Actual Coolant Temperatures 2001 Turbo Diesel

[Hanna1 Lurker Find all posts View Profile Close Hanna1]

Hi Guys

I noticed after reading your threads that 1KZ with Auto Trans and overheating are a common topic, mine does strange things and im hoping if someone can tell me if this is normal.

I have an engine watchdog digital gauge connected to one of the bolts on the top radiator hose onto the block, in theory this should be one of the hottest places for the coolant to be.

When climbing large hills this gauge will reach 90-95 degrees with the air con off and me taking it easy (air con easily adds another 2-3 degrees). This has happened several times including the hills coming into newcastle, toowoomba & mt tamborine. The factory gauge climbs to almost the red.

I have replaced the radiator with a genuine denso and replaced the fan clutch and changed the coolant with no changes. I have even removed the driving lights with no changes.

Are these kind of temperatures normal? Has a capacitor fallen off my factory gauge allowing it to climb too early? Or do I keep looking for a problem?

I havent done the water pump or thermostat as I cant source a 71 degree thermostat, toyota can only sell me a 76 degree which I dont want to fit. The radiator place said they were pretty certain it wasnt the water pump.

I have seen threads on this forum where the gauge is still on half with the temperatures mentioned, has anyone had anything similar happen to theirs? I know there is a possibility of a cracked head etc but the car runs great and uses no oil or coolant.

Thanks

Aiden

[LeighW Avid PP Poster! Find all posts View Profile Close LeighW]

You could try removing the thermostate, if the engine then runs cold you know
it is a thermostate issue, Toyota should be able to supply the correct thermostate?

Cheers
LeighW

[Hanna1 Lurker Find all posts View Profile Close Hanna1]

Hi Leigh

The thermostat is a nightmare to get to down near the turbo (well thats what ive been told) and many accessories need to be removed to get to it including intercooler piping. I am still trying to find a 71 degree (aftermarket) as toyota no longer stock them and will only supply a 76 degree (which i have bought but dont want to fit).

Thanks,

[tassie tiger Advanced Member Find all posts View Profile Close tassie tiger]

I would replace the thermostat (76 is fine) and then road test.

If the prob remains its probably a cracked head

[Bounder Junior Member Find all posts View Profile Close Bounder]

The stat isn't that bad to get at, just behind the alternator.
This issue has been discussed on this thread in depth where the overheating issue is a problem as well.

[Hanna1 Lurker Find all posts View Profile Close Hanna1]

Thanks Guys, that link to the thermostat thread looks exactly like what I needed.

Will do the thermostat this weekend.

Thanks,

[Hanna1 Lurker Find all posts View Profile Close Hanna1]

Although I will change the thermostat this weekend I an hoping if someone can confirm weather my temperatures are within normal operating range of this engine? or is something not working properly?

THanks,

Aiden

[Bounder Junior Member Find all posts View Profile Close Bounder]

Sounds hot to me. My gauge never moved at all unless there was a problem with the rad.
I think a lot has to do with the Auto trans cooler being in the same unit as the engine coolant rad.
If you could fit an tranny cooler separate to the rad it would probably make a big difference.

[minh Member Find all posts View Profile Close minh]

The toyota you go too are full of shit. 71 degrees thermostats are everywhere.
Here is the part number 90916 - 03121 *Wax 71-90

[minh Member Find all posts View Profile Close minh]

Climbing hills those temperatures are about right. I have an aftermarket temp gauge and it stays around 82 degrees crusing and yes 95 degrees climbing long hills.
I strongly suggest hooking up an aftermarket temp gauge. dont trust a sensor plugged into a bolt.
Secondly DO NOT trust the factory temp gauge. They dont move until its too late.
It does not move from its normal position until 105 degrees.
SO anyone who thinks their car doesnt overheat because they rely on the factory gauge. DONT!

[Hanna1 Lurker Find all posts View Profile Close Hanna1]

Thanks Guys

Minh, if you are getting 95 climbing hills and 82 cruising that is the same temperatures I am getting, my problem is that by 93 on my digital gauge my factory gauge is in the red so I cant tell what is at fault.

I will get a coolant sensor that has a probe direct into the coolant and see if the temperatures are the same, if they are I will assume that my factory gauge is malfunctioning and rising too early.

I will also change the thermostat with the part number you mentioned.

Thanks,

[croozza Avid PP Poster! Find all posts View Profile Close croozza]

Thanks Guys

Minh, if you are getting 95 climbing hills and 82 cruising that is the same temperatures I am getting, my problem is that by 93 on my digital gauge my factory gauge is in the red so I cant tell what is at fault.

I will get a coolant sensor that has a probe direct into the coolant and see if the temperatures are the same, if they are I will assume that my factory gauge is malfunctioning and rising too early.

I will also change the thermostat with the part number you mentioned.

Thanks,

Just remember the factory gauge is a guide only, it only measures an approx temp.

[minh Member Find all posts View Profile Close minh]

The temp sender for your factory gauge costs like 20 bucks. Replace that aswell. Easy to get too.
When you look from the passenger side in the engine bay. Just above your injection pump. YOu can see a skinny cable plugged into a sensor into the head. Do a test by disconnecting it and watch the factory guage not work. Then you know you located the right one.

Change that. Thats the sender for your factory guage. Cheap enough so just change it. Go to any autospares. Trident brand.

Could be that your factory sender for the gauge is faulty or previous owner has done a mod so it reads more accuratelty rather than just sit in the middle until you overheat.

[minh Member Find all posts View Profile Close minh]

http://www.ebay.com.au/itm/12v-Digit...item19c3999df9
You will need this too.
Our hoses are 37mm but go 38mm for a better fit.
http://www.ebay.com.au/itm/38mm-wate...item43a6a644a4


Then your set. Real coolant reading from a more accurate guage.

If in doubt just do the right thing by your car.
New:
Radiator
Water pump
Thermostate
Fan clutch
Coolant flush.

Atleast summer you know you are good to go.

[Hawk Thor Junior Member Find all posts View Profile Close Hawk Thor]

I personally think that an EGT gauge is a better gauge to stare at while climbing hills or towing loads. My EGT figures scare me more that coolant temp ever will.