Landcruiser overheating

Tell your mate to give the radiator and the a/c condenser a good external hose out Dust;grass;bugs etc build up over time

This may be of some assistance.My 80 series started to overheat,so mechanic did all the right things,still overheating(according to the gauge).Fitted a proper temp.gauge temporarily -no overheating.Apparently there is a fault with the fuel gauge which causes the temp. gauge to malfunction.The problem was solved by replacing the FUEL gauge-no more problems.Not saying this is the cause of your overheating.but it was with my vehicle.My mechanic was told that this was a fairly commom problem with some 80 series by one of the local auto-electricians.This may sound a bit far-fetched but I thought it may be of some help.
Cheers,Mick.

Hi Kroozer Souds very mutch like radiator is either externaly blocked with grass seeds etc, or internaly blocked cores flushing will not clean out core radiator needs removing , top tank removed & cores roding to clean them radiator places do this. What you described sounds like partly blocked radiator NOT faulty gauge. Cheers Daryl

Hi Kroozer

If fuel injectors are faulty and either under fueling or over fueling they will make that piston run hot.

Found this on site talking about fuel injectors.

David

Hi Kroozer,
Don't know if you've tried already, but you could have a look at the LCOOL site,(Land Cruiser Owners On Line), the LC gurus may be able to help. Just type LCOOL into Google.

Rob

I'll assume there is no aftermarket turbo.

On my daughter's 1Hz, we didn't realise we had a problem until we fitted a TM2 that constantly measures temperature. First thing we found out was that the temp gauge stays steady with the needle in the middle from about 60 to 95 degrees - Toyota build in a "flat spot" so the driver is not bothered by fluctuations. So you may find that the temp is actually up when you're cruising at 100kph too.

We decided to check everything.
#1 Pulled the radiator out and we found dirt and grass in the fins of the radiator (but nothing was not visible from the front as the A/C Condensor had been cleaned). We cleaned this out.
#2 Sent the radiator to the shop and had the top tank removed and the radiator rodded - it was 60% blocked (cost $130)
#3 Removed the thermostat, sat it in the saucepan of water on the stove and measured the temps at which it opened - should start to open at 76 deg and fully open at 90 deg. This one was opening 5 degrees too high, so we bought a new thermostat from toyota (cost $30 - cheaper than supacheap!)
#4 Removed the thermofan - dismantled it and checked it for the viscous fluid. this one actually had plenty, but you can buy an 18ml tube of the stuff from Toyota and refill it if you need to (costs $13 a tube).
#5 We replaced the water pump as well because we were there - but this is the least likely cause of overheating.
#6 flushed the block and heater in both directions.
#7 new hoses and belts.

So we had 4 causes of the overheating, and if I had your problem, I'd do the same checks.

The 70series have little radiator space and with the 75series, not a lot of space for airflow under the bonnet. So driving lights, some bullbars and even dual batteries and other accessories reduce the airflow under the bonnet.

Cheers
Phil

Go to a radiator place and have the radiator and engine power flushed out . Costs me $150 every year . Never had a overheating problem with the 1HZ.

If the temperature rises and falls like you say, I would start with the viscus hub at the fan, this may be as simple as putting some viscus hub oil in it.

Cheers Steve.

first thing of all I would do is install an aftermarket temperature gauge to find out there is actually a problem and how bad it is.
Standard gauges are not linear and hence I doubt it is going from running fine at 90 to overheating at 95.
They are designed to sit in the middle til outside certain parameter then move.

Very good tips above, you may find that the bottom radiator hose is sucking in.

Cheers

hi kroozer
after 304,000 it would be time for a professional radiator clean bill.

Something no one has mentioned and Im not sure if it applies to your model.

In a 100 ser 1HZ if the motor gets hot the A/c cuts out, done by a sensor near the radiator.

Maybe yours has been disconnected.


Just a thought

Kroozer
Had same problem with 75 series, did all of suggested ideas , still had issues .The bonnets seal too well with rubber strip preventing escape of hot air ,causes batteries to fail before time [toyota placed insulated covers around battery and put vents out the side through the gaurd], I put a 4mm spacer between bonnet and bonnet hinges and allowed hot air to escape , you could the diesel rattle more easily but small issue to have a cooler motor .Toyota did not have this problem before the 75 series came out in late 1984 , the previous model had vented bonnets and no rubber sealing strip .At the same time I had a 60 series factory turbo , no issues due to bigger radiator , different shape under bonnet due to full width bonnet over wheels therefore different air flow characteristics. Over the cooler months I would remove spacers ,I did have to instal extra bracing around captive nuts as cracks showed up after 3 summers , the area I live is western NSW and many days are above 40 degrees , the vehicle was a work truck and was not spared , fitted with bars etc. I even moved the Super Oscars to above the roof to assist airflow
Best of luck Mick

Excellent, thanks everybody for your input. Seems it could be one of a million things or all of the above. Will let him know and he can decide what way he wants to go with it. I personally would fit the aftermarket gauge as mentioned first, then start a process of elimination. Probably pay just to buy a new fan, fit new hoses and get radiator done by pro, then see what happens.

Again, thanks all didnt expect to raise so much interest and get so many great results.

Cheers

Hi Kroozer

Same prob 1hz overheat on hills of higher speeds

Put in TM temp, and confirmed.

Had new rad, and hoses so not that.

#4 Silicone Fluid into viscous coupling and problem went away

evan at highway speeds the fan helps
Cheers

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