80 Series A/C Shut Down

Hi Matt
The 75 series with the same engine, 1HZ, displays the same characteristics.

If the temp gauge starts to climb the A/C shuts down or ceases to work properly.

Have no idea why, but doesn't seem to be any real problem as when the engine temp comes back to normal, the cold air starts to flow again.

Mate this is both common in Tojo and Nissan's so do not worry needlessly just drive easier.

Matt, it is a built in fault they have as protection

The A/C will cut out if you are driving too fast 125 km/h (or over 3000 rpm)

When the engine temp is over half it will also cut out.

Mine has never had this problem. Could it be the water Pump Or thermostat on the way out. Mine only gets to 1/4 unless heavy (soft) beach sand.

Matt

I have had the same model for 10 years now, and under no circumstances can I get the temperature needle to move upward. That includes 45 degrees plus heat pulling a van at the speed limit.

With your symptoms, I'd be getting someone to at least pressure flush the cooling system, replace the thermostat and test the viscous clutch (which despite what the Gregory's service manual says can be refilled with silicone) and see if that helps. I'd be prepared to be told that the radiator core is stuffed though - these beasts are getting pretty long in the tooth now and with all the radiator additives in the world eventually the radiator has to go.

But the back flush etc is a good start.

Keep us informed what happens

Max

You have a low diesel warning light on your sub tank? What model of 80 do you have? I have a standard and I don't have it, but think it would be really worthwhile!

First thing to check is the tension on the fan belt.

The temp will fall with higher revs cos the water pump is working harder at revs.

Owen

Hi Matt
If the temp is going up at cruising revs and then down again if you increase the revs, then it is time to put new silicon oil in the fan.
Go to Toyota get three tubes of the stuff open the clutch, drain the old, fill to overflow then seal it up. ( make sure it has no bubbles ).
An easy Saturday job.
Have fun

Craig

Hi Matt,

I had exactly this problem a short time ago in my 80 series 1HZ Diesel with aftermarket turbo.
My temp always sits about a needle thickness below half on the guage and never moves.
On a trip to Rockhampton and back with a tandem car trailer and a car on it my a/c cut out and 5 minutes later it started again. It took some time to realise that it was related to my temp guage fluctuating. Whenever it hit halfway on the guage which is only about 2mm higher than where it normally sits, the a/c would cut out.
As mentioned above mine turned out to be the viscous fan hub. It started like this and only played up intermittently but using a process of elimination I isolated it to the viscous hub.
I fitted an aftermarket hub from Rawlinson's Toyota Specialist for $110.00 and have done some very heavy towing in hot weather since and have had no more problems. And that includes long highway runs in hilly country where the turbo has really been working hard. All of these miles I have had the A/C turned on and it has never cut out since. I was not keen on drilling holes in the original hub and filling it with more silicone and a genuine toyota hub was $185.00.

I hope this helps mate.

Cheers,
Brett

We never had this prob but never really had it working until after the radiator was replaced with a bigger beauty.....still never have that prob....i would say its just a safety thingy.....

Laura

Thanks for the reply's everyone. I was only doing 95-100 in fifth or fourth so I wasnt exactly flying, I also had the same problem when towing my van. I might try a new viscous clutch. The temp dosent normally move at all during normal driving, just over 40degc days when heavily loaded or when towing the van. I will try the new clutch and juve the radiator a flush too. The radiator looks pretty good(car is a 97 with 150K) so I just go with the process of elimination. Cheers
Matt