Turn on A/C, car gets hot....

The Green GT

No 13 year olds are safe around me.

10 Year Member

Jan 8, 2006

1,269

19

99

Louisiana

May 6, 2007

#1

• May 6, 2007

• #1

So when i turn on my A/C, my car gets hot. A/c is a thing you need down here in LA too. I am pretty sure my high speed fan is coming on too. But Ill check it tomorrow, and possibly wire it to a switch if needed. the pump and coolant was changed pretty recently too.

What do you think?

EDIT: And its getting hot at a constant cruise @ 75 MPH turning like 2500 RPM. Not exactly dogging it. :/

 

HISSIN50

"How long does it take to get help in here?

15 Year Member

Nov 29, 1999

31,179

33

129

May 7, 2007

#2

• May 7, 2007

• #2

It sounds like a simple heat rejection issue (read that if you have the air dam under the car, the radiator cannot reject enough heat). The condenser puts extra heat into the radiator (due to the condenser sitting in front of the radiator). This makes the radiator less efficient (less temp delta between coolant and ambient air across the coil, so the cooling system temps phase shift due to the hotter ambient air across the coil).

Now if you can report how much hotter, that could help. And if it gets hotter while going slowly or stopped, you could have a high speed fan issue (as was my case. A/C only kicked low speed on. ).

Good luck Eric.

 

The Green GT

No 13 year olds are safe around me.

10 Year Member

Jan 8, 2006

1,269

19

99

Louisiana

May 7, 2007

#3

• May 7, 2007

• #3

210* is my normal temp. When I turn on the A/C it will be up to around 230* in a matter of minutes. Then if I cut the A/C off, it takes about 15 minutes for it to go back down to 210*, then if I cut it on again, it shoots right back up.

And this is with the fan on low, middle knob @ 9 0'clock, and Norm A/C. I would hate to see what MAX A/C would do.

I really need to get another air dam. Ill try that, and if no dice, Ill wire the fan to a switch.

EDIT: It will get hot no matter where Im at, or how im driving. It just gets a little hotter if Im in stop and go traffic. But not much.

 

HISSIN50

"How long does it take to get help in here?

15 Year Member

Nov 29, 1999

31,179

33

129

May 7, 2007

#4

• May 7, 2007

• #4

Max AC shouldnt affect it. All MAX does is pull air from inside the cabin and recirculate it. This is the way to go once your cabin is cooler than the outside air.

I actually have the feeling that it's a radiator issue (it cannot reject enough heat, and the AC is putting it over the top). That is, unless you run a stock t-stat or it's retardedly hot in LA already (we flirt with triple digits later this week. ).

With the air dam, on the highway you should be a few degrees over the stat rating if the radiator is capable of rejecting all necessary heat, and it's getting as much air flow as is possible.

Good luck.

 

Bosko5.0

Active Member

May 18, 2006

1,067

0

37

longwood, FL

May 7, 2007

#5

• May 7, 2007

• #5

did you make sure your condenser is not blocked with debrisand or other things

 

go-stang5.0

New Member

Jan 27, 2003

2,244

0

0

Glenview,Il

May 7, 2007

#6

• May 7, 2007

• #6

How recently was the coolant changed? Could there be air in the system? Have you checked to see if there is any debris on the radiator, plastic bag, cardboard, etc. Basically anything that would prevent convection from part of the radiator. Or have you driven anyehre dirty lately? I'd check for large debris and also wash off the radiatior with a gentle mist of water..high pressure water may damage the fins so dont do that. Or could this be a prelude to the t-stat going bad?

If your car w/o the air dam didn't do this before at high speed then it woulden't start doing it now unless something happend/changed. Also, if its over heating at high speed then its obviously not a fan issue, cuz the fan shouldent need to run at 75 mph.

 

The Green GT

No 13 year olds are safe around me.

10 Year Member

Jan 8, 2006

1,269

19

99

Louisiana

May 7, 2007

#7

• May 7, 2007

• #7

If you squeeze the upper rad hose, should I be able to hear my t-stat moving? I know when i took the neck off to tap it for my was temp gauge, the t-stat was in 4 pieces.

As far as anything like a bag being in there, nothing. Only thing in there is bugs and crap. I guess Ill clean it, but its not bad enough to cause it getting hot like this.

Coolant was changed Id say around December. I had a busted pump and changed the entire thing. I didnt burp the system though. But I didnt completely drain it. I also parked it on an incline while filling it and let it run untill I wasnt getting bubbles. And it hasnt overheated before, so Im sure thats not the problem.

Looks like ill be getting that Summit radiator soon.

 

Bosko5.0

Active Member

May 18, 2006

1,067

0

37

longwood, FL

May 7, 2007

#8

• May 7, 2007

• #8

the tstat is one piece.

 

The Green GT

No 13 year olds are safe around me.

10 Year Member

Jan 8, 2006

1,269

19

99

Louisiana

May 7, 2007

#9

• May 7, 2007

• #9

Im thinking I migvht have another broken t-stat. Same thing happened last year. This time Ill be getting a Mr. Gasket.

But a broken t-stat wouldnt cause this right? All the pieces were there from the last one, and it did it last year about this time too.

 

HISSIN50

"How long does it take to get help in here?

15 Year Member

Nov 29, 1999

31,179

33

129

May 7, 2007

#10

• May 7, 2007

• #10

If the t-stat is broken, all bets are off. You have no idea how little or much flow there is. While a cooling system is a closed loop, I can see an issue from coolant moving too slow due to a blockage.

 

The Green GT

No 13 year olds are safe around me.

10 Year Member

Jan 8, 2006

1,269

19

99

Louisiana

May 7, 2007

#11

• May 7, 2007

• #11

So it should NOT make noise when i squeeze the hose then?