Prado thermostat

[Wilddoc Lurker Find all posts View Profile Close Wilddoc]

Goddday all
I am new to the forum and would like some advice from the experts
I did read most of the treats on the overheating of the Prado
I have got a V6 3.4 Petrol 320000 on clock
Getting warm if I go up hil slowly or stands in traffic. Never gets to boiling point
This started 1 year ago
Changed the following
Viscose fan
Thermostat
Oilcooler
Head gasget
Heads was checked all ok
Radiator flushed
Then it was normal till last week took it for a spin on a hot day
As soon as I go up a hill the temp goes up but if I push up the revs the temp came down
So I got toyota rad cap and new thermostat
Checked old and new thermostat all opens up
Put it back. Problem worse. Never got to boiling
Took out the thermostat and no problem
So ? Cause
Airlock? I got the feeling that the water around thermostat is not getting warm enough for the thermostat to open up.
The bottom part of Radiator stays cool if the thermostat is in
It warms up nicely if I take the thermostat ou
After I read how the replace the antifreez I thing the previous machanic did not do it proparlly and I wonder if a block in the system can give me al this.
While I had to wait for the oilcooler they by passed the oilcooler and there was no heating problem
Staying in South Africa do I realy need a thermostat?
Sorry for long story

[scottkz Senior Member Find all posts View Profile Close scottkz]

You do need a thermostat
Replace the water pump

[Wilddoc Lurker Find all posts View Profile Close Wilddoc]

Thanks will do that.

[Playdoh96 Member Find all posts View Profile Close Playdoh96]

Sound's like you've done most thing's, but have you checked that the a/c condenser not blocked in front of the radiator?? Just a thought

[stu#71 Junior Member Find all posts View Profile Close stu#71]

Have you done the obvious...change the radiator. 330k it's probably blocked by now and a flush ain't gonna clear it. You can go for a thicker one which will be more efficient.
The temp gauges in the dash are worse than crap. They have a resistor in them which makes them stay fixed. I've installed an aftermarket one and watch the water temp vary from 70 something to 99 and the dashboard doesn't flinch one bit!

[brissy Member Find all posts View Profile Close brissy]

new radiator and cap , check overflow hose for cracks or just renew this needs to be airtight too

[Wilddoc Lurker Find all posts View Profile Close Wilddoc]

Had it at the Radiator people. They think it is an airlock. Water flowing well if you look into the Radiator. Did the Chemical test and no gas in the water. Thank goodness for that.
I am going to Flush the system again and make sure not to get an airlock. Then put the Thermostat back and see

[glen_ep Addicted PP Member Find all posts View Profile Close glen_ep]

The radiators only last 200,000 / 10 years so if above that, forget cleaning, it's time to change it. Especially important if it's overheated a few times, as they get warped and thus will never again hold enough pressure to maintain lower temperatures.

[stu#71 Junior Member Find all posts View Profile Close stu#71]

If your radiator people aren't suggsting to you to install a new one after 330k you should go somewhere else. Air lock my arse. Or you could risk an overheat and spend $5k on a new engine. Up to you ��

[Wilddoc Lurker Find all posts View Profile Close Wilddoc]

I Drained the system. Put a hose pipe into the heater inlet and ran through some clean water. Then I Drilled another small hole into the side of the Thermostat and put it back.
Filled the radiator with the inlet to the heater open. Once full I started the engine and put more water into the heater inlet. Ran engine for long till all air was out.Took it for a spin and all good. Must admit that it was not very hot. Will take it for a long up hill trip tomorrow.
The Gauge is on it old spot and does not move.
Hope to give good feedback after the weekend.
Leon

[Wilddoc Lurker Find all posts View Profile Close Wilddoc]

I see that the prado is starting to use water. Not from resavor but if I open the radiator cap the water is low. If I fil it up and let it idle there is always a few bubbles coming out. I think the head gasget is gone again. Will do the leak test this week to see if there is gas in the system.
The prado is going in for panelbeating this week after hail damage. Then I will look at cooling system
I think it is time for a replacement.

[Ken in Cairns Junior Member Find all posts View Profile Close Ken in Cairns]

Yep I would do the radiator, especially is the top tank is nor black anymore, they go a chocolate brown colour and then get micro-cracks and leak.
Do the water pump and timing belt at the same time.

As to the clutch fan they can be overhauled for 22 bucks, you need two 11cc tubes of 10,000 Centistoke oil from Mr T
see this links about how to do it, and set the operating temperature up correctly.

http://neuralfibre.com/paul/4wd/tuni...ous-fan-clutch

another link here

http://www.offroad80s.com/how-to-top...mod-t1160.html

Hope that helps

[Wilddoc Lurker Find all posts View Profile Close Wilddoc]

Thanks will do
Leon