80 Series Diesel Overheating

Member - Ian replied:

garry
check your fan i remember seeing this problem before on this forum, you should be able to turn your fan by hand and feel a fairly firm restriction if not maybe your viscous coupling is faulty.
im sure if you do a search on here you will find the answer to your problem
ian Thumbs UpThanks 0

ROWDY replied:

Garry,
just long shot, but I have seen the impeller on the water pump corroded away with electrolysis, especially when incorrect coolant/water ratios are present. If the radiator has been removed previously and let dry out before refitting a lot of scale forms and this can block the tubes. A couple of my mates have experienced temperature fluctuations on long slow grinds and have fitted thermo fans on a manual switch to overcome the problem but I think it only masks the problem. Hope this has been of some help. rowdy Thumbs UpThanks 0

charl makssi replied:

greetings garry,


seems to be a common complaint. from my own expreience (gq 4.2 efi) i have had my temp dial read close to the red on two occations and both times the G train was working hard up hill on a warm day, i was concernd at the time but let it go, then upon my return i checked my nissan owners manual and it is within the manufacturers spec as normal range so before you loose your cool and wits check your owners manual it may save a lot of hassel and stress not to mention faith in the cruiser.



regards charl Thumbs UpThanks 0

truckster replied:

I too have been chasing up an overheating problem for 12months!

I have had the radiator flushed 2 times by radiator places, ended up replacing the radiator with a NEW 3 core, hoses, thermostat, Temp guage sender, Coolant HEAPS of times, and still on long slow climbs it overheats. in the snow the other week it STILL over heated on the long slow climb to the huts, and it was bucketing down snow at the time.. :(

You would be amazed how much of the radiator you **CANT** clean with a hose, the best bet is to remove it from the truck, and clean it out properly. Mine first time was blocked 25% on the outside, I thought hosing it out while on the truck was good enough, but its not.

Then turn it upside down, and stick the hose in what is actually teh lower hose mount, and flush out the radiator that way.

Ive been thru everything, and now about to replace the clutch fan, $300+ and then the only thing left is water pump at $400+!! Oh well if I do ever sort it out, I will have a complete cooling system rebuilt!
Also check out the 80series list, http://www.lcool.org/ they have a technical HELP page. Thumbs UpThanks 0

Tony replied:

Gary, I to had this problem with my Landcrusier, had the radiator re-cored, new thermostat, and replaced the fluid in the thermo fan (available through Toyota spares). I don't know which of the above was at fault but problem solved.

Tony.

Thumbs UpThanks 0

dave replied:

how's this for a chain of events.

Put in a NEW radiator shortly after fitting a turbo ~13 months ago. Had overheating (just under red) a couple of times over last summer. Took the truck back to the radiator place and asked them to check it out.

It seems that they only checked but did not replace the radiator, all fixed, 6 months of heat free motoring.... until last week.

Temp went up, coolant level went down, with the obligatory hissing and steaming. I limped to the nearest radiator place in the chain, had to top the radiator up twice to get there (with the engine running). Two hours later, resoldered top tank and no problems... until this week.

Quick run down the highway, temp started to rise, but not badly. and then the thing that really got me... I stalled the truck, now you know that there is something wrong with a diesel troopy if you can actually get the thing to stall, taken to friendly mechanic, running on 5 of 6 cylinders, guess what, cracked head.

Moral of the story, it odesn't matter how many times you replace, fix things, a 5mm split in a basicly new radiator will still bring you undone in a real hurry.

So the old girls gets a new (recon) 2H, won't know myself, just imagine all that power!!!!???

Dave Thumbs UpThanks 0

Steve replied:

Garry: had similar problem on mine and it turned out to be the Thermo Coupler on the fan... eliminated all other problems by replacing eveything else !! Cost a bit, and found everything else was in perfect condition !! Toyota dealer was as useless as you wouldn't believe... this all happened while on a long trip, so I couldn't get back to have a bite of him ! ( I replaced the whole unit !!) Thumbs UpThanks 0

Legend replied:

ten dollars or so invested in a new radiator cap wouldn't go astray either guys. Sounds simple but that and a new thermostat solved a lot of my problems earlier this year. Thumbs UpThanks 0

wherethefugawi replied:

I have 100 series just coming up to 48 months old and have just started (3 weeks ago) having temperature problems on warm to hot days at speed. At low speeds all okay
Thermostat and fluid in fan changed but did not correct problem.
Radiator removed (today 29/11/02) and top tank removed ..cores blocked with a sediment of somesorts??? Natrad Specialist cannot get a tube cleaner though tubes to remove residue.
Car has been serviced in accordance with Toyotas Schedule and requirements ( at least that is what I had booked it in for)

Heater core gave up the ghost 2 months ago. Could these two items be related?

Could this be your problem also?
Thumbs UpThanks 0