problem with gen2 engine( keeps overheating)

[heigo2]

problem with gen2 engine

the engine is 2,0 turbo diesel,
here is the problem - the engine keeps overheating all the time, but it is not so that the water boils, the tempretaure rises to the level where the water almost starts to boil, but it doesn't, i asume the temp is about 80-90 degrees. the tempreture scale doesn't go to the red zone, which should be so called end of the engine, it stops on 2/3 and stays there for about 30-60 seconds and then trops to the "normal" posision...
i changed the sensor from the radiator, which should "tell" the fan to start work - no use...
then i changed the thermostate (valve) from the engine (hope you understand which part i mean) the part which closes or opens depended on the temo of the water - still nothing, it didnt help
then i took out the thermostate, now it takes a little bit longer before the temp scale rises to 2/3, and then it stayes there and dros again in about 1min...
it all concerns the time when i'm driving in city, about 50-60 km/h
but on the highway, speed about 90-110 km/h, everything is in order, when i trust the temperture scale....but when i stop the car and watch under the hook, the water is almost boiling..
and about the fan--they don't start to work, from 10 times, i 2 cases maybe..
PLEASE, could anyone tell me what could be the problem?
is it possible, that the radiator is congested?

[88 LE]

Originally posted by heigo2
and about the fan--they don't start to work, from 10 times, i 2 cases maybe.

Have you tried unplugging the ect (engine coolant temp) sensor while the car is running to see if the fans kick on?

The fans should also kick on when the a/c is on.

Hows the radiator cap? A bad one won't hold pressure.

Hows the water pump?

[heigo2]

yes, when i unplug the ect, the fans (there 2 fans on the radiator) start to work, (the car i own, doesn't have a/c )
the radiator cap is ok

about the water pump - i'm not sure, can't say by just looking, or i dont know what to look for there....
so, the problem might be caused by the water pump?
what should i watch there or how can i be sure that it is cause of the problem?

thanx

[Eqoistig]

/offtopic Hello "neighbour"! Nice to see other europeans around. :p

[Nico]

I have just had huge overheating problems with my Camry so I guess I understand your feeling ;-)
If it is the radiator, temperature should rise especially at high speed, on the motorway (faster than 60mph / 110 km/h), and the fan shouldn't really help to make the engine cooler. What I can say anyway is that replacing a radiator when a car is more than 10 years old is always a good thing (someone told me that before and I didn't believe it but now I do !).
Two other possible problems would be : bad radiator cap (not holding pressure), it often happens with Toyota's, so it is also a good thing to change anyway as it is very cheap (though I know Toyota parts in Europe aren't that cheap !!!) or it could also be the head gasket and probably also the cylinder head (which you could then find as used).
If you ever think the temperature might be wrong, you could also think of changing the temperature sending unit (this is also cheap and easy to change).

Is there any strange blue or white smoke coming from your exhaust pipe ? Do you think water and oil are mixed because then it would be the head gasket.
Let us know if you need any more help !

Good luck !

[toyrolla]

It could either be the water pump.

If the fluid is not circulating throughout the system, this would result in the car overheating. This could be due to either the water pump, radiator, or both.

I would recommend a "backflush" of your fluids. If there is some sort of blockage or corrosion, a backflush may help you that could be a problem too.

I'm not too familiar with the TD engine, but I would think that the cooling system should be similar to a non-diesel model.

To backflush the system, you would have to first drain the fluid, then flush water via the heater hose going towards the engine block. As you have the water flowing, turn on the car and turn the heater on to HIGH.

This allows the water to flow through the whole system in reverse, eventually out from the radiator.

If you see a lot of corrosion coming out, then you may have to change the radiator as well.

Of course, make sure you do this when the engine is cold.

I hope this helps you out.

Good luck with the car...