High Temp Going Up Hill

[NEZ]

on the motorway yesterday we had a long hill to climb, sitting at 70 ish and keeping it there up the hill the gearbox kicked down a gear and revs were up to 4000 rpm.
held there till reached top of hill but temp guage was almost to max.
is this normal or do i have a fault??

[fatfires]

on the motorway yesterday we had a long hill to climb, sitting at 70 ish and keeping it there up the hill the gearbox kicked down a gear and revs were up to 4000 rpm.
held there till reached top of hill but temp guage was almost to max.
is this normal or do i have a fault??

normal ....ish, you dont want to do it too often tho....read on here about overheating issues, rads, ATF coolers etc (it can happen to a 3.0L as well!)

[NiftyNev]

You have a problem. The air con will cut out if engine is too hot. Could be viscous fan not working properly or even the thermo fan. Cooling system may be blocked partially in the radiator and need a good flush or radiator recon.

Nev

[NEZ]

You have a problem. The air con will cut out if engine is too hot. Could be viscous fan not working properly or even the thermo fan. Cooling system may be blocked partially in the radiator and need a good flush or radiator recon.

Nev

yes my air con cuts out too, what would you recommend checking and how??
i can manage the flush of cooling system fine for starters but the other bits????

[Tallyman]

Probably first thing is to check that the radiator cooling fins are clear and not clogged with mud, leaves, etc. If so, try giving it a good go with a pressure washer.

If the rad is clear, check first that your coolant is full (under the rad cap) and that the water level in the expansion bottle is no more than about half way up the bottle. Next check that the fan is working OK. If it's the standard viscous fan they tend to lose the oil over the years and will not work properly under load. There is a large thread on here on how to fix it.

Alternative is to fit a thermo electric fan in place of the viscous. That helps cut down the load on the engine and also means you can put in a kill switch if you do any offroading through deeper water.

Next also look at the ATF oil cooler. Pulling up hill at 70 mph will put a lot of heat into the ATF fluid. That heat transfers to the bottom of the coolant radiator just where you really don't want it when the engine is already under load and producing loads of heat on its own. So look at fitting an auxhilliary ATF oil cooler in line with the original to take some of the heat out of the ATF fluid before it gets to the radiator.

Also check rad cap, thermostat and make sure you've no air locks in the system by opening both the front and rear heater taps and, with the engine cold, run the engine with the front slightly high and the rad cap removed to make sure any air is expelled from the system. Also make sure if you need to top up the coolant that you use matching fluid. If it's got Toyota Red in it then don't mix it with any other colour. It's not that expensive to use the the genuine coolant.