ENGINE WATER TEMP - HOW HOT IS TO HOT?

[MEX]

Hello all,

I have installed an aftermarket temperature guage to my tb42 maverick so I can see what is going on. What I need to know is how hot is to hot?

What should be a normal running temperature on a hot day & when should I be getting worried.

I don't believe I have issues unless I'm towing.

Cheers MEX

[ricduza]

Every vehicle is different. You will need to consult the workshop manual to find out at what temp, the thermostat operates at. For my vehicle, I have an 88 degree thermostat and the thermo fans kick in at about 92 degrees from memory. I have calibrated my temp guage so I know that the mid point on the guage is also 92 degrees and the start of the hot zone is 100 degrees. The end of the hot zone is around 106 degrees. Whilst water boils at 100 degrees, because the radiator water is under pressure, it boils at a higher temp. I have figured that for my vehicle the boiling point is around 110degrees, ie the point where you start losing coolant thru the overflow. You can also increase the boiling point by using a glycol type coolant, but ultimstely that could be dangerous if the coolant temp gets hot enough, it may damage a head gasket or warp the head. Commodore V6s run at quite high temps (I think the thermostat operates at around 102 degrees), but they have a cast iron block. My recent experience with the 1UZ motor, shows it seems to operate fine around 100 degrees, but I'm trying to design the system to keep the temp down to the mid 90s.
If you want to check your temp guage, most better quality multimeters now have a temp guage with them and you can sit your temp sender in a saucepan of water on the stove, stick the thermocouple from the multimeter in there with it and compare the reading with that of your temp guage. This means you will have to dismantle your instrument cluster and also plonk a battery down on the benchtop, but if you wait till the wife is out there should be no problems.

[MEX]

ricduza,

Thanks for the advice. I have another question.

I want to install AU thermo fans which are temperature controlled. Obviously the "switch on" temperature will be set higher than the thermostate opening temperature. Where should the "switch off" temperature be set?

Would it be a couple of degree below the thermostate opening temperature?

Cheers MEX

[fnqcairns]

I have a near stock standard 95 na td42 GQ LWB when I bought the vehicle it had a stuck open thermostat so it would never close the last 2mm or so, also have fitted an aftermarket temp guage.

Any way I replaced this thermo with another genuine one but tested it first and found it to be faulty as it wouldn't open as far as it should so got an exchange, these were the approx 70degC thermos, the same as fitted from new.

I then found my engine with the replacement simply wouldn't get much hotter than 72deg, got worried over this and bought a genuine approx 80deg thermostat (think it is actually an 82deg) now 79-81deg is the limit with aircon on but I have seen 85deg when towing which is about a needle width more than 1/3 on the original dash guage.

I have ever since owning this GQ wondered what IS the optimum temperature to run them at for a long life and a proper burn but every expert has pulled a different number out of their bum it seems, I do think I am still running a little cool but much warmer than the factory fitted thermo-confusing!!!

Not much help to you but with such a range of thermos to suit identical engines and taking into account a engine that is cooling as designed like mine is/does, how in the hell can Nissan justify not having any one single mandated correct running temp for this engine just like every other engine on the face of the earth has, seems extra extra extra fluffy on their part.

cheers fnq

[GQ Bear]

ricduza,

Thanks for the advice. I have another question.

I want to install AU thermo fans which are temperature controlled. Obviously the "switch on" temperature will be set higher than the thermostate opening temperature. Where should the "switch off" temperature be set?

Would it be a couple of degree below the thermostate opening temperature?

Cheers MEX

I'm not sure what temp switch to use, but a good idea with thermos is to have a manual overide so you can switch them on if switch fails and off when crossing waterways, bogholes, etc.

[Zac Zec]

thermostat is fully open at 95 deg. stars to open at 82