Outer Limits 4x4 Board

a well structured question might help your cause.
and some details on your issue...
i turbod my 97 GQ ute.
before i did i replaced the silicon fluid in the viscous fan
got the radiator flushed professionally
and replaced the coolant.

its never overheated.
now running 13 pound boost, unintercooled and fuel pump wound up + gas so it will hit 600* without too much effort.
yes it climbs if you work it, and i have to drive it to the EGTs to keep it under 600 but it doesnt go to the hot mark on the water temps.

jem jem wrote:

yes. and with the awesome amount of info you have given, let the games begin.

I asked a simple question..but here is some info... .. td42 with aftermarket turbo,all the gear, 12psi fueled to suit, 3"pipe ,new clutch fan , new alloy radiator.6"lift 35's, 4:6gears,bar ,winch, rear bar ,draws and tank dosnt overheat but gets extremely close... i have heard of a guy who modify s the water pump fan and makes it bigger. used to do a few comp trucks ...no sure of his name , one thing also its an Auto.. gets alittle hotter than my mates... his is man with same gear. ETG is bout 500-600


Any info would be great. And Ive done the following:new water pump
new clutch fan,thermostat, new alloy radiator , flushed the block, new hoses,belts.. pretty much anything related with cooling

you did the new clutch fan but did you do the fan hub.? i have done all you have as well as fitted a gu td42 fan blade as they are slightly bigger. if you havent done the fan hub I would look there. i put 2 tubes of the silicon from toyota about $10 a tube and they carry it in stock. mine is still not right though. the radiator shop told me to drill a really small hole in outer section of thermostat to help bleed air out. fit an aftermarket temp guage and maybe a seperate cooler for the auto.

i have a td42 with aftermarket turbo kit running 12psi pump turned up a bit, lift and 35,s long range tank front and rear bars, winch and at 120km up a steepish hill the hottest i can get the egt,s after turbo is 550 max and it warms up to a bit over half on temp guage on a hot day so yours is running a bit hot i think maybe check that your radiator does not have a build up of shit on the outside of the core that happened to mine after a muddy weekend run and was warming up.
pulled it out and cleaned it and it was all good again

have you pulled out the radiator and had a look to see if you can see through the fins? i did and spent half hour on the gerni now fixed mine and did the same for a mate yeserday. fixed his aswell.

do the auto patrols have a separate auto cooler or is it a part of the rad like commodores?

run 2x PWR auto coolers with it and bypass the radiator.

and there have been cases of new alloy radiators working worse than the ones they replaced, when did you replace the rad?

love ke70 wrote:and there have been cases of new alloy radiators working worse than the ones they replaced, when did you replace the rad?

true. my brand new alloy 3core , triple flow aussie desert cooler made virtually no difference at all.

Two things i can see not helping:

- As already pointed out, check how your ATF is cooled. If it is integrated, separate it and use a decent heat transfer.

- Being auto, it will be more constantly on boost, so when it's getting pushed it will get hotter quicker (as in heat-soak).

I replaced the radiator (brass), thermostat, coolant and belt on mine and the temp guage doesn't move one bit regardless. The rest of the stuff is 220,000km old (fan, viscous coupling, water pump). From memory i get the pyro up to 550-580 when pushing it hard. I'm only running 7psi though.

running twin oil coolers for the auto... pwr... large... yes changed the coupling for clutch fan... was getting warmer with old brass 4core... got new PWR alloy. made a difference runs everyday under half , hot days gets just under hot.... want to try keep it half way will try larger clutch fan....

What brand bullbar are you running, had some problems on my trip round oz. Was towing a big van though. I have the base model ARB front bar, it has no air slots in the front. If you have this bar or similar try cutting some rectangular slots either side of the winch outlet to help with airflow. I found it improved the efficiency of the cooling, but it would still get hot if pushed hard. Also get the genuine GU thermostat, the GQ one is lower flow. There is a Tridon high flow unit available as well which is near identical to the genuine GU one. If this does not help try drilling (6) 6mm holes in the thermostat to improve flow. Did the Toyota silicon oil in the fan clutch. Also mine has a DTS turbo kit fitted, what is yours and where does the cooling return run back into the system as most kits run the return back into the heater return. This is right next to the temp sender on the engine side of the thermostat, so the extra heat of the turbo can affect the temp sender, the holes that were drilled in the thermostat I placed directly over where the heater return enters the thermo housing. Another idea would be to run this return into the thermostat housing itself, there is a place on the housing to drill and tap. This would place it on the downstream side of the thermostat away from the sender. I saw improvement, measured with a VDO temp gauge before and after the radiator by doing all these mods and it has not gone above half on the factory gauge since.

Try backing the fuel off half a turn. If it has black smoke pissing out of it at full boost and load it is over fueling and you will actually loose power due to heat soak etc. Or get it dyno tuned.

AS well as fuel turned up TOO much (very worth checking), does the truck have a body lift? If so, the necessitated removal of the bottom half of the radiator shroud can change the air flow. I made up an air deflector that made up for this.

Of all the threads that I have read on GQ cooling, this is the most comprehensive!!

If you STILL have cooling issues (particularly with an aftermarket radiator, which most people DON'T find it necessary to go to), you may need to take it to a specialist, preferably one who is familiar with GQ TD42's.

I also use a PWR rad, mine is natural TD42 but have replaced the clutch, hoses, 77* tridon high flow thermostat, and flushed the sh1t out of it but still gets over half on a hot day, let alone with air con on. If it's hot enough to need air con, it's too hot to use the ShortyIQ thing if I have either roof rack or camper in tow (let alone both). What IS the acceptable reading on factory guage? Around town mine sits on a quarter, but hot day in country gets over half and with air con heads toward the door mirror if I leave it on. WTF? Have run out of ideas, sick of guzzling gatorade with windows open on hols in summer!

Buy an aftermarket temp gauge

Nissan gauges are extremely inaccurate and have a massive dead spot in them even when they are working right. At least then you will have a real basis to see your results

I spent so much time chasing overheating issues in my old wagon turned out it was the factory gauge, tho i did replace some sketchy parts too in the hunt for the problem

Just a thought if Nissan gauges are not the best - We fitted a temperature monitor "engine watchdog TM2" (Item #140370330628 on Ebay) to my young blokes 40 series. Yep, 40's gauges are woeful
It measures the actual block temperature, not water temp. This has other advantages if its overheating due to oil or water loss problems. The sensor just goes under a bolt on the head / block of your choice so its easy to fit.
It has an alarm which is set by the user and gives a digital readout of the temp. I was a bit dubious at first but there wasnt much choice for the old 40.

No, I dont flog these units, I just found it to be a pretty useful item and have ordered one for my Pootrol after reading this thread about dodgey gauges

Leeroy wrote:I also use a PWR rad, mine is natural TD42 but have replaced the clutch, hoses, 77* tridon high flow thermostat, and flushed the sh1t out of it but still gets over half on a hot day, let alone with air con on. If it's hot enough to need air con, it's too hot to use the ShortyIQ thing if I have either roof rack or camper in tow (let alone both). What IS the acceptable reading on factory guage? Around town mine sits on a quarter, but hot day in country gets over half and with air con heads toward the door mirror if I leave it on. WTF? Have run out of ideas, sick of guzzling gatorade with windows open on hols in summer!

Now I'm NOT wanting to start a sh*t fight, but MAYBE it COULD be your driving style? I'm not having a go, I'm quite serious!

Diesels are very different to petrols; you over-fuel a petrol, and it cools it down; over fuel a diesel, and it WILL overheat. Simple as too much throttle going up a hill, and this WILL occur. Flooring it in these conditions just over-fuels it, and overheats it. It's NOT a petrol. Also, playing with the injector pump yourself to increase fuel exacerbates this problem.

The whole time I had the Mav', I don't think I revved it over 3000rpm!! Why? Cos' it doesn't need to! A n/a TD42 gets max at about 2000rpm.

Also, a n/a TD42 should be able to stay cool (half or below) in all but the most extreme conditions, unless there is something that you have missed.

Not out to piss anyone off, but there are ALOT of modded TD42 (turbo's + more) owners on this board and the VAST MAJORITY don't have cooling issues, and most have the standard radiators. Me included, have had issues and followed the basic principles as offered earlier in the thread.

also depends on the year model of the TD42 though, the 93 on, and apparently especially the 95 on engines are much more prone to the issue as they thinned the blocks out so much...

Not out to piss anyone off, but there are ALOT of modded TD42 (turbo's + more) owners on this board and the VAST MAJORITY don't have cooling issues, and most have the standard radiators. Me included, have had issues and followed the basic principles as offered earlier in the thread.[/quote]

Thats a big call standard 2 core radiator doesnt like big boost and fuel.
Also every car is different and climate is a big factor aswell.

bigbluemav wrote:Diesels are very different to petrols; you over-fuel a petrol, and it cools it down; over fuel a diesel, and it WILL overheat. Simple as too much throttle going up a hill, and this WILL occur. Flooring it in these conditions just over-fuels it, and overheats it. It's NOT a petrol. Also, playing with the injector pump yourself to increase fuel exacerbates this problem.

I agree 110% on this one. Petrols and diesels are two completely differnt beasts, and there is definately a difference needed in driving style. The way i drive is to find the acceleration fringe and then back off a fraction. Revving diesels never really seems to help too much either.

bigbluemav wrote:The whole time I had the Mav', I don't think I revved it over 3000rpm!! Why? Cos' it doesn't need to! A n/a TD42 gets max at about 2000rpm.

Same here for me too - i don't rev my car over 3000 RPM in either N/A or turbo form. My dyno sheets show peak torque at 1370 RPM, and peak power at 2550 RPM when my GQ was N/A.

bigbluemav wrote:

Leeroy wrote:I also use a PWR rad, mine is natural TD42 but have replaced the clutch, hoses, 77* tridon high flow thermostat, and flushed the sh1t out of it but still gets over half on a hot day, let alone with air con on. If it's hot enough to need air con, it's too hot to use the ShortyIQ thing if I have either roof rack or camper in tow (let alone both). What IS the acceptable reading on factory guage? Around town mine sits on a quarter, but hot day in country gets over half and with air con heads toward the door mirror if I leave it on. WTF? Have run out of ideas, sick of guzzling gatorade with windows open on hols in summer!

Now I'm NOT wanting to start a sh*t fight, but MAYBE it COULD be your driving style? I'm not having a go, I'm quite serious!

Diesels are very different to petrols; you over-fuel a petrol, and it cools it down; over fuel a diesel, and it WILL overheat. Simple as too much throttle going up a hill, and this WILL occur. Flooring it in these conditions just over-fuels it, and overheats it. It's NOT a petrol. Also, playing with the injector pump yourself to increase fuel exacerbates this problem.

The whole time I had the Mav', I don't think I revved it over 3000rpm!! Why? Cos' it doesn't need to! A n/a TD42 gets max at about 2000rpm.

Also, a n/a TD42 should be able to stay cool (half or below) in all but the most extreme conditions, unless there is something that you have missed.

Not out to piss anyone off, but there are ALOT of modded TD42 (turbo's + more) owners on this board and the VAST MAJORITY don't have cooling issues, and most have the standard radiators. Me included, have had issues and followed the basic principles as offered earlier in the thread.

Yeah ok I can understand your thoughts, but I'm talking about sitting on a constant 95 to 105 kph in 4th or 5th, with just enough throttle to hold the speed constant. I have never touched the fuel pump (has been tuned on a dyno by reputable mob over here), and have replaced or checked everything sensible IMHO. The air con seems to be the straw that broke the camel's back, but I wonder how much difference is made by things like lift, tyre size, spots/winch in air flow etc. However most people with juiced up turboes also have most of the above to the same level. I was just interested to see if there was anything I had missed, I will def put in a VDO guage just to see what it ACTUALLY is temp wise, may be worried about nothing, but for the record what IS acceptable temp for a TD42 (1992 silvertop) to sit on in very hot conditions??? Low 90s???

I did everything you can think of to my GU and the last was to fit an oil cooler, after towing my 2ton van to Bundy and back it did not overheat as much and didn't turn off the aircond once, (wife happy) and towed up big hills in third gear doing 80 klm/p something I have not been able to do for a while.

Still don't think the tune up is right as it used more fuel, but that could be because I was able to drive it harder so I backed off and the temp came back down on the hill and still not able to sit in 5th on hills.

Without the van it's doesn't move the gauge in soft sand or driving anywhere else.

Leeroy wrote:

bigbluemav wrote:

Leeroy wrote:I also use a PWR rad, mine is natural TD42 but have replaced the clutch, hoses, 77* tridon high flow thermostat, and flushed the sh1t out of it but still gets over half on a hot day, let alone with air con on. If it's hot enough to need air con, it's too hot to use the ShortyIQ thing if I have either roof rack or camper in tow (let alone both). What IS the acceptable reading on factory guage? Around town mine sits on a quarter, but hot day in country gets over half and with air con heads toward the door mirror if I leave it on. WTF? Have run out of ideas, sick of guzzling gatorade with windows open on hols in summer!

Now I'm NOT wanting to start a sh*t fight, but MAYBE it COULD be your driving style? I'm not having a go, I'm quite serious!

Diesels are very different to petrols; you over-fuel a petrol, and it cools it down; over fuel a diesel, and it WILL overheat. Simple as too much throttle going up a hill, and this WILL occur. Flooring it in these conditions just over-fuels it, and overheats it. It's NOT a petrol. Also, playing with the injector pump yourself to increase fuel exacerbates this problem.

The whole time I had the Mav', I don't think I revved it over 3000rpm!! Why? Cos' it doesn't need to! A n/a TD42 gets max at about 2000rpm.

Also, a n/a TD42 should be able to stay cool (half or below) in all but the most extreme conditions, unless there is something that you have missed.

Not out to piss anyone off, but there are ALOT of modded TD42 (turbo's + more) owners on this board and the VAST MAJORITY don't have cooling issues, and most have the standard radiators. Me included, have had issues and followed the basic principles as offered earlier in the thread.

Yeah ok I can understand your thoughts, but I'm talking about sitting on a constant 95 to 105 kph in 4th or 5th, with just enough throttle to hold the speed constant. I have never touched the fuel pump (has been tuned on a dyno by reputable mob over here), and have replaced or checked everything sensible IMHO. The air con seems to be the straw that broke the camel's back, but I wonder how much difference is made by things like lift, tyre size, spots/winch in air flow etc. However most people with juiced up turboes also have most of the above to the same level. I was just interested to see if there was anything I had missed, I will def put in a VDO guage just to see what it ACTUALLY is temp wise, may be worried about nothing, but for the record what IS acceptable temp for a TD42 (1992 silvertop) to sit on in very hot conditions??? Low 90s???

For the coolant temp it's 118 - 120C Where the needle actually is on the factory gauge at that temp I dont know.

Troll00 wrote:I did everything you can think of to my GU and the last was to fit an oil cooler, after towing my 2ton van to Bundy and back it did not overheat as much and didn't turn off the aircond once, (wife happy) and towed up big hills in third gear doing 80 klm/p something I have not been able to do for a while.

Still don't think the tune up is right as it used more fuel, but that could be because I was able to drive it harder so I backed off and the temp came back down on the hill and still not able to sit in 5th on hills.

Without the van it's doesn't move the gauge in soft sand or driving anywhere else.

Any chance of posting up some pics and details of the oil cooler for future reference?

Big_GQ wrote:Not out to piss anyone off, but there are ALOT of modded TD42 (turbo's + more) owners on this board and the VAST MAJORITY don't have cooling issues, and most have the standard radiators. Me included, have had issues and followed the basic principles as offered earlier in the thread.

Thats a big call standard 2 core radiator doesnt like big boost and fuel.
Also every car is different and climate is a big factor aswell.[/quote]

Actually, the one thing that I did do outside 'standard' was a triple core radiator. But SURELY you'd do THAT before buying an aftermarket item.

Mine was a 1992, and after the triple core was in, I never had a problem, but I did flush the radiator AND the block every year and put in new pre mixed coolant + 500ml of the concentrate.

coxy321 wrote:

bigbluemav wrote:Diesels are very different to petrols; you over-fuel a petrol, and it cools it down; over fuel a diesel, and it WILL overheat. Simple as too much throttle going up a hill, and this WILL occur. Flooring it in these conditions just over-fuels it, and overheats it. It's NOT a petrol. Also, playing with the injector pump yourself to increase fuel exacerbates this problem.

I agree 110% on this one. Petrols and diesels are two completely differnt beasts, and there is definately a difference needed in driving style. The way i drive is to find the acceleration fringe and then back off a fraction. Revving diesels never really seems to help too much either.

bigbluemav wrote:The whole time I had the Mav', I don't think I revved it over 3000rpm!! Why? Cos' it doesn't need to! A n/a TD42 gets max at about 2000rpm.

Same here for me too - i don't rev my car over 3000 RPM in either N/A or turbo form. My dyno sheets show peak torque at 1370 RPM, and peak power at 2550 RPM when my GQ was N/A.

Exactly right!! Why the hell would you rev the crap out a TRUCK ENGINE?? The power and more importantly torque are developed SO LOW in the rev range, there is NO POINT in revving the crap out of it. If you want to rev, get a TB42/45/48!!

I am chasing this bastard of an issue as well, and currently running:

- PWR Radiator
- PWR 6x10 w2a intercooler
- High-flow thermostat (waste of time)
- All baffling back in place (ARB bar)
- Garrett BB turbo @16psi

This is on a '99 TD42T GU wagon.

Without the camper in tow, the needle doesn't move. Once towing there is long periods of heat build up and to say the AC cannot be used when towing.

I currently think it is the inter-cooler isn't up to the task. The front IC rad is sitting behind the XGT's and just isn't dissipating enough heat. So any sign of a hill and the intercooler starts storing the heat form the inlet air and stops doing its job. I need my EGTs under 350oC to use the AC, and under 450oC on a hot day to stop overheating.

I am in the process of replacing the w2a with a top-mount, anyone want a bolt-on PWR w2a kit?

- David.