minimal heat even when car is warmed up

2

2fastnotch

Member

Jan 20, 2008

61

0

7

Jan 21, 2008

#1

• Jan 21, 2008

• #1

ok guys ive own the same 89 5.0 lx like 3 times. the air coming out of the vents is not what i cansider hot, even after the car is warmed up. ive replaced the heater core. the temp guage goes like 1/4 of the way up. i would expect it to go higher but it never has. any ideas?

 

LiquidGT

Member

Oct 8, 2007

368

0

16

Near STL hell

Jan 21, 2008

#2

• Jan 21, 2008

• #2

My bet is you have a 180* or colder thermostat.

 

9

91foxbod50

Member

Sep 26, 2007

486

0

16

Jan 21, 2008

#3

• Jan 21, 2008

• #3

+1

 

2

2fastnotch

Member

Jan 20, 2008

61

0

7

Jan 21, 2008

#4

• Jan 21, 2008

• #4

when i replaced it the 2nd time i owned the car i replaced it with a 195 the highest autozone offered for it is there a higher one?

 

LiquidGT

Member

Oct 8, 2007

368

0

16

Near STL hell

Jan 21, 2008

#5

• Jan 21, 2008

• #5

They dont make anything hotter than a 195 for a mustang, its gotta be stuck open.

P.S. Are you saying you bought the same car back 3 times? So did the previous owner put a 180 back in?

 

Mustang5L5

That is…until I whipped out my Bissell

Mod Dude

Feb 18, 2001

43,258

17,941

224

Massachusetts

Jan 21, 2008

#6

• Jan 21, 2008

• #6

I assume the rad is full of coolant.



Feel the heater core hoses when the car is warmed up. Are both very hot?

If so, i'm willing to bet you have a blend door problem

 

NKau

Founding Member

Dec 15, 2001

1,346

0

37

Jefferson, WI

Jan 21, 2008

#7

• Jan 21, 2008

• #7

Mustang5L5 said:

I assume the rad is full of coolant.



Feel the heater core hoses when the car is warmed up. Are both very hot?

If so, i'm willing to bet you have a blend door problem

Click to expand...

These would be my first guesses as well. If neither is a problem, then I would suspect that your heater core itself is actually plugged. Had to help a friend flush one in a mid 90's blazer when it got cold here last week, and it made all the difference in the world.

 

2

2fastnotch

Member

Jan 20, 2008

61

0

7

Jan 21, 2008

#8

• Jan 21, 2008

• #8

thermostat is still the same one i installed. heater core is new coolant is full water pump is new as well. and yes i bought the same car 3 times. how do i fix the blend door ?

 

Mustang5L5

That is…until I whipped out my Bissell

Mod Dude

Feb 18, 2001

43,258

17,941

224

Massachusetts

Jan 22, 2008

#9

• Jan 22, 2008

• #9

Take the HVAC controls out and see if the HOT/COLD cable moves freely and see if it actually moves the door.

 

notch22

Member

Aug 24, 2004

22

0

17

Katy, TX

Jan 22, 2008

#10

• Jan 22, 2008

• #10

2fastnotch said:

ok guys ive own the same 89 5.0 lx like 3 times. the air coming out of the vents is not what i cansider hot, even after the car is warmed up. ive replaced the heater core. the temp guage goes like 1/4 of the way up. i would expect it to go higher but it never has. any ideas?

Click to expand...

I have the same thing happening with my car, only I havent owned mine 3 times. I thought it was my heater core and disconnected it. Now that I think about it, my temp gauge gets about halfway between cold and hot when sitting and idling, then goes down to about 1/4 way up when I start driving again. I'm thinking this is due to the motor speeding up and the water pump pumping faster. Knowing this, I would be willing to bet that the thermostat is stuck open. I may swap mine out this weekend and see what happens.

 

F

Fox8950

Member

Jun 29, 2007

247

2

18

Jan 22, 2008

#11

• Jan 22, 2008

• #11

+1 on the blend door but just as a piece of info the last 2 stangs I bought the previous owners had put the thermostat in backwards (most housings won't let you put them in backwards but these will) they will always run cold if they get stuck in backwards, just something that had happened to me thought if all else fails its something else to check at least.

 

K

krallman

New Member

Mar 3, 2006

96

0

0

Hurricane, WV

Jan 22, 2008

#12

• Jan 22, 2008

• #12

thermostat.

 

2

2fastnotch

Member

Jan 20, 2008

61

0

7

Jan 22, 2008

#13

• Jan 22, 2008

• #13

the thermostat is in correctly im thinking my fan clutch is going bad

 

black87ttop

Member

Oct 29, 2007

43

2

8

burlington,new jersey

Jan 22, 2008

#14

• Jan 22, 2008

• #14

clutch fan will not make it run cold, it would overheat if anything.
Oh and you the you probably have a 180* thermostat comment is bull *****.
we put a 160 in my buddys 91 and his heat is as hot as stock.
personally i wouldnt put a 160 in , but it was his car.
a good thermostat for our cars is a 180, car stays a little cooler without affecting the engine.

 

Mustang5L5

That is…until I whipped out my Bissell

Mod Dude

Feb 18, 2001

43,258

17,941

224

Massachusetts

Jan 23, 2008

#15

• Jan 23, 2008

• #15

I agree. I have a 180 in my car and it will roast me out on high.

The prob is elsewhere

 

Y

YETSRYD88LX

New Member

Nov 21, 2007

6

0

0

Jan 23, 2008

#16

• Jan 23, 2008

• #16

Check the blend door..I had this same problem...no heat but the hoses were warm. Flop the glove box down and look in at the blend door with a flashlight. See if you can open and close it by hand and then see if when you turn the dial it opens and closes. With mine the door was stuck and my dial wouldnt turn it, but then I opened it by hand and magically had heat. I have a 160 t-stat.