A/C question

[Zaino guy]

Maybe this has been discussed before but when you turn on the a/c it blows hot for awhile. It happened on a couple of Mags I rented before buying mine so is this normal?

[Chic]

Maybe this has been discussed before but when you turn on the a/c it blows hot for awhile. It happened on a couple of Mags I rented before buying mine so is this normal?

I beleave all A/C blows the warm air out of the hoses first before being replaced with the compressed air.

[matpat]

Maybe this has been discussed before but when you turn on the a/c it blows hot for awhile. It happened on a couple of Mags I rented before buying mine so is this normal?

Every car I have had with A/C has blown hot air when first turned on.

[thewagon]

gotta double check this on my car because I could have sworn when I turned the a/c on, on a hot day, it didn't blow anything until it was ready to blow cool air.

[LouieLouie]

I just got mine fixed - there is a service bulletin, at least for the 06 SXT. I mentioned the hot air blast when I was in the dealership for an oil change and they looked at me like I was nuts. Then I got a call the next day from the service dept - part was ordered, to be covered under warranty. I don't have the paperwork with me, but I believe it said "replace A/C head unit"? It's been chilly here since I picked it up, so I can't say for sure if the problem is solved.

[Smokie]

Maybe this has been discussed before but when you turn on the a/c it blows hot for awhile. It happened on a couple of Mags I rented before buying mine so is this normal?

The A/C circulates thru the evaporator the air that is inside your car, if your car is hot, about 120 degrees sitting in the sun on a hot day with the windows close it cannot blow cold air when you first started.

The temperature drop across the evaporator is about 20 to 30 degrees, it also depends on fan speed, the fastest way to cool a car is max a/c on max fan speed and lower all windows a bit for a minute or so, outside air should be cooler than temp inside your car.

Once you have been driving steady for about 6-10 minutes the temperature of your a/c outlets should be about 40 degress, if is higher than that....you may have a problem.

[bigjim]

I had a few rentals that did this too, do the TSB.

The "HOT" he is talking about is the HEATER on full hot for a few seconds when you start the car! The rental I had in West Palm Beach had the issue so bad I would turn off the ac and heater when I got out of the car so I would not get pounded when I restarted it! It is more than the residual heat from the car sitting in the sun!

[Smokie]

I had a few rentals that did this too, do the TSB.

The "HOT" he is talking about is the HEATER on full hot for a few seconds when you start the car! The rental I had in West Palm Beach had the issue so bad I would turn off the ac and heater when I got out of the car so I would not get pounded when I restarted it! It is more than the residual heat from the car sitting in the sun!

You mean starting a car that already has a hot engine? Not from a cold engine start. Sounds like the heater core valve is open instead of close, bad valve or control.

[Zaino guy]

Sounds like the heater is it. I can start it on a cool morning after it sat in the garage overnight and for the first 7-10 seconds of a/c it's full hot. I thought it might be to keep the lines from getting mildewed or something. It has done it in 2 rental 300's, a rental SXT and mine. I difinately don't want to feel it this August. Get's almost warm here and it ain't a dry heat!!

[Smokie]

Sounds like the heater is it. I can start it on a cool morning after it sat in the garage overnight and for the first 7-10 seconds of a/c it's full hot. I thought it might be to keep the lines from getting mildewed or something. It has done it in 2 rental 300's, a rental SXT and mine. I difinately don't want to feel it this August. Get's almost warm here and it ain't a dry heat!!

You know your car better than I do; but unless your car has an electric heater it can't produce heat upon a cold start...if you do have electric heating....I learned something new today.

[iamkungfool]

HIJACK: My step dad said soemthing about thinking these new cars these days had Heatpumps in them...any ideas?

Sorry about the hijack

[Smokie]

HIJACK: My step dad said soemthing about thinking these new cars these days had Heatpumps in them...any ideas?

Sorry about the hijack

Heatpumps= reverse cycle. is not efficient when ambient temp drops below freezing, heatpumps are used in central a/c in the deep south only.

[iamkungfool]

Yeah i didn't think they'd go in cars. I live in MD and have a heatpump with elec backup (for when it drops below freezing). Please tell me MD isn't considered the deep south...if it is that'll be the 2nd time this week someone has tried to tell me i'm from the south...I'm going to cry now. good day

[Zaino guy]

You know your car better than I do; but unless your car has an electric heater it can't produce heat upon a cold start...if you do have electric heating....I learned something new today.

Wow, so did I! That your the mechanic here. Yea, it can't blow hot until the water temp is up...............

And yet, it does blow hot air for 7-10 seconds on a cold start. I withdraw my question, obviously I'm either imagining things or have no mechanical knowledge what so ever. Guess I'll have to tell my employer I caint work on them thar aeroplanes no mo.

[bigjim]

LOL, yeah my training from Chrysler years ago didn't teach me nutin. Even all that radar mechanic training in the Army that didn't teach me to observe neither! Any way, I am pretty sure the TSB or a good mechanic will take care of you. It should never default to hot when it starts.

Jim