Overheating Troopy

I have a 75 series 92 mod diesel ute, also with an after market turbo. From what I was told the owner of it before me (Im 2nd) had the turbo fitted (Motson??) from basically new then towed a van around Oz - best thing he ever did for it as it still goes like a rocket 275k later! (Had since 115k)

Getting back to the point, it over heated on him as well and am sure he got a bigger 3 core radiator fitted to it. Know it only overheats on long hauls up or working hard in the sand towing, as I am currently on a trip around Oz towing a CT.

My suggestion is get another opinion on the radiator.

Is it a 2H or a 1HZ & does it have a oil cooler.

Have you got an exhaust gas temperature gauge to measure the exhaust temps produced by the turbo? If not, and your exhaust temps post turbo are over 550 degrees C then this is a common problem for overheating of diesels.
Get a gauge fitted, "thermoguard " an adveriser on this site make one and then you can really start to accurately gauge what exhaust temps you really have and drive your vehicle accordingly. If your cooling system is in good condition then this is probably where you need to go next.
Regards Andrew.

How long since the thermostat was replaced? If it's been a while replace it but consider one that opens at a lower temperature.

The water pump impeller blades may be rusted away too - but that's the extreme. Seen some pumps that were nothing more than a disc to try and push the coolant around. It was nothing more than the coolant thermo-syphoning around the system to try and keep cool.

Don't overlook the radiator hoses - they too will collapse and restrict the coolant flow under load / heat. Hence the reason some have the wire spring in them to prevent this from happening.

Last is the radiator - again get a 2nd opinion or even remove it yourself and get a clean out. Make sure the radiator cooling fins are not deteriorated either as these help with the cooling.

While the outside of the radiator may look clean aqnd be able to be seen through it is amazing how much crap can get stuck in it externally, never mind the internal blockages.
Troopies especially 2H powered ones do run hot as at road speeds, 80 -100kph there is bugger all airflow in the engine bay in standard trim BEFORE the bullbar, winch, driving lights, bug screen and anything else is fitted to the front further restricting airflow. Never mind the extra heat from a turbo, that is why the last 2h powered ones had an extra grille on the passengers side and a box around the battery to stop it cooking.
My NA 2H powered troopy would run hot in summer, on one trip out west in Sept I removed the grille and badge which enabled it to cope as long as I stayed in 4th gear rather than 5th. The rad had been serviced/cleaned every year before long trips too.

Hi Kristy,
After numerous checks, my overheating problem ended up being the thermostat. This was the first thing that was checked and it was opening up, obviously not opening enough. But keep the following fact in mind:

Exerpt from a well known turbo supplier -
"REMEMBER THIS DIESEL SAYING- ‘Rich is Hot (more Fuel)….Lean is Cool (less Fuel)!!
Fact- It‘s simple physics. Pressure and volume are relative to each other. A turbo running higher boost gets higher volumes of air to an engine than the one running lower boost. The higher the boost the more air volume! A turbo is only an air supply device. Boost pressures used in turbo charging are relatively low and don’t generate much heat if any. If we kept compressing the air to a couple of hundred PSI though, air would soon heat up. It still stands that fuel makes the heat in the
equation!! Loads of fuel means loads of heat. A correctly matched turbo spins up fast so as to keep a nice lean mixture down low and to get a torque increase early in the rev range (a lean mixture is cool and clean in a diesel!!). As we know, diesel engines produce maximum torque at low engine revs so we need a turbo to be at maximum boost at those low engine revs. What's happened now to the ‘large low revving turbo‘? Not much, until the engine revs get up high. Too late for the boost to arrive at high revs! In fact if the boost is kept low and the turbo spins up slowly, the fuel and air mixture can be quite rich in the low to mid working range of the engine. ‘Rich means heat in a diesel‘. That’s why using a large ‘cool’ turbo charger is a fallacy! With the high revving diesels of today, a turbo needs to boost early and hold the boost through the large rev range. "
Regards.
Frank

I know the problem. Drive you crazy. I went through every option I could think of apart from replacing the motor. I've got two 75 series cruisers. The Supa Trupa and a trayback. Under heavy load towing and loaded down the 2H trayback never over heats NEVER! The Supa Trupa ALWAYS overheats on any hot day or up a hill or standing in traffic.

Well... I finally decided that it had to be a micro crack in the head and had that done.. cost mega-bucks. No use. ....
I even considered putting a little radiator further back underneath the body, mounting a electric thermofan and a water pump to feed it. I was going to incorporate so much damn copper piping that simply the volume of coolant going through the system would keep the rotten thing cool.... I was gunna... I was gunna.... then the motor died!

So I'm currently fitting a 1HZ motor with matching gearbox..... yep replacing the motor.

ps.. the Supa Trupa was turboed DTS, but overheated before and after. I'm planning a trip up the middle to Darwin later this year.. October... should be hot enough to try out the new donk.

Oh what a feeling! Well couldnt help that one!
Would an oil cooler help? My ole TD Triton has an engine oil cooler, standard I think, & never had any signs of overheating & rarely top up the coolant. Maybe thats the answer, maybe not!

One option may be to look at one of those electric water pumps advertised in 4WD Monthly. They automaticaly adjust coolant flow based on water temperature. The editors little suzi with the holden V6 donk uses one with good results. One of these with a higher volume radiator may be the answer.

As for the gentleman who mentioned Exhaust Gas Temperatures (EGT), He is right. Most fuel injection mobs should be able to do a test on a dyno for that.

Had the same problem Kristy. You should be aware that the temp guage always should be about half way as well.
My solution was to replace the radiator, hoses, thermostat , recon the fan coupling and had it done by a good, reputable workshop (if you're near adelaide, it's in holden hill).
After some $700, it now works fine and has never missed a beat towing my camper trailer anywhere in any heat.
I have bullbar and lights fitted as wll and now the problem is solved.

Overheating 75 series with aftermarket turbos commonly get discussed.
Check thread 20572.
As I understand it, a bigger, better radiator helps.

BTW if yours is a '91 model it will have the 1HZ.

Also out of interest, the factory TD 79series have not had this problem. Had mine in soft sand at 40 degrees at the weekend without the temp gauge moving. I know they have a bigger 3-stage fan as well.

Cheers
Phil