Overheating Need Help!

[Mitchpato]

Hi all I have a 99 toyota hilux 2.7 petrol im running out of answers! It overheats at highway speeds running a/c happins quicker. Ive replaced a number of things it has a new head, radiator, fan clutch, radiator cap, thermostat, flushed system and replaced with new coolent. Pressuse sensor works but is overheating physicaly. What next! Down fall, Is a 4x4 and has a bullbar, winch, big spotlights infront of radiator, in saying this a friend has a 97 hilux which runs same running gear as mine and has similer mods to mine and hasnt got a issue..

[Mitchpato]

Have a high flow exust and extractors which should help again..

[A Grasser]

Hi all I have a 99 toyota hilux 2.7 petrol im running out of answers! It overheats at highway speeds running a/c happins quicker. Ive replaced a number of things it has a new head, radiator, fan clutch, radiator cap, thermostat, flushed system and replaced with new coolent. Pressuse sensor works but is overheating physicaly. What next! Down fall, Is a 4x4 and has a bullbar, winch, big spotlights infront of radiator, in saying this a friend has a 97 hilux which runs same running gear as mine and has similer mods to mine and hasnt got a issue..

Hi,Mitchpato,

Have you tried tightening the fan belts? (stating the obvious)

Water pump is next, the impeller can come off sometimes, also the

crank damper/pulley can break up and slip, induction leaks can cause

lean running, leading to overheating,

Gman.

[Mitchpato]

Thanks for the reply its defently not belt slipping there new also and nice a tight my next step is to pull water pump out and have a look ive currently puttin thermoatats on in and out of radiator to she the temp difference also one on the engine loop to see while driving spoken to mechanics and they are also clueless to what it may be but with the temps ill be idilizeing were abouts the problem is I hope its just weird that its only happing while doing 100km... Up for more suggestions many as I can anything is possible atm...

[igormus]

Thanks for the reply its defently not belt slipping there new also and nice a tight my next step is to pull water pump out and have a look ive currently puttin thermoatats on in and out of radiator to she the temp difference also one on the engine loop to see while driving spoken to mechanics and they are also clueless to what it may be but with the temps ill be idilizeing were abouts the problem is I hope its just weird that its only happing while doing 100km... Up for more suggestions many as I can anything is possible atm...

check with an expansion tank filling lid gasket. it looks like to the pressure inside the cooling system is being released under way.

the less pressure the less boiling temperature. it is like a kitchen kettle now.

check and revert/Cheers/Igor

[Mitchpato]

replace water filling cap aswell even tho its not under pressure I pulled apart my new radiator and found 80% was blocked! pulled out tho stat and acid clean circuit was fairly dirty alot of muddy and sandy flakes came out did it a few times I actuly think the hole block is full of gunk going to take a few gos at cleaning system out over time hopefully thats the problem! Thanks everyone for the help. Whats a good way to flush system out? im using a realy mild blend of hydrocloric acid and water working well but I no it wont be good for it any betterway?

[igormus]

replace water filling cap aswell even tho its not under pressure I pulled apart my new radiator and found 80% was blocked! pulled out tho stat and acid clean circuit was fairly dirty alot of muddy and sandy flakes came out did it a few times I actuly think the hole block is full of gunk going to take a few gos at cleaning system out over time hopefully thats the problem! Thanks everyone for the help. Whats a good way to flush system out? im using a realy mild blend of hydrocloric acid and water working well but I no it wont be good for it any betterway?

the best way to treat in dismatled condition both radiator and cyl block and thoroughly flash them both by water jet.

follow flashing schedule to prevent huge amount of flakes. cheers/Igor

[Vince W]

Is the engine fan working correctly. i.e. is it locking up when the engine is hot?

[jirehn]

I have also a problem with overheating with My Hi Ace Toyota and I don't know why this happening.