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in the morning click it to on but dont start it and log the engine and see if the clt and mat sensors are reading the same thing. They should be pretty close as the air and coolant should both be ambient temp. Thats assuming you have 12p and comms mod. And if not, why not?! haha

antus wrote:in the morning click it to on but dont start it and log the engine and see if the clt and mat sensors are reading the same thing. They should be pretty close as the air and coolant should both be ambient temp. Thats assuming you have 12p and comms mod. And if not, why not?! haha

I just put in the NVRAM ECU in and everything worked as expected, fan come on exactly where I should of on the temp. Plunged the old ECU back and magically the problem is gone! thats the worst! wft? For a sec I thought it was the ECU but now its all good?

could be temp sensor (aftermarket tridon) or connection problem? an intermittent one. I am going ahead and swapping the ECU, temp sensor and clean and check the temp sensor plug and wires.

I agree about genuine Toyota coolant and all the genuine coolants made for Japanese cars. I only use Japanese coolant in all my customers cars as I have no faith in Australian made coolant. I used one brand once only to find out was acidic. The company refused to return phone calls to discuss the issue. I hope their gone belly up with this standard of product.
Have to laugh about my own problem with overheating. I have a great VR BT1 V8 and can you believe me a mechanic drove till it stopped and needed to be pushed out of a roundabout because the car would no longer crank over. I let it cool down started it up and it still goes as good as it ever did. Even better since I tweaked it a bit. I can only think how the piston skirts and bore look but as long as it runs as good as it does I don't intend pulling the engine apart.

Ok, I can not find the cause of the problem but all is good now, they only thing I have in my mind is when I did an oil change few weeks ago, while the engine was running I bumped my hand into the loom where is runs past the shock tower and towards the firewall and the engine almost had a heart attack, I tried everything then to try replicating that event but no dice. I recall rats had a go at the loom in that spot years ago but I can't remember what I did to repair it, might rip the tape off have a look on Saturday.

As a precaution I changed the ECU and temp sensors just for the hell of it.

^ As for your coolant comment, would holden genuine coolant be good?

VL400 wrote:Mazda dealers are also guilty of this, marked a few parts (filter, plugs etc) which were due to be replaced. Picked car up, invoice says they were replaced but oddly the new parts still hard the same markings Got some freebies out of that one and never went back.

In terms of coolant I like the Toyota Long Life stuff. The insides of my 1UZ are sparkling still with no sigh of corrosion on anything, stainless steel thermostat is still a mirror. The 5VZ which is alloy head/iron block has no sign of a rust colour on any of the alloy parts.

its the same as the tectalloy highload red but also has Diethylene Glycol which is why it stays cleaner, http://en.wikipedia.org/wiki/Diethylene_glycol

vlad01 wrote:Ok, I can not find the cause of the problem but all is good now, they only thing I have in my mind is when I did an oil change few weeks ago, while the engine was running I bumped my hand into the loom where is runs past the shock tower and towards the firewall and the engine almost had a heart attack, I tried everything then to try replicating that event but no dice. I recall rats had a go at the loom in that spot years ago but I can't remember what I did to repair it, might rip the tape off have a look on Saturday.

As a precaution I changed the ECU and temp sensors just for the hell of it.

^ As for your coolant comment, would holden genuine coolant be good?

If we can find a datasheet or material safety sheet then we can see what's in it.