Temp gage close to red

[BUSHWHACKER]

I have removed the guards already and was consideing putting a couple of scoops on there , I did not have these problems before changing the block.
gonna check the rad this savvo make sure no airlock in there .....
its like a never ending job having a surf lol

Vents, not scoops! See Lexurf VII photos it has Focus RS vents, nice and subtle.

Savvo?

[MIleshighhopes]

Vents, not scoops! See Lexurf VII photos it has Focus RS vents, nice and subtle.

Savvo?

This very afternoon sir ha ha

Yeah ill look into the vents cheers

[TonyN]

Bogus, the stock ATF cooler is in the bottom of the rad, right by the coolant outlet back into the engine, its well large enough to effect coolant temps.

If you ATF is running really hot, you will heat the engine coolant just as it leaves the rad and goes back into the engine.

So all the work your rad has done cooling the coolant is wasted, it doesn't get a chance to cool off any more as its already heading back into the engine, so engine runs way hotter when the truck is towing, working hard up hills or even just trying to turn 33's at motorway speeds.

Trust me, before removing the AFT cooler I could control engine temps with the accelorator pedal with 35's or towing on the motorway. After removing ATF cooler from rad, engine stays at running temps all the time apart real extremes of load.

A/C will go off at high engine temps, and when autobox is in kick down, and probably a few other times to.

Not going to argue that, but I still cant get my head around the idea, that ATF heat can make a significant difference to engine heat. No matter how hot the ATF gets, I cant see enough heat transfer from that totty wee exchanger in the bottom of the rad taking place to make much difference.

[Bogus]

Trust me, before removing the AFT cooler I could control engine temps with the accelorator pedal with 35's or towing on the motorway. After removing ATF cooler from rad, engine stays at running temps all the time apart real extremes of load.

A/C will go off at high engine temps, and when autobox is in kick down, and probably a few other times to.

Of course I trust you. I just had the idea that the tranny cooler was too small to have sufficient surface area to make a significant difference and also my own set up always shows ATF temps lower than jacket water, even when towing up a long hill.

[TonyN]

Yeah, they should be if everything is running happily.

The AT/Temp light dosn't come on till something like 150C/300deg F and the ODB ECU will record temps of up to 250C/400F before spitting its dummy out, which is almost double normal autobox operating temp, and will boil your coolant quite happily.



A 3rd Gen should quite happily tow 2800kg without hassle, but 2nd Gens are much lower, UK 4Runners say 2200kg, but lots of US specs say as little as 1500kg before you're beating the design specs. Which of course is also pushing 20 years old too, so its no wonder trucks can get hot easily.

[muddle]

bogus, this might help you out, read the bottom paragraph.

http://auto.howstuffworks.com/cooling-system6.htm


just another note, as the cool coolant at the bottom of the rad goes back into the engine the hotter atf will heat it up due to the nature of heat transfer. and because the atf will be hotter under loads such as towing this heat transfer will happen. therefore decreasing the engines cooling capabilities.

[Wolfracer]

"The transmission cooler is like a radiator within a radiator, except instead of exchanging heat with the air, the oil exchanges heat with the coolant in the radiator."

"my own set up always shows ATF temps lower than jacket water, even when towing up a long hill"

If these 2 statements are true, then the ATF MUST absorb energy from the jacket water, effectively cooling the engine!

So, who's fibbing!

Where are you measuring these 2 temps?

[BUSHWHACKER]

"The transmission cooler is like a radiator within a radiator, except instead of exchanging heat with the air, the oil exchanges heat with the coolant in the radiator."

"my own set up always shows ATF temps lower than jacket water, even when towing up a long hill"

If these 2 statements are true, then the ATF MUST absorb energy from the jacket water, effectively cooling the engine!

So, who's fibbing!

Where are you measuring these 2 temps?

I think it's the difference between the 2nd and 3rd gen thats confusing people.

The 3rd gen's radiator is much more efficient and the engine bay is slightly bigger than the 2nd gen's.

[Albannach]

Can you pull away from a standstill quickly or does the gearbox feel like it's slipping?
Could be that the clutch bands aren't tight enough or the torque converter isn't 'locking up'. Either would cause the ATF to get hot quickly.

It pulls away fine and seems to float in and out of 'lock-up' at the right times. It does feel a bit 'slippy' in between though. There is a problem with the kickdown cable, it's too long, so I'm hoping it's that buggering up the pump/pressures. I can't se the reconditioners making a total bollox of the rebuild.

[BUSHWHACKER]

It pulls away fine and seems to float in and out of 'lock-up' at the right times. It does feel a bit 'slippy' in between though. There is a problem with the kickdown cable, it's too long, so I'm hoping it's that buggering up the pump/pressures. I can't se the reconditioners making a total bollox of the rebuild.

I've got a 3.0 auto 'box with the sump removed on the bench if you would like some photos. (In the morning though)

[Bogus]

"The transmission cooler is like a radiator within a radiator, except instead of exchanging heat with the air, the oil exchanges heat with the coolant in the radiator."

"my own set up always shows ATF temps lower than jacket water, even when towing up a long hill"

If these 2 statements are true, then the ATF MUST absorb energy from the jacket water, effectively cooling the engine!

So, who's fibbing!

Where are you measuring these 2 temps?

I have completely bypassed the stock ( in rad) ATF cooler and fitted a stand alone cooler, complete with an 80deg mocal oil stat. Im measuring the temps for the jacket water in the same place as everyone else. Top hose, where it enters the rad. Im measuring the temp of the atf on the line which comes from the transmission and goes to the rad ( or bypasses it ) depending on what the stat is doing. Bowling along solo at a steady 55-60-65, on a cool Scottish day, the ATF temp is usually below 80 which means that the ATF isnt even going through the cooler. Tugging a 1500kg load up a hill I had 83 on the ATF and 103 on the jacket water.

[Bogus]

bogus, this might help you out, read the bottom paragraph.

http://auto.howstuffworks.com/cooling-system6.htm


just another note, as the cool coolant at the bottom of the rad goes back into the engine the hotter atf will heat it up due to the nature of heat transfer. and because the atf will be hotter under loads such as towing this heat transfer will happen. therefore decreasing the engines cooling capabilities.

Wow, fantastic stuff. Learning all the time
I think thats it for me now in this thread, before I garner a Thrifty like reputation, if indeed I havent already.

[Wolfracer]

Don't give up Bogus!
So, what we now need to know is by how many degrees can your rad cool the water?
You say "Tugging a 1500kg load up a hill I had 83 on the ATF and 103 on the jacket water."
So, if the rad cools, lets say 30 degrees, then water exiting the rad would be 103-30=73...
In a normal set up, the 83 ATF fluid would pass the COOLED jacket water (at our example of 73) therefore increasing jacket temps, which you aren't measuring at the exit point of the rad...

As I don't know by how many degrees a rad generally cools, I can't prove this arguement, BUT if the cooling is more than 20 degrees, as in you real life temps record, then the rad COULD absorb heat from the ATF...
I think.

[Albannach]

I've got a 3.0 auto 'box with the sump removed on the bench if you would like some photos. (In the morning though)

It's going back in soon, see if they can fix it. But a couple of pictures of how it's supposed to look wouldn't go amiss. Cheers

[muddle]

because there is a small amount of space between rad and viscous fan can you fit a thicker radiator, and if so would this improve cooling enough to be worthwhile, or remove viscous fan and fit large electric fan so you gain loads of space then fit thicker radiator?

just an idea i thought id throw out there.