Corolla temp - overheating

Greetings

The puzzle of why the car was overheating has been solved.

It was not clogged radiator (Internal/external), dud pump, leaks,
thermostat, coolant type or level, radiator pump, EGR valve, belt
tension or timing.

It was confirmed (or actually disproved) during a 4 hour freeway run
with a multimeter and thermocouple insitu. Despite the guage showing
red zone and even higher than red super hot, the coolant temp never got
higher than 92 degrees celcius (+/- 3 %).

Travelling with the needle in the red for over 120 kilometres meant
that either Toyota build bomb proof cars, or, the temp sender is
stuffed.

Thanks to all that offered ideas.

Cheers

Hammo

On Thu, 24 Aug 2006 07:13:55 -0700, hammo wrote:
[color=blue]
> Greetings
>
> The puzzle of why the car was overheating has been solved.
>
> It was not clogged radiator (Internal/external), dud pump, leaks,
> thermostat, coolant type or level, radiator pump, EGR valve, belt
> tension or timing.
>
> It was confirmed (or actually disproved) during a 4 hour freeway run
> with a multimeter and thermocouple insitu. Despite the guage showing
> red zone and even higher than red super hot, the coolant temp never got
> higher than 92 degrees celcius (+/- 3 %).
>
> Travelling with the needle in the red for over 120 kilometres meant
> that either Toyota build bomb proof cars, or, the temp sender is
> stuffed.
>
> Thanks to all that offered ideas.
>
> Cheers
>
> Hammo[/color]


The question: Were you measuring at the same point that the temp gauge
sender is?

Hachiroku wrote:
[color=blue]
> The question: Were you measuring at the same point that the temp gauge
> sender is?[/color]

The answer:

No, I was measuring the coolant temp a short distance from the position
of the temp sender unit. The absence of steam, nil loss of coolant and
that the gauge was showing the temperature was in the red when the
thermo couple showed it was at 70-75 C, I am not concerned in the
minnimal difference in positioning. The flow rate of the coolant at
engine speeds of 3000 rpm plus suggests that the minimal difference in
location is also negligable.

Are you suggesting that the problem is not due to the sender unit?

Cheers

Hammo