Rav4.3 Xa3 2.2 D-Cat Enginge Warm-Up

[proxonic]

Guys,

Two days ago in the morning my enginge started to have longer warm-up time. It was cold - something about 0 C.

The temperature indicator went up as usual but it stopped at level about 20% (saying min-max is 0-100%). It was hanging in this position for 15, 20 minutes and then it went up to the normal temperature - at level about 55% or so.

Since then it happened already 3 times - every time in the morning, but afternoon the pointer is stopping at 20% but for a shorter time. Afternoon was about 10 C outside.

When it happened for the first time - when the enginge temperature was too low when it should be already normal - the engine's rpm were going up to 1200 everytime when i stopped the car and switched to neutral.

Right now, even when the engine temperature is too low, the rpms are normal.

Is it normal? I doubt. Damaged thermostat?

thanks for any advises.

Tomek

[anchorman]

Hi Tomek

This 2.2 FHV engine is one of the later generation common rail diesels with a very high thermal efficiency. It means that most of the heat it produces is turned into energy and is directed straight out through the exhaust. By comparison, the current VVTi gasoline engine has a low thermal efficiency and absorbs a good proportion of the heat. It warms up very quickly.

As the ambient temperature falls, the warm up time increases exponentially and this can be seen in the difference between 0 Celcius and 10 Celcius. There isn't much you can do about it - even the thermostat and radiator design has been optimised to give the fastest warm up. Your heater is even fitted with a small electric heater in the intake which serves to reduce the chill of the incoming air (although in reality it cannot generate any noticeable heat). I think you will find that the idle speed increase is a function of the ECU responding to the demand from the climate control. If you turn the system off when your engine has got to the 20% mark you should find that the engine drops back to idle. There is a combustion heater option for very cold climates. You could enquire to Toyota GMBH to see if it is a viable option. Other than that you are stuck with a long warm up period and it will get worse when the temperature fall to sub zero.

PTC heater;

PTC heater.pdf

Power heater option;

Power heater.pdf

[vivianM]

My T180 has always taken a long time to warm up even in summer and much longer on cold winter days - for the temp gauge to reach the correct position - but the heater does produce warm air quite quickly. It can take about 10 miles before the temp. gauge is at the running position, I do try not to use revs over 2000 until the engine warms up - as the other post about being sluggist in cold weather there is no sign of that but I do notice the revs are higher (on tick over) until it has well warmed up and it can be a bit of a nuisance in traffic.

Guy

[proxonic]

Guys,

Thanks to both of you for the explanations.

It is very helpfull.

:)

Cheers

Tomek