1995 Buick Lesabre Heater blows cool air below 90 degrees

Tiny
TMINER
  • MEMBER
  • 1995 BUICK LESABRE
  • 6 CYL
  • FWD
  • AUTOMATIC
  • 107,000 MILES
When I have the heat on I only get good heat when temp is set at 90 degrees. I replaced my intake manifold gaskets because I was losing water about a gallon every few days. I still am losing it at the same rate. I smell a strong odor of antifreeze when I open the door but not inside the vehicle. I have also replaced the radiator cap and the water pump. The water pump has a hose barb fitting very close to it and this was replaced with a metal one (which was plastic before).
Friday, December 11th, 2009 AT 7:15 AM

17 Replies

Tiny
BLACKOP555
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Do you notice any antifreeze leaks on the ground? Check for green or orange crud on the lines carying coolant. If you see that then that means its leaking where the green or orange gunk is.

Get vehicle hot and feel the heater core hoses. Are they both hot? One hot one cold. One hot one warm? Both cold?
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Friday, December 11th, 2009 AT 4:11 PM
Tiny
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I saw today that there is a big puddle of antifreeze next to the t-stat housing. The antifreeze is being lost at about a gallon a day. I filled up yesterday and the level is half way down my radiator today.
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Friday, December 11th, 2009 AT 5:14 PM
Tiny
BLACKOP555
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Since thers a puddle there you can run the car and take a flashlight. When the coolant evaporates turn off vehicle and wait. And you will see the coolant slowly turn they metal a darker color when it seeps out. Listen for hissing too. Sounds like you may need a thermostat housing gasket.
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Friday, December 11th, 2009 AT 5:20 PM
Tiny
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Still have heat issue but leak has stopped. The heat is fine when car is first hot but after awhile heater blows cooler air than what it is set on. Also found two vacuum hoses that were collapsed and worn out which we replaced.
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Monday, December 14th, 2009 AT 11:01 AM
Tiny
BLACKOP555
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Whats vaccum lines were they for? Next step is to feel the hoses when heater is putting out hot air. Then when it cools down check the temp again and note what you notice. Do both hoses cool down? Only one? Neither?
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Monday, December 14th, 2009 AT 9:25 PM
Tiny
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Check the temp on heater core hoses right? I will check on the vacuum hoses today and let you know what they are for.
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Tuesday, December 15th, 2009 AT 10:29 AM
Tiny
BLACKOP555
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Yes sir the heater core. They should be as hot as the upper radiator hose
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Tuesday, December 15th, 2009 AT 1:41 PM
Tiny
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The leak is back after 1 day of no leak. The t-stat gasket wasn't it apparantly. Where is the heater core exactly?
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Wednesday, December 16th, 2009 AT 9:43 AM
Tiny
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I don't know where heater core is but after t-stat was replaced there is still a leak and we've spent $600-700 on problem, I'm ready for this to be over. Where exactly is heater core?
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Monday, January 11th, 2010 AT 8:10 AM
Tiny
KHLOW2008
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Hi tminer,

Sorry for the delay in getting back to you. My fellow technician is away so I will try to assist you on this.

You can access the heater core via the engine compartment. The diagram shows the 2 hoses leading the heater core.


http://www.2carpros.com/forum/automotive_pictures/192750_Heater95LesabreFig05_1.jpg

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Monday, January 11th, 2010 AT 8:36 AM
Tiny
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Leak of about a half gallon a day:
Mechanic replaced plastic upper intake with a junkyard part (been told this is probably bad as well)
He replaced intake manifold gaskets

We have replaced radiator cap and put in the $30 Bar's Leak Head Gasket Repair copper looking fluid. We also replaced the t-stat and t-stat gasket.

We are looking into buying a new upper intake and replacing ourselves. Sorry, I will post today after work about heater hose temps. When heater is running now it will cycle from 90 degrees to cool air where before it would blow 90 all the time. 85 and below blows cool air 100% of the time. Also, engine runs rough now and oil pressure is low (just above red).

P.S. I donated more money and I will donate more if necessary. Thank you for the help.
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Monday, January 11th, 2010 AT 11:39 AM
Tiny
KHLOW2008
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Thank you for the donations, it is much appreciated.

I believe the problem is due to the coolant losses. When insufficient coolant is in the system, the heater would not work correctly.

With such a hugh amount of leaks, it should be easy to detect where the leaking is coming from.

Have you performed a pressure test to get to the bottom of the leaking source?
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Monday, January 11th, 2010 AT 1:20 PM
Tiny
BLACKOP555
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Sorry for the long reply the thing never poped up in my inbox!

To add on to kh's I agree with him. The vehicle shoudl be pressure tested to find the leak I am suprised your "mechanics" havnt done that. Once its pressured with air it will be easy to trace down the leak by ear and feeling for the air to be coming out.
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Monday, January 11th, 2010 AT 5:06 PM
Tiny
TMINER
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When heat is on the heater hoses are both very HOT.

Now, the excess fluid tank hose is very spongy and squishy and I believe it is not allowing the fluid to get to the radiator. When I added antifreeze/water to radiator, I then checked tank and the fluid level was quite a bit higher than the hot level when car was cold.

He did a pressure test on radiator but not on cylinders with piston at TDC. We will try to do that this weekend. We may do another radiator pressure test too after adding the Bar's Leak Head Gasket Repair Fluid. Should we also pull the plugs, do a pressure test on rad then crank engine (no spark) to see if fluid comes out a cylinder?
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Tuesday, January 12th, 2010 AT 11:25 AM
Tiny
BLACKOP555
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Yes pull the plugs that way if its leaking pas the headgasket you will hear it hissing. The pressure test on the cooling system should show you where the leak is at since your loosing such a alarmingly large amount.

The squishy return hose shouldnt matter since your loosing coolant theres no pressure in the system so its collapsing the hose.
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Tuesday, January 12th, 2010 AT 3:32 PM
Tiny
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Now for the past few days I haven't added coolant but I have to squeeze the overflow hose after engine is cool to get fluid over to refill radiator. The pressure isn't doing it on it's own. I am getting a suction sound when I remove the radiator cap though and when I do the fluid comes out the hole in the radiator the hose is connected to.

This morning the heater blew 90 for a minute then cool. I turned off heater then waited a couple minutes and turned back on and it blew 90 for another minute. I also smelled antifreeze for the first time inside the vehicle but I have no moisture on the flont floor like another car did when the heater core went out.
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Wednesday, January 13th, 2010 AT 8:12 AM
Tiny
BLACKOP555
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Wont always leak out depends on how fast its leaking from the core to cause that.

The coolant system isnt supposed to be filled up to the brim either when you turn it off. Unless its just been filled up. It will stay down a little bit. Nothign to worry about. But yes it sounds like that hose is collapsed and could need some replacing.

When the air is warm then gets cold do the heater core hoses get cold as well?
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Wednesday, January 13th, 2010 AT 1:30 PM

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