Getting hot with A/C on

[Gatti]

Hi,
As the title says my 2004 diesel Hilux has been getting hot when the air con is on. With it off in traffic conditions the needle sits just under halfway, but after I turn on the air con it creeps up to red, then if I turn it off it slowly goes to normal temp. Any ideas??

[john253a]

Is it an all of a sudden fault? Or something that has just gotten worse over time?

Check the temp with independent temp gauge, of engine at normal operating temp and then with A/C on.
This will determine were to go next.

If temp goes up as per gauge temp.
Check that the A/C fan is turning on when A/C is on,
Check for air restriction between condenser and radiator,
Check flow of radiator for internal blockages,
Check radiator cap for worn seal and correct pressure setting.

If temp goes up but not as per temp gauge
Check that the cable from A/C switch isn't fraied and causing stray current,
Check temp gauge, may be faulty and not reading correct temp.

[Gatti]

Thanks mate.

I have only had the Lux a couple of months and have just started to use the air con.

I will look at the things you have suggested

[jap]

The a/c fan? Do the diesels have a second fan?

Does the rpm pick up when the a/c kicks in?

Also as mentioned, i'd be getting the cooling system serviced.

[Gatti]

The revs do pick up with the A/C on.

I might just get a total fluid change done and get the problem looked at before camping season kicks in

[Swinny]

aswell the thermostat might be at fault aswell when under more load it over hears as the thermostat isn't quiet open....

[dave06]

I had similar trouble with my 99,changed my thermostat first still did it.Then I changed my clutched fan hub, it wasn't spinning fast enough, once i put the new one on was amazed at how much fan noise there was & how much more air it moved. Def try thermostat first only a cheap part. I can't remember what i payed for my fan hub though. good luck

[Ggn25]

common problem with "farm vehicles" , as they drive thru grass paddocks and get grass seeds and crap caught up between the radiator and condensor - this causes a flow issue. so if the a/c is turned on the extra heat created in front of the radiator can cause an increase in engine coolant temp.

common to have to remove the radiator and externally clean as well as the a/c condensor.
as noted there could be an issue with the viscous (clutch) fan coupling. if it is fairley free and does not spin up enough it will not help with the air flow. these are filled with special silcone oil to give the hub its viscosity. if the silicone oil has deteriorated it can be refilled without the expense of a total replacement . the hub can be removed and opened up with 6 or 8 phillips screws and just add some more silicone oil (dont clean out just add new fluid).

if this is the issue you can buy the fluid at your local dealer.. 08816-10001 is the part no. for a 10ml tube and coasts approx $14 each. now the complete hub could be $300 or $400 to replace.

cheers Tim

[Gatti]

I have had a look today. The radiator etc all look clean.

I had a look at the fan clutch, and when it's warm if I give at a push it only spins 1/4 of a turn so I think that's o.k.

I am leaning towards a stuck thermostat. If I remove the thermostat am I still able to drive it to see if it still gets hot, or should I stop being a tight arse and just replace it?

[jap]

Just buy a new one...i think the tridon part number for yours is TT281-180

[lux 70y]

Hey Gatti I have an 06 model Hilux and had all the same issues u have stated and had everything checked radiator, thermostat, fan, and mine turned out to be a temp sensor, it was giving a incorrect reading.. Once replaced guage has not moved and my aircon went back to super cold again..

[Gatti]

Is the temp sensor the one attached to the thermostat housing?

How much was it to buy? I might replace both

[Gatti]

Well my slight overheating problem continues...

So far I have flushed the system, replaced the thermostat, replaced the water temp sender and it's still doing it!

So today I ordered a new fan clutch, I scored one for $110 bucks, so I figured I'd just replace it instead of try and reco the old one.

Hopefully that fixes it! At least I know the cooling system will be good for a few camping trips during summer.

[jap]

If you got on the highway with the way it is, does it still overheat when you put the a/c on?
This may isolate whether it is an actual airflow issue

[Gatti]

It cools down once I get it moving, so no problems on the highway

[jap]

Probably the fan then lol

[danmcccc]

does your model use a heat conductive clutch fan like the D4D??? if it does then there probly no oil in the element and that makes the fan just not work at 100%

[Gatti]

I replaced the fan clutch today.

I then took 800kg's of rubbish to the tip and it didn't get hot, but on the way home I put on the air con and stopped at the lights in traffic and the bloody temp started to go up!!

Any other ideas???

[jap]

Get your radiator serviced.
Have seen ones on commodores with the bottom third full of shit before they start having issues.
Sometimes mechanic in a bottle doesn't cut it

[Horse]

My wasn't working the other day so cleaned out the filter then gave the radiator a good hose out.
Didn't look so bad but you should of seen the mud/sand that came out . Works as good as new now.