Thermostat?

Tiny
BOWTIEBLAZER04
  • MEMBER
  • 2004 CHEVROLET BLAZER
  • 6 CYL
  • 4WD
  • AUTOMATIC
  • 120,000 MILES
So my blazer has no heat with the blower on. I wanna say I smell I faint smell of antifreeze in the vents. I am not losing any antifreeze though I check it both hot and cold. T stat is under a year old.

Engine is running normal temp all the time.
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Sunday, January 31st, 2010 AT 10:54 AM

32 Replies

Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 108,005 POSTS
Is the engine running at a normal operating temp? Also, with the engine hot, running, and the heater on high, do both heater core hoses are hot?

this guide will help walk you through the steps of changing the thermostat with diagrams below to show you how on your car.

https://www.2carpros.com/articles/replace-thermostat

Check out the diagrams (Below). Please let us know if you need anything else to get the problem fixed.
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Thursday, February 4th, 2010 AT 1:42 PM
Tiny
BOWTIEBLAZER04
  • MEMBER
  • 4 POSTS
Yes the engine is running at nromal temp and no the hoses are not getting hot.

Antifreeze is clen to by the way
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Thursday, February 4th, 2010 AT 5:08 PM
Tiny
MIKE BUTZNER
  • MEMBER
  • 1 POST
  • 2003 CHEVROLET BLAZER
  • 6 CYL
  • 4WD
  • AUTOMATIC
  • 91,000 MILES
Where is thermostat located on the car
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Friday, September 11th, 2020 AT 3:26 PM (Merged)
Tiny
MASTERTECHTIM
  • MECHANIC
  • 4,749 POSTS
Follow the upper radiator hose to the engine. where it connects is the thermostat housing on the intake manifold. Here is a guide that will walk you through the repair with instructions in the diagrams below to show you how on your car.

https://www.2carpros.com/articles/replace-thermostat

Check out the diagrams (Below). Please let us know if you need anything else to get the problem fixed.
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Friday, September 11th, 2020 AT 3:26 PM (Merged)
Tiny
PMARTIN60
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  • 1 POST
  • 2003 CHEVROLET BLAZER
  • 6 CYL
  • 4WD
  • AUTOMATIC
  • 79,800 MILES
My car runs 210 degrees down highway if u turn it off and restart temp rises to 230 and slowly cools down. I have changed thermostat an flushed and added new coolant. Any suggestions?
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Friday, September 11th, 2020 AT 3:26 PM (Merged)
Tiny
MHPAUTOS
  • MECHANIC
  • 31,938 POSTS
HI there,

Thank you for the donation.

The first thing to remember is that when the engine is turned off it becomes a heat sink and the cooling system naturally rises in temp, many European cars have fans that will activate with the ignition off and often you will hear them cycle when the car is off. I would get the radiator cleaned & flow tested by a radiator repairer, check that there is no excess build up of leaf litter around the base core of the radiator restricting air flow and check that cooling fans are drawing good air.

Mark (mhpautos)
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Friday, September 11th, 2020 AT 3:26 PM (Merged)
Tiny
REDZFAM
  • MEMBER
  • 2 POSTS
  • 2003 CHEVROLET BLAZER
  • 6 CYL
  • 4WD
  • AUTOMATIC
  • 60,000 MILES
I replaced the thermostat and refilled the antifreeze. It gets warm when the RPM's are up but when I come to a stop light it goes cold
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Friday, September 11th, 2020 AT 3:26 PM (Merged)
Tiny
ZACKMAN
  • MECHANIC
  • 4,202 POSTS
Easy way out is to press the "Recirculate" button. The proper way is to perform cooling system flush to remove build up and sludge from the heater core. And make sure to refill with 50/50 mixture of coolant/distilled water, not tap water.
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Friday, September 11th, 2020 AT 3:26 PM (Merged)
Tiny
MUNROFAMILY
  • MEMBER
  • 1 POST
  • 2003 CHEVROLET BLAZER
2003 Chevy Blazer 6 cyl Two Wheel Drive Automatic

How do you drain the radiator (below thermostat housing) as this is step one to replace thermostat. I have not a drain on the bottom of the radiator have I missed it.
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Friday, September 11th, 2020 AT 3:26 PM (Merged)
Tiny
BLUELIGHTNIN6
  • MECHANIC
  • 16,542 POSTS
It is located on the passenger side of the radiator near the bottom edge, on the engine side. You might have a small black rubber hose coming off of the area of the drain. The drain is plastic and should look kind of like a wing nut. You also get the best access to it from inside the wheel well by removing the pastic fender well cover.
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Friday, September 11th, 2020 AT 3:26 PM (Merged)
Tiny
LINDASBLAZER
  • MEMBER
  • 1 POST
  • 2002 CHEVROLET BLAZER
  • 4 CYL
  • 2WD
  • MANUAL
  • 82,000 MILES
My car keeps running hot then the heater kicks in and it goes back to normal, then the heater shuts off and it happens over and over. It is WAY to cold outside and I need to get this fixed, but am on a tight budget so I would like to try to replace the thermostat first to see if that is the problem. Would anyone please help by telling me how to do this on a 2002 Blazer?
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Friday, September 11th, 2020 AT 3:26 PM (Merged)
Tiny
DENNYP
  • MECHANIC
  • 1,824 POSTS
Engine Coolant Thermostat Replacement (4.3 L)
Removal Procedure
Partially drain the cooling system. Refer to Cooling System Draining and Filling .
Remove the air cleaner outlet duct. Air Cleaner Outlet Resonator Replacement in Engine Controls - 4.3 L.

Remove the throttle body bracket nuts and reposition the bracket.

Remove the water outlet housing mounting bolts.

Remove the water outlet housing from the lower intake manifold and set aside.
Remove the gasket or O-ring.

Remove the thermostat.
Clean all the sealing surfaces of the water outlet housing.
Clean the sealing surface on the lower intake manifold.
Installation Procedure

Important: In order to prevent leakage, thoroughly clean all parts and sealing surfaces.

Install the thermostat.

Install a new gasket or O-ring.
Install the water outlet housing to the lower intake manifold.

Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

Install the water outlet housing mounting bolts.
Tighten
Tighten water outlet housing mounting bolts to 19 NÂ m (14 lb ft).

Install the throttle body bracket to the throttle body.
Install the throttle body bracket nuts.
Tighten
Tighten the throttle body bracket nuts to 10 NÂ m (89 in lb).

Fill the cooling system. Refer to Cooling System Draining and Filling .
Inspect for coollant leaks.


https://www.2carpros.com/forum/automotive_pictures/102900_1_3.jpg



https://www.2carpros.com/forum/automotive_pictures/102900_2_3.jpg



https://www.2carpros.com/forum/automotive_pictures/102900_3_3.jpg



https://www.2carpros.com/forum/automotive_pictures/102900_4_3.jpg

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Friday, September 11th, 2020 AT 3:26 PM (Merged)
Tiny
DGRIMM2
  • MEMBER
  • 1 POST
  • 2002 CHEVROLET BLAZER
Engine Cooling problem
2002 Chevy Blazer 6 cyl Four Wheel Drive Automatic

I changed the thermostat in my car, temp is good and heat is great, but still seem to have a leak or something towards the bottom of the radiator, is there a pressure release valve or something I need to check? The leak is on the drivers side.
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Friday, September 11th, 2020 AT 3:26 PM (Merged)
Tiny
WRENCHTECH
  • MECHANIC
  • 20,758 POSTS
You just need to look at it closer. It could be a hose problem, leaking water pump or bad radiator. Use a pressure tester when examining it.
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Friday, September 11th, 2020 AT 3:26 PM (Merged)
Tiny
SDROBISH
  • MEMBER
  • 1 POST
  • 2002 CHEVROLET BLAZER
  • 6 CYL
  • 4WD
  • AUTOMATIC
  • 104,000 MILES
How to replace thermostat in 2002 Blazer
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Friday, September 11th, 2020 AT 3:26 PM (Merged)
Tiny
RHALL77
  • MECHANIC
  • 3,361 POSTS
Drain the cooling system. Locate the upper radiator hose. Disconnet it. Remove the 2 bolts securing the thermostat housing. Remove thermostat. Install new thermostat, clean housing and reinstall all the rest. Fill cooling system and verify repair. Let me know if you need more help.
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Friday, September 11th, 2020 AT 3:26 PM (Merged)
Tiny
THEDON
  • MEMBER
  • 4 POSTS
  • 2001 CHEVROLET BLAZER
Engine problem
2001 Chevy Blazer Engine Size unknown Two Wheel Drive Automatic 110000 miles

I have a 2001 Blazer with a 4.3 L engine and was wondering where the thermostat is located. I read somewhere that the 4.2 is located by the altinator and you have to take the altinator out. Is that true with the 4.3 L also, Thanks, Don
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Friday, September 11th, 2020 AT 3:26 PM (Merged)
Tiny
BLACKOP555
  • MECHANIC
  • 10,371 POSTS
Im am almost positive it is located where the upper radiator hose hooks to the engine.

What it hooks too is the thermostat housing, there should be 2 or 3 bolts holding it on, unbolt that and you should see the thermostat.
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Friday, September 11th, 2020 AT 3:26 PM (Merged)
Tiny
JMFIGARD07
  • MEMBER
  • 1 POST
  • 2000 CHEVROLET BLAZER
Engine Cooling problem
2000 Chevy Blazer Four Wheel Drive Automatic

My blazer stoopped throwing warm air the other day and blew antifreeze. We looked and looked and chould not find any leaks. It usually runs just under 210 and when ti got hot it went up to about 230. I pulled over and looked under the hood. Definately no antifreeze left and I knew this much because of the no heat issue. We added antifreeze and looked for leaks. Nothing. We called my husbands father who is a retired mechanic and he said it sounded like the thermostat got stuck. So now my husband needs instructions on the removal and replacement of the thermostat. I had the entire cooling system replaced in 2006 so Im hoping it is just the thermostat. Hoping you can help. I do need the blazer to go back and forth to work about 20 minutes each way the next couple of days and I am keeping a close eye on the temp. Just crossing my fingers it doesn't happen again before it can get fixed.
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Friday, September 11th, 2020 AT 3:27 PM (Merged)
Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
Removal Procedure


https://www.2carpros.com/forum/automotive_pictures/12900_therm1_1.gif



1.Remove the necessary coolant from the radiator. Refer to Draining and Filling Cooling System.
2.Remove the air outlet duct. Refer to Air Cleaner Outlet Duct Replacement.
3.Remove the throttle body bracket. Refer to Throttle Body Assembly Replacement.
4.Remove the thermostat housing mounting bolts.


https://www.2carpros.com/forum/automotive_pictures/12900_therm2_1.gif



5.Remove the thermostat housing from the lower intake manifold and set aside.
6.Remove the gasket or O ring.


https://www.2carpros.com/forum/automotive_pictures/12900_therm3_1.gif



7.Remove the coolant thermostat.
8.Clean all the sealing surfaces of the coolant outlet.
9.Clean the sealing surface on the lower intake manifold.

Installation Procedure


https://www.2carpros.com/forum/automotive_pictures/12900_therm4_1.gif



Important: In order to prevent leakage, thoroughly clean all parts and sealing surfaces.

1.Install the coolant thermostat.


https://www.2carpros.com/forum/automotive_pictures/12900_therm5_1.gif



2.Install a new gasket or O ring.
3.Place the thermostat housing on the lower intake manifold. Ensure the gasket or O ring is in correct position.


https://www.2carpros.com/forum/automotive_pictures/12900_therm6_1.gif



Notice: Refer to Fastener Notice in Service Precautions.

4.Install the thermostat housing mounting bolts.
*Tighten thermostat housing mounting bolts to 19 Nm (14 ft. lbs.) .
5.Install the throttle body bracket. Refer to Throttle Body Assembly Replacement.
6.Fill the cooling system with specified coolant and concentration. Refer to Draining and Filling Cooling System.
7.Install the air outlet duct. Refer to Air Cleaner Outlet Duct Replacement.
8.Inspect all sealing surfaces for leaks after starting the engine. Refer to Cooling System Leak Testing (On-Vehicle) or Cooling System Leak Testing (Off-Vehicle).
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Friday, September 11th, 2020 AT 3:27 PM (Merged)

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