Outer Limits 4x4 Board

i have a 96 2.8 lux with a ct20 turbo setuo from a surf on it. it runs perfect around town, never gets hot. problem is any speed greater the about 90kmh it gets hot, i have tried everything to fix the problem. i have installed a new 4 core radiator from aussi coolers, has been tuned to run 8psi and the egt is set to run no more the a safe 520. i do run 35's but also run 4.8 diff gears to take some load off things. 10inch thermo on the front of the aircon cooler thingi, I need help im outa idea's. could it be an internal engine problem? is it the size of the turbo? any help would be great!

is the thermostat opening?
water circulating through the radiator (water pump)
the fan will also be doing nothing. to much gap between fan, a/c condenser, and radiator.

try mounting the fan on the inside of the radiator.
also are you running a engine driven fan?

yep its a brand new thermostat, i still run the standard engine fan, and there is only 1to2 cm gap between the fan and the radiator because its a 4core and thicker then standard, so no room for a thermo on the inside. i have not replaced the water pump for the simple fact that it doesnt get hot around town or while 4x4in, can idle it ages and it stays at the normal temp

Bit of a long shot but have you replaced the temp sender? These have been known to play up.

its sounds stupid but check the oil if its really low it will overheat i was so worried about everythin else being wrong i forgot about the oil level.

have you checked to see if you have a blown head gasket?

edit - normally overheating at high speeds is either a flow problem or an internal problem. have you cooling system co tested for leaking combustion chamber gases.

yep i have installed a automteter temp gauge and new sender to suit it, oil level is ok to. thanks for ideas though. it doesnt have bubbles that i can see in the top tank with the cap off while running, but i think thats a good start, i will get the head gasket checked monday. thanks. any other info would be great.

also check water pump. these motors are a little prone to chewing out the back of the water pump (block side).

Take off the front protection pan NOW!

I was like you and could not find a problem with the cooling system or tune/fuel ect. Overheated when towing me light camper, and also when not towing in soft sand. Took off the protection plate and no more problems.

what is the protection plate lol ?????

It's a big metal pan that covers the underside from the radiator to the sump and is the width of the veichle.
If your rig is modded a lot it may be missin already. If you aint got winch and lights, it may be a problem and you may need to fit one to shroud the engine bay more.

I got winch and lights up front restricting air flow to the rad, so removing the plate fixed the prob as I susspect it caused an area of low pressure at that point which improved air flow.

Just goes to show different set ups need different set ups.

If your rig is moded lots you may have to get a custom made one to fit.

start the car and wait for about 10 seconds then feel the top radiator hose for pressure. if its really hard then its a cracked head if its soft then its good news and its not.

I checked this moring and it doesnt have the origanal sump plate on it at all. and also started it to waited 10 seconds and the top radiator hose did not build up pressure and get hard So this means the head is all good? or should i still get it checked to be positive

2.8's are prone to cracking so it may pay to check. When I cracked mine I was loseing water, but you may even get bubbles in the water when you remove the rad cap and look with it running.
New head, water pump, radiator, fan, fan clutch, thermostat, and mine still got hot. removed the pan and all good.
Do you have lights ect fitted that restrict airflow to rad ?

I had the exact same problem with mine and replaced everything to do with the cooling and nothing worked.
I had it dyno tuned and it turned out the fuel timing was out. Solved the problem for me.

Ok so im gunna try and get the head checked monday, i do have a set of 240 blitz spotties on it but have removed them and it still got hot. I have had it dyno tuned so the fuel its getting should be correct. as for the fuel timing?? what does this mean?

also the engine has only done 175 000k the turbo was fitted at 150 000. i was thinking, maybe because the turbo is to suit a 2.4d and its a little to small it overheats the engine as it runs full boost at 100kmph. thats alot of heat for the engine to handle. does that make sense???

what boost is it set to ?

is the turbo water cooled?

a little odd that its sitting on full boost at 100km/h cruise (is speedo correct especialy with bigger tires and different diffs).
while the turbo is on the small size there is plenty of those conversions that don't heat up.

could well be someones up the fuel to much.

also check the rad, someone mentioned a few problems with some of the imported coolers a few shops are fitting.
did you actually check the thermostat? quite a few of the after market ones have been found to open too little or too slowly.

I've got a DTS turbo kit on my 2.8 Standard radiator, water cooled turbo, only had the injector pump recalibrated for the turbo when I fitted it. This was more then 100,000k's ago and still no problems, up and down the highway, camper trailer or not, never gets hot.
If you have done everything else I might be checking the fuel/tuning as others have suggested. My injector pump was completely rebuilt for the turbo, cost a fricken fortune for it, but as said, never had a problem with it.

its set at 8psi, yes the speedo is out but have checked it with a gps and i know where 100kmph is. turbo is water cooled. my rad is a 4 core upgaded from the standard 3 core. made by aussi desert coolers. i have fitted a new thermostat but its aftermarket. i will get a genuine one from toyota tomorrow. I think i will get the fuel tuning checked as well and see how i go then.

I run 11psi on Safari turbo no probs. As for full boost at 100kmh it should help not hinder. Turbo on a deisel just crams more air in, more air = engine runs leaner and EGT drop. Less air and engine runs rich and egt rise.
You can turn up the fuel when you add a turbo as you introduce more air and the engine can then handle more fuel.
Petrol engines are the other way round, lean=hot, rich=cool.

I found when mine got hot I droped down a gear for more revs and max boost and I could get the engine leaner and cooler. More boost is good so if ya got the surf turbo, space out the waste gate vacume modulater with 1mm thick washers at first and get it up to 10 psi without touching the fuel and this may just fix it.

One more thing. When I used to have an early holden they run a spring inside the bottom rad hose to stop it colapsing at speed and restricting coolant flow. Check if the lux runs this spring in the bottom hose from factory. If so squeez the bottom hose of yours and see if you can compress it with the engine stopped of course.

stock hilux fans ar prone to snap off blades too.

muddylux wrote: As for full boost at 100kmh it should help not hinder.

yes/no.

boost is a reaction to the fuel being burnt. at cruise there should be little amount of fuel burnt hence small amount of boost. it could be normal as its a small turbo. i'm not sure what they normally have at cruise. it could also be a sign of something being wrong eg retarded timing (slipped cam belt), restriction somewhere or poor compession. basicly pouring in the fuel but not making the power.

I'm pretty sure they only use springs in radiator hoses to prevent it from squashing when the vechile is cooling down and trying to such fluid from the overflow back into the cooling system. Possitive pressure due to heat prevents this happening while the vechile is running

Ok guys i may have found the answer. I think the nswer is in the water pumps, if you have an issue which does not go along with this please notify me asap.
I think the aftermarket pumps are the issue, the people that have issues are the ones with aftermarket pumps, and the all good ones are genuine pumps. I'll do some more work on this and get back to you. oh yeah and posily the thermostat aswell.

Definitely Your injection pump, hook up a piro meter and tune the pump so its getting the right amount of fuel, do the timing, and do your injectors, she'll be sweet

Someone suggested to reco the fan hub. my wshop manual says its a throw away item and can not be reco'd. anyone done this

hey mate i had the same turbo setup on my lux but i was running 14psi boost and shit load of fuel and it never got hot even towing a trailer the pyro would creep up around the five hundred mark on hills but labouring the motor would make the pyro creep up a bit more but never the temp gauge, have u got any gauges in the truck like pyro or boost gauges

Hey Yeah Burdy i have a boost gauge it runs 9psi. i had it tuned and it was ment to be tuned so the egt did not go above 520, maybe its time to get a pyro gauge.