Overheating when AC on?

[Chopz]

So pretty warm day in Perth today about 37C.

Driving home from work down the freeway I had my AC on and noticed the air wasnt blowing cold anymore just seemed to be blowing air, looked at my temp gauge and it was up near the H.
I turned the AC off and and kept driving, but cautiously to watch the gauge and its seemed to drop back down to normal which is roughly half way.

Ran home without the AC on and it seemed ok.
Any suggestions what this could be please guys, before I again lose a days wages and head back to the dealer to get them to fix it, or attempt to fix it only to tell me its not covered under warranty and now I have to pay for the labour myself........I hate dealerships.

 

[Old.Tony]

The air conditioning system is designed to cut out when the coolant temperature exceeds a predetermined level. I don't know the exact temperature, but I do know that the cooling system goes into full swing at 105c. At some point beyond that, the aircon is turned off by the ECU regardless of the state of the switch.

I would be looking at the cooling fan to start with. The coupling is supposed to drive the fan quite hard when it's hot, and if the coupling has worn it's possible that the fan is turning over at a rate that doesn't provide sufficient airflow.

 

[04SilverSTR]

What he said^^ what car is it and how old?? check the fan, also check the radiator and a/c condensor as well for mud and shit!!

bryan

 

[scottybobcat]

what they both said

 

[Chopz]

Its a 2005 D22 ZD30 Dual cab

I had a mate who also said to check the viscious fan if I'm right, how can I check it to see if its worn or not, anyway at all?

 

[Old.Tony]

In the morning, go out and spin the fan before you start the engine. It should move with little resistance and it should be smooth to turn - no gritty feel.

After driving it and getting the engine nice and warm, pull over and turn off the engine. Try moving the fan again - if the fan still moves fairly smoothly with little resistance it's stuffed. When hot, it should be very hard to move at all.

If it doesn't come up to those standards, the coupling needs to be replaced.

 

[Chopz]

Thanks Tony your a godsend mate, another stinker in perth today so I'll see how it goes

 

[tweak'e]

when cold the fan should be smooth to turn but it should not spin freely. give it a flix and it should stop within half a turn or so.

 

[FatBoy89]

Lubricate your cv splines

 

[Chopz]

Ok so its spins relatively freely like tweake described when cold, no gritty feeling all smooth.
Took it for a drive and got it too its normal temp (drove around a bit today and doesnt seem to be getting hot like it did yesterday) however turned it off and popped the bonnet and gave it a spin again, it still spins the same as when cold, if not more freely actually. Suggestions?

 

[tweak'e]

sounds ok. fan won't be hard to turn till its really really hot.

i would check radiator and aircon is not blocked up with leafs etc. check radiator water isn't rusty etc (or other internal blockage).
otherwise thermostat maybe starting to fail.

 

[Dave]

When was the last time the coolent was changed ?

Radiator full of mud or condensor.

 

[scooba_285]

Also could have even been the termostat got stuck then freed itself, I've has it happen in my Subaru same symptoms

 

[Old.Tony]

Ok so its spins relatively freely like tweake described when cold, no gritty feeling all smooth.
Took it for a drive and got it too its normal temp (drove around a bit today and doesnt seem to be getting hot like it did yesterday) however turned it off and popped the bonnet and gave it a spin again, it still spins the same as when cold, if not more freely actually. Suggestions?

As others have said, I'd get the engine quite hot. My "nice and warm" was a little conservative. Give it some grief up a long hill and stop at the top and try the fan.

If the engine is really hot and the fan still turns over the same, the coupling is shot. I'm not sure if they can be rebuilt.

There's a lot of merit in doing a radiator flush too. Make sure you get your hands on some good coolant too.

 

[Krankin]

is the thermo out front working??

as well as the the other posts, get the cooling system tested and the ac system checked out

 

[Chopz]

I've managed to narrow it down too hot days and long hauls.

Driving around day to day, no problems at all, but when we have a 37 degree day like we did yesterda and I'm on the freeway sitting on 100-110 it seems to start then. More if I give it a bit too overtake someone, then it gets up there.

Bit of a noob question but would an intercooler help keeping engine temps down at all?

 

[Old.Tony]

Indirectly, a little, nothing major in it though. The intercooler reduces the intake air temp and that will cause the combustion temp to be a little lower, but combustion is still combustion so the temps are still going to be high (600C+ at the exhaust port). That's way higher than where your temp gauge normally sits (91C) or where the cooling system comes on strong (105C).

 

[Krankin]

looked at my temp gauge and it was up near the H.

that reading is probably still in an acceptable range and considering the driving conditions

 

[petes navstr]

So pretty warm day in Perth today about 37C.

Driving home from work down the freeway I had my AC on and noticed the air wasnt blowing cold anymore just seemed to be blowing air, looked at my temp gauge and it was up near the H.
I turned the AC off and and kept driving, but cautiously to watch the gauge and its seemed to drop back down to normal which is roughly half way.

Ran home without the AC on and it seemed ok.
Any suggestions what this could be please guys, before I again lose a days wages and head back to the dealer to get them to fix it, or attempt to fix it only to tell me its not covered under warranty and now I have to pay for the labour myself........I hate dealerships.

I've managed to narrow it down too hot days and long hauls.

Driving around day to day, no problems at all, but when we have a 37 degree day like we did yesterda and I'm on the freeway sitting on 100-110 it seems to start then. More if I give it a bit too overtake someone, then it gets up there.

Bit of a noob question but would an intercooler help keeping engine temps down at all?

mine was doing exactly same thing, driving to yarrawonga a few weeks ago on a 40+ degree day with my dirt bike in the tub and i was towing a double jet ski trailer with one jet ski on it sitting on Hume f way doing 100-110klm with air con on and air con cut out then temp gauge went full hot and flashing engine light came on os i pulled over and it took shit loads of water to fill radiator, since then its over heated one more time in Geelong few days ago so took it to radiator place and he pressure tested a few times he said and said its all fine he cant find nothing wrong .. i know its not though cause i picked up car friday afternoon and checked radiator level on sunday b4 i started car and it took 1 litre in radiator already, so i would assume a litre every 2 days is not normal????
so I've left it idling for 45 min with air con on and it didn't over heat
the thermo fan does kick in -
thermostat was changed last year (6months ago)
checked engine fan while its cold and it spins good but not freely or rough-

i dont know what else to check???? i cant see coolant dripping anywhere either??
maybe another radiator place might pick up the problem

 

[bods]

try your radiator cap. If you havent changed it already id try that as it wont let the system pressurise properly if its had it.