AC blows Cold at idle. Cool when driving.

[ZehDuck]

My AC system on my FJ80 is blowing ice cold at idle, but when I drive down the road it gets warmer and just blows cool. I have had the system pulled down and the pressures were perfect. The system has a new dryer and new Evaporator. Thoughts? Thanks in advance.

 

[kruisinkid]

dead expansion valve, dead thermistor, failing compressor, old/tired/clogged condensor.

 

[ZehDuck]

I forgot to add condenser is also new. But the person I bought from did not replace expansion valve. I guess I'll start there and hope it's that and not a compressor.

 

[flintknapper]

Expansion valve most likely freezing up.

 

[ZehDuck]

Thanks.

I'll start there by replacing it

 

[RiverCityDave]

Air and moisture in the system causing freeze up. Once the system gets flowing at speed, it freezes up. You'll need to get it vacuumed and recharged, replace your drier, (it's a 12.00 part from RockAuto get the Denso, its OEM) and expansion valve (also Denso from RockAuto).

 

[ZehDuck]

i had the whole system vacummed by a reputable mechanic and a new drier, but the expansion valve wasn't replaced.

 

[RiverCityDave]

i had the whole system vacummed by a reputable mechanic and a new drier, but the expansion valve wasn't replaced.

Perhaps air was introduced during the charging process...The symptoms indicate freezing. It could be from a blockage in the system, or low pressure as well. Guages would tell the truth quickly. The FSM has a great section on diagnosing AC issues.

 

[BILT4ME]

Is your heater valve not all the way closed and you're blending HEAT into it? At idle, the circulation is minimal, while running down the road, there is more heat and circulation.

 

[jdayment]

What year is your truck? If its below 93 this might be worth looking at see if you can get Toyota to do the work.

 

[ZehDuck]

Hey guys. I changed the expansion valve today. It seems to have fixed the issue. It was only about 80 today though, so we will see if everything is good when it's mid 90s.

Thanks for all the help.

 

[kruisinkid]

please report back if it stays cold!! it helps others. glad to hear it.

how bad of a job was it? how much time you think it took? thanks!

 

[ZehDuck]

Taking out the condensor box was surprisingly very easy. It took probably 30 min to take out and another 30 to put back in. You do have to have a vacuum to pull down the system or take it to a mechanic. It's definitely worth doing it yourself.