coolant shoots out the opening when cold, there is no thermostat or it's stuck open AND the radiator's tubes are plugged.

[phill 92]

Right got this done ages ago just haven't been on the forum lately as I've been too busy.

I replaced the thermostat with a blueprint standard unit, the old one definitely was shot, put the new one and I still seem to have floating engine temps just a little bit higher than before.

Temperature goes up steadily to about 65ish, on a hot day it sits at 70 and with hard driving on a hot day it just about gets to 80. Is it possible I have a faulty water temp gauge? Or is there a chance the new unit has seized?

I'll give allencr's method a go and see what happens!

[jondee86]

Temperature sensor for the new gauge installed in the lower radiator
hose by any chance ??

Cheers... jondee86

[phill 92]

Nope temp sensor is on the top hose, but thanks for the suggestion i'm sure thats happened before!

[jondee86]

From what you are describing, it seems that your cooling system is
functioning normally. If the thermostat is working, by definition, it does
not open until the coolant in the engine reaches 80+/- deg, and the
thermostat then modulates to keep the engine at 80 deg.

It doesn't really matter how big your radiator is, or in what condition. The
engine temp hits 80 deg and stays there until the heat generated by the
engine exceeds the amount of heat the radiator can dissipate to the air.

The factory gauge sensor should be located to measure the temperature
of the coolant circulating around the engine. This should remain constant
under normal driving conditions. The aftermarket gauge is measuring the
temperature of the water being sent to the radiator, which will vary.

So try this... find a piece of cardboard and temporarily block off half of
your radiator i.e. the right half or the left half. Go for a drive and see how
the gauge reacts. Watch the factory gauge for signs of overheating !!!!

Cheers... jondee86