Running 1UZ vvti off '98 celsior, ~60k' s on it. Timing stuff replaced (belt and everything), water pump also replaced with toyota original unit just incase. Old WP was fine though.
Radiator is brand new aluminum aftermarket unit, the biggest one I could fit. Sized about 600x450x60mm. Using original Celsior hydro fan with no shroud. Temp sensor for the hydro fan control is installed into a metal pipe that connects bottom radiator outlet to thermostat housing. The sensor itself is very close to the radiator outlet.
Thermostat: haven't yet replaced it. Using red coolant.
The problem is: I was driving ~700km the other day and it was fine all the way. Diff ratio is 4.1, there's ~3500 RPM @ 140kph. Gauge temp sensor was consistently showing the normal temp.
On the next day however I suddenly noted that in the very same driving conditions, the temperature reading suddenly went up. I slowed down to ~100kph and it went back to normal. Tried that several times, and each time I had to slow down to bring the temp back to normal.
Later on I had to spend ~4 hours in a stand still traffic jam and the temp was ok.
It's the first time for ~6 month of running the engine in my conversion project when I experience this problem.
What I plan to do is replacing the thermostat and bleeding the system properly. Maybe I can have some advice here? Previously, I just filled the radiator, open its cap, filled the overflow reservoir until it drains to the radiator and that's it. Only checked the reservoir level a couple times just to find it at previous position.
I've just read somewhere on the web that I must get the engine as cold as possible, and fill it with coolant thru the hole on the throttle body, having its bolt (inverted hex one) unscrewed. (my engine is like that of 98-00 LS400, and I've read that these engines are bled through the throttle body bolt). Is it true that otherwise the system will not be bleeded properly? Does it also mean that if I never done this procedure I was always driving with some air in my coolant system, but somehow I never seen overheating?
Radiator is brand new aluminum aftermarket unit, the biggest one I could fit. Sized about 600x450x60mm. Using original Celsior hydro fan with no shroud. Temp sensor for the hydro fan control is installed into a metal pipe that connects bottom radiator outlet to thermostat housing. The sensor itself is very close to the radiator outlet.
Thermostat: haven't yet replaced it. Using red coolant.
The problem is: I was driving ~700km the other day and it was fine all the way. Diff ratio is 4.1, there's ~3500 RPM @ 140kph. Gauge temp sensor was consistently showing the normal temp.
On the next day however I suddenly noted that in the very same driving conditions, the temperature reading suddenly went up. I slowed down to ~100kph and it went back to normal. Tried that several times, and each time I had to slow down to bring the temp back to normal.
Later on I had to spend ~4 hours in a stand still traffic jam and the temp was ok.
It's the first time for ~6 month of running the engine in my conversion project when I experience this problem.
What I plan to do is replacing the thermostat and bleeding the system properly. Maybe I can have some advice here? Previously, I just filled the radiator, open its cap, filled the overflow reservoir until it drains to the radiator and that's it. Only checked the reservoir level a couple times just to find it at previous position.
I've just read somewhere on the web that I must get the engine as cold as possible, and fill it with coolant thru the hole on the throttle body, having its bolt (inverted hex one) unscrewed. (my engine is like that of 98-00 LS400, and I've read that these engines are bled through the throttle body bolt). Is it true that otherwise the system will not be bleeded properly? Does it also mean that if I never done this procedure I was always driving with some air in my coolant system, but somehow I never seen overheating?
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