Engine running temp help please.

[webbie]

Ok guys, hope you can help me out with this one. I have a 1UZ in a Toyota Surf (Hilux) and i'm on the home stretch of the project until this little hicup.

Here's the story:

I am running 2 11" fans as pushers with a custom shroud covering the top 2/3 of the std diesel rad (until x-mem at front) and all air goes through rad. This rad was pro cleaned at Red Devil.

I have a aftermarket water temp gauge/sensor located in aluminium housing of water outlet and is reading correctly ie 100degC in boiling water.

This is what baffles me,

1. On start up, car will hit 90-92degC before it idles down (which to me should be around 80-82?) , then will continue to rise till about 96-97deg and will stop there regardless of driving conditions, hard driving soft driving, slow traffic, highway speed......

2. After driving for 20-30 mins (and reading 96-97deg), the bottom of the rad is still cool (can leave hand resting on it)

I have put 2 different thermostats in it (new), new coolant, dist water/water wetter, spaced back of bonnet up.

I am open to all opinions. I am fully aware that there could not be enough air flow ect, but why do the above happen?

Is it possible the water pump not flowing enough? Air pockets in system? Not enough air flow? :???:

ANY feedback would be greatly appreciated.

Thanks guys.

 

[Peewee]

If the bottom of the radiator is still cool, then it sounds like the radiator is blocked.

If you didn't flush the motor prior to starting it, all the gunk from inside it would have ended up in the radiator.

 

[webbie]

Am I correct in thinking that this gunk is soft and the radiator can be flushed with a hose or should it be taken out for pro flush?

Good point, wouldn't have given it a second thought. But the engine was running in the 1/2 cut when I got it. I'll take the rad out tonight and have a look and let you know.

Any other suggestions?

Cheers.

 

[Peewee]

Professional flush only.
They remove the top tank, and check all the cores.

My rad was only 10% blocked, yet it was enough to make it over heat like crazy on the dyno (was OK on the street according to the temp guage).

Got the rad flushed, and it was fine from then on on the dyno.