Outer Limits 4x4 Board

have a 80 series 1hz with safari turbo and top mount intercooler started getting hot when put under load as in up long hills or towing running 12psi with pyro never reaches 550 , have new geniune radiator, water pump, thermostat and clutch hub has new oil in it and works good, have been told by a mechanic that he has changed head studs on 1hz's with aftermarket turbo to fix overheating problem anyone else heard of this any other suggestions would be appreciated has 450000klm on it turbo been on four 40000klms

when you say hot what do you mean? do you have a proper temp guage?


It's alot of km's too you could have a cracked head. the 1hz heads are prone to it.

will overheat when pushed long enough i just got a portable temp gauge and will double chek the temp dont think it a head because i dont have any signs but will have the water checked this week for gases

Temp will rise if the engine is being laboured. The same used to happen on my Coaster with turboed 1HZ. Never boiled though just rose a lot higher than normal.

I used to get around this by using a lower gear to keep revs around 3,000 on long hills etc. That way your not labouring it (and possibly over fuelling). Even though the pyro only gets to 550, if you maintain that for long enough, engine temp will build up.

I had a similar problem, but a new fan clutch fixed it. The previous one had only been on for under 2 years. Both being non genuine. I haven't changed the oil in the fan clutch, just replaced it and it fixed the problem.
Not saying that this will be your problem as well but,

Do you have anything blocking the radiator light big driving lights? Is your fan shroud attached? Also, do you have a decent size exhaust near the turbo? Perhaps you need to look at the fuel levels (get this checked by someone with a dyno).

Driving in a lower gear at higher revs did temporarily fix the problem for me, but now with the new fan clutch, I can stay in 5th with the pyro on 400 and the water stays at 1mm under the half way line. And thats towing around 2300kg!

Fix it before the problem gets worse and costs you much more.

may have 2 try new clutch hub toyota one is $540 so will be puting after market one in ,always had same driven lights so not that and fuel has been tuned on dyno also have original shroud in place, have to try cleaning the a/c cooler make sure thats not blocked never used to get hot with the turbo set up as is, so something is a miss ,was more wondering if anyone heard of replacing head studs fixing overheating problem on 1hz with turbo

bigdee wrote:may have 2 try new clutch hub toyota one is $540 so will be puting after market one in ,always had same driven lights so not that and fuel has been tuned on dyno also have original shroud in place, have to try cleaning the a/c cooler make sure thats not blocked never used to get hot with the turbo set up as is, so something is a miss ,was more wondering if anyone heard of replacing head studs fixing overheating problem on 1hz with turbo

Check that the ac condensor is nice and clear of bugs etc, but I reckon you shoud remove the lights jsut as a test. Apart from that, yeah the aftermarket fan clutches are fine. They won't last as long as original, but you can get 3 or so at the price of an original. I got my last one from Don Kyatt. Can't comment about the head studs, my 1hz has 380k on it, had 300 or so when I turboed it and knock on wood, the rocker cover last came off for the valve adjustments many services ago.

Just out of curiosity, have you had the injectors checked?

i have this same problem right now. im not loosing coolant so i dont think its a cracked head. i removed radiator and found bottom third full of mud and tryed to wash it out but the fins went with it too but i put it back in and still was better then before so ive ordered a new radiator and ill do the thermostat at the same time as well as thermo fans ill keep u posted as this should be done this weekend!!!!

Had similar problems and chased most of the above culprits...

It ended up being a radiator cap....

http://neuralfibre.com/paul/4wd/tuning- ... fan-clutch

I have money it's the fan clutch.

Factory is better then aftermarket.

Paul

My 80 was overheating porbably 4 or so years ago. Replaced the oil in the fan clutch and it has been working great ever since!

ok so i put twin thermos on mine with no differance now had the head off and done put back on with thicker headgasket to decompress the engine a little and have put a pyro gauge on it going up hills egt's were 320 and temp gauge was starting to get hot (i thought i remembered somewhere on here that upto 550 was acceptable is that right???) so turned around n went back home... might get aftermarket temp gauge installed to see what actual temp its getting too and might go get myself a new cluch fan and hub and re install the original shroud....

me3@neuralfibre.com wrote:http://neuralfibre.com/paul/4wd/tuning- ... fan-clutch

I have money it's the fan clutch.

Factory is better then aftermarket.

Paul

Take the time to read and follow up on paul's advice.
From memory there is a bit there on his blog or page, including a how to to get the fan clutch adjusted and operational.
Fan clutch seems to be common fail.

Toy80Diesel wrote:Driving in a lower gear at higher revs did temporarily fix the problem for me, but now with the new fan clutch, I can stay in 5th with the pyro on 400 and the water stays at 1mm under the half way line. And thats towing around 2300kg!

Have you had to rebuild your gearbox yet? Towing a heavy load like that in 5th will destroy your mainshaft.

i have read where a few people have just fitted two tubes of oil to the fan hub. i think from memory a tube was around 10 to 20 dollars each. alot cheaper than buying a new fan hub.

shlacks wrote:ok so i put twin thermos on mine . . . . .

and might go get myself a new cluch fan and hub and re install the original shroud....

did the thermos have a proper shroud around them??

the standard fan would be a better option than poorly matched or fitted thermos IMO

shlacks wrote:i have this same problem right now. im not loosing coolant so i dont think its a cracked head. i removed radiator and found bottom third full of mud and tryed to wash it out but the fins went with it too but i put it back in and still was better then before so ive ordered a new radiator and ill do the thermostat at the same time as well as thermo fans ill keep u posted as this should be done this weekend!!!!

just because u r not loosing coolant does not mean your head is not cracked
when your head cracks the water does not leak out the crack (as most think) the gas from the combustion leaks into the water
what happens is u end up with gas bubbles in the head and the truck overheats
water normally flows to the overflow bottle then when the engine cools it gets sucked back again so no water usage
this went on for ages for me
i did fan ,fan shroud,rad cap
till finally i put compressed air into each glow plug and checked for bubbles bingo cracked head
other wise truck drove fine and it would only over heat when loaded going up hills

hey yes thermos have full shroud covering whole radiator so its sucked through the whole thing....

and the head isnt cracked as its been off and sent tested and rebuilt... did need combustion chambers seats and guides but had no cracks...

buying an aftermarket coolant temp sensor to see wat temp its actually getting too... to rule out dodgy gauge or sensor and then going back to original (new) shroud, viscous hub and fan...

will compression test cylinders tho to rule it out cracked head myself even tho they said they tested it

shlacks wrote:hey yes thermos have full shroud covering whole radiator so its sucked through the whole thing....

and the head isnt cracked as its been off and sent tested and rebuilt... did need combustion chambers seats and guides but had no cracks...

buying an aftermarket coolant temp sensor to see wat temp its actually getting too... to rule out dodgy gauge or sensor and then going back to original (new) shroud, viscous hub and fan...

will compression test cylinders tho to rule it out cracked head myself even tho they said they tested it

Post on my site (http://www.neuralfibre.com/paul" onclick="window.open(this.href);return false;) about how to mod your factory temp gauge to be accurate across the range.
OEM clutch is better than the aftermarkets I pulled apart - more engagement area.
They need more fluid though - 1.5 tubes, even from new.
There are 4 or 5 different fans. The blue spot one is the most aggressive but renowned for damaging radiators in water crossings. I have an ornage one I think.
Radiators - opinions vary.

I still have money on the clutch.

Paul

well i found the shroud and radiator i took out of it but seems ive misplaced the viscous hub and fan.... is aftermarket any good? why isnt it good? and how much for genuine stuff does anyone know?

put new fan and viscous hub on cruiser today and drove up the hill... got further before getting really hot exhaust temps where getting to 440c

ok put new aftermarket gauge and sender in car to get more of an idea of what temp its actually getting to and turnes out its only getting too just over 90c going up a long hill which in my opinion is fine idle temp is just under 80c so turns out it was probably a gauge or sender problem all along.....