Engine temp?

Does anyone know what the normal operating temperature range for our mighty 1KZ-TE engine?
I suspect mine is running a little on the hot side... The first sign was when the air con cut out and the digi temp gauge had creep't up two bars above half way when going up a long hill on the highway but not pushing it harder than normal... This happened a few times so i thought i would install a engine temp gauge and see what the actual temperature was doing... During the winter the normal temperature was between 76 and 92 degrees celsius, then as the warmer summer days came round it's get's between 80 and 110, normal round town driving it will hang at about 90ish. When Sydney had those 40 degree days it was getting to 105 with out trying and i couldn't use the air con going up hills
I have checked all the normal things like coolant, thermostat, rad cap and have also flushed and changed coolant. Today i checked the viscous fan and that seemed to be working ok as well.

Could i have a partially blocked radiator?? Has any one experienced this?

Hi srburnsy,

I am a recent purchaser of an SC which is behaving wonderfully well so far. Prior to the SC I owned a Town Ace which had a habit of overheating. The principle cause of its problem was poor quality machining of the surface of the cylinder block coupled with a multi layer steel head gasket. There is not enough 'give' in such a gasket to seal properly against a poorly machined surface and the result was combustion pressure passing the gasket and into the coolant. The head was not cracked and neither was the block.

Assuming yours has not had the engine removed and the surface of the block machined roughly (as my Town Ace was), the problem may be in the area of small blockages in the radiator or the engine itself. I have the intention of putting radiator cleaner through mine to dissolve some of the rubbish which tends to accumulate everywhere, but particularly in the more confined spaces such as through the openings in the head gasket where holes in the castings may be quite large but the openings in the gasket itself may be only 4 or 5 millimetres in diameter.

There is one test that you could do - with the engine cool, remove the radiator cap, top up the coolant if it is down at all, start the engine, and let it idle for 15 minutes. If you have any bubbles appear in the coolant in that time, then there is indication of head gasket leakage for any one of a number of reasons. If there is head gasket leakage, be very careful not to allow the engine to overheat in any driving you do because you will only make the problem worse if you do. A 'watchdog' temperature gauge is a wise investment as it tells you the exact temperature of the engine and sounds an alarm if the temperature gets above what you feel is the proper maximum operating temperature.

You asked what that temperature should be. I don't rightly know, but above 105 would worry me. The normal operating temp of the townace (2C turbo diesel) was between 65 and 90 degrees. I would suggest you take that as a rough guide and be wary of allowing it to run too much over 100 degrees. I am not a qualified mechanic but have been doing mechanical work for the last 50 or so years and know more than the average joe. I spent 13 years in Papua New Guinea and was responsible for keep in 17 engines in running order as well as a million other things including teaching 35 periods of industrial arts each week.

A question from me - what engine is fitted to yours and is there just one radiator mounted in front of the engine or does yours have a second radiator laying almost flat down in the space between the main radiator and the front bumper bar with the air con condenser laying above and an electric fan above that?

Feel free to ask if you think I can be of some assistance. Richard.

Hi Richard, thanks for your reply mate.
Mine is the 1kz-te TDI 3lt engine with two radiators, one in front and the other laying flat with the air con condenser. From what i've found out the normal temp range should be between 70 and 90 and mine seems to be from 85 and 110 It happily stays around 90-95 easy driving around town but if i push her hard on the highway or going up hill for any distance she climb's above 100 and if she goes above 105 the air con automatically cuts out as she try's to keep cool. This has been going on for about 1year now and in that time i've been eliminating things such as replacing the thermostat, doing coolant flush and clean and checked for bubbles in the coolant like you said and nothing? Im not loosing any coolant because last time i changed it was 6 months ago and it's still topped up. Starting to think there is a blockage somewhere? Might do another flush and clean on the weekend.
Cheers
Steve.

Hi Steve, Thanks too for yours.

I have not attached the watchdog temp gauge (which is currently in my garage) to the SC. It might frighten me if I do!! I bought it because of the problems with the Town Ace and chose to remove it before selling the vehicle. I guess if yours has been behaving this way for a year and there are no bubbles and no coolant loss, and you are not towing heavy things up big hills, then maybe ..... but it is not good. I will fit the watchdog to mine in the near future and get back to you on my findings. Hoping .... hoping ... hoping ... mine is not doing the same as yours! I shall talk to you again in the not too far distant future. Richard.

Hi Steve, when I first got mine it was running a bit hot.
Being you take your off the beaten track maybe check if grass is blocking air gap between vertical radiator and auto trans oil cooler.
Can be a tedious job to dig it out with a piece of wire only got about 10mm space there.
I pulled out half of Japan country side from mine and it;s been good ever since .
Even pushing it up Mt Ousley every weekend doesn't affect temp one bit.
Good Luck

Spanner wrote:

Hi Steve, Thanks too for yours.

I have not attached the watchdog temp gauge (which is currently in my garage) to the SC. It might frighten me if I do!! I bought it because of the problems with the Town Ace and chose to remove it before selling the vehicle. I guess if yours has been behaving this way for a year and there are no bubbles and no coolant loss, and you are not towing heavy things up big hills, then maybe ..... but it is not good. I will fit the watchdog to mine in the near future and get back to you on my findings. Hoping .... hoping ... hoping ... mine is not doing the same as yours! I shall talk to you again in the not too far distant future. Richard.

Ok cheers Richard let us know how you go.

mr freeze wrote:

Hi Steve, when I first got mine it was running a bit hot.
Being you take your off the beaten track maybe check if grass is blocking air gap between vertical radiator and auto trans oil cooler.
Can be a tedious job to dig it out with a piece of wire only got about 10mm space there.
I pulled out half of Japan country side from mine and it;s been good ever since .
Even pushing it up Mt Ousley every weekend doesn't affect temp one bit.
Good Luck

Hay Tony, yeah good idea will check it out tomorrow, hope it's my answer! will let ya know.

Hi srburnsy,

For what it's worth, once warmed up, mine has never made it past halfway up the gauge (where the little thermometer icon in the middle is). This included the 47deg day we had last year (yes, I was running the aircon) and 35deg towing a 1.5 ton van. It sits there on cold days too after warming up. I don't have a separate gauge on it to tell you what that temp is though. It never seems too hot and hasn't used any coolant in the more than 2 years I've had it. It seems that they normally have reserve capacity in spades.

Not sure how long water pumps last on these but if one were to have the impeller fail it would cause an overall loss of cooling capacity which might present the above symptoms. The only way to test without removing the pump is to crank it with a hose off. (unless you have some kind of flowmeter in your kit :-). Hopefully it will be something simpler like mr freeze's problem. I will watch this space with interest.

Hi guys,

I have fitted the temperature Watchdog and am encouraged by what it is showing. I fitted the sensor to the lower bolt of the coolant filler neck at the front of the engine so it is exposed to coolant temperature as it is leaving the engine bound for the radiator. The highest temperature I have seen is 90 degrees and that was at the top of a long hill on a hot summer day. I have no doubt that it would get hotter if I was towing a van or some other heavy trailer. Most of the time it is running at between 70 and 80 for city type driving.

There is a possibility that there could be a problem with the impeller on the water pump. I was at a radiator repair place a couple of years ago (in relation to a different vehicle) and the guy was working on a Tarao. He showed me the water pump and I was staggered to see that the impeller had failed. The centre boss part of it was still attached to the shaft but the outer rim of it was no longer attached to the boss!! I have never seen anything like it. The impeller was pressed from sheet material - it was not a casting. It had to have been a metal fatigue issue that caused it to fail.

If your problem is a continuing one and your efforts to solve have come to nothing, maybe you need to be checking out the water pump.

Cheers, Richard

Thanks for the advice guys, it's good to know what the normal temperature should be. I forgot about the water pump, I need to replace the radiator so i will do the water pump as well.

It seem every time ive got a new problem... Found a nice puddle of engine oil on the drive way today, had a good look and found the source of the problem to be a cracked oil pipe going to the turbo I found that the Toyota Surf boy's have had the same problem. Anyone else had this yet? looks to be a bugger of a job. http://dahn.webcity.com.au/~toy49040/forum/viewtopic.php?t=17611