Question about 2004 Chevrolet Blazer

2 Answers

Thermostat? sometimes the temp gauge goes into red then back down. sometimes heat doesnt feel hot.

Posted by on

2 Answers

  • Level 2:

    An expert who has achieved level 2 by getting 100 points

    Hot-Shot:

    An expert who has answered 20 questions.

    Corporal:

    An expert that has over 10 points.

    Mayor:

    An expert whose answer got voted for 2 times.

  • Expert
  • 33 Answers

It actually sounds to me like you're low on coolant. My Jeep leaks coolant and whenever it gets low the temp gauge will go real high and then drop, and the heater doesn't work well. This is because the cooling system of your car is supposed to be a closed system, full of coolant and no air. When coolant leaks out, the space it used to occupy is now occupied by air, which does not transfer heat well. When 'air' is passing through your cooling system, no heat can be transferred from your engine to the heater and radiator, resulting in a hot engine and no heat at the heater. Then when a pocket of water passes through the system, the temperature gauge quickly falls as the water absorbs the heat from the engine. The hot water that cools the engine is where the heater gets it's heat from as well, so when water passes through the heater core, the heater works, but when it's filled with air, it doesn't.

Hot water runs through the heater core regardless of whether or not your thermostat is open or closed. That's why your heater works in the winter even before the engine is at normal operating temperature. The fact that the heater stops working is a good sign that the thermostat is probably not the culprit.

As for the water pump. If the water pump was bad, your temp gauge would go into the red and stay there. Water pumps generally don't work intermittently. Either it's good and ot works, or it's bad and it doesn't.

However, if you are in fact low on water, as I suspect, it means you probably have a leak somewhere. The leak could be in the water pump housing gasket, so depending on where you take it for repairs, they may try to sell you a new water pump anyhow. So just beware of that.

Posted on Feb 12, 2009

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    All-Star:

    An expert that got 10 achievements.

    MVP:

    An expert that got 5 achievements.

    Genius:

    An expert who has answered 1,000 questions.

  • Master
  • 2,920 Answers

It could be the thermostat or the water pump . id change the thermostat first and if that doesent fix it then you are looking at putting a water pump on

Posted on Feb 12, 2009

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

2 Answers

I have a 02 Grand caravan that has new radiator, termostat, one new fan. the temp gauge goes up to max hot the drops right back down in seconds. what could be the problem?


it could be you have an air lock in the cooling system
remove the rad cap from the rad, start the engine and let it run until the coolant drops (add to fill it back up) or until the coolant boils out of the rad spout.

maybe pull the heat sensor. -replace it OR clean it off, reinstall it.

Mar 12, 2015 | 2002 Dodge Grand Caravan

1 Answer

Why is temp gauge fluctuating?


My first guess -- need new thermostat on engine.
Second guess -- wiring problem from heat sensor to instrument panel.
third quess - heat sensor beginning to fail (replacement needed)

Mar 12, 2015 | Cars & Trucks

1 Answer

Temperature gauge cold then back to normal


You have to make sure the thermostat is working properly and is the correct one. Idle the vehicle for about 20 minutes and then feel the upper radiator hose. It should be hot to the touch. Drive the vehicle and when the temp gauge falls to 'cold' stop and feel it again. If it is much cooler to the touch than before the thermostat is defective or wrong.

Mar 23, 2014 | 2000 Ford Ranger SuperCab

1 Answer

1996 jeep cherokee temp gauge reads hot 10 mins. after start-up


If you have a viscous fan hub then have it replaced as it is not drawing air through the radiator at idle or slow speed (crawling traffic). Check that are no air locks in the system as they will cause heating problems.

Jan 09, 2014 | Cars & Trucks

1 Answer

Cause no heat temp gauge red lined in


sounds like the thermostat is stuck shut..unless the head gasket is blown somewhere.. it will pump the antifreeze level down to form an air pocket.. this will cause overheating constantly check each cylinder for even compression..the lowest reading will most likely be the blown cylinder..

Dec 15, 2013 | BMW Cars & Trucks

2 Answers

Heat not blowing hot air and car temp gauge goes high


the way to check the thermostat is with the motor hot feel the upper radiator hose to see if can squeeze it. you should be able to squeeze it. the water pumps is big problem to

Jan 26, 2013 | Chrysler Cars & Trucks

1 Answer

2001 grand caravan engine doesn't heat up. doesnt seem like any circulation don't feel anything in top radiator hose.temp gauge doesnt above 1/4 also fluid in radiator is just warm


While engine running, does the air feel warm to hot blowing through the radiator, if it does water is circulading, if it feels cold, replace thermostat.

Dec 04, 2010 | 2001 Dodge Caravan

2 Answers

Over heating on gauge, both fans on rad.


I would say check your coolant level, and change your thermostat. And see if it is high fans or low fans when they come on. There is a fan control relay down on the drivers side frame right under the air box that goes bad too if your fans arent working quite right to check if all else.

Jul 25, 2010 | 1999 Dodge Caravan

1 Answer

Temp gauge goes up and down


first i would purchase a new radiator cap 15 lbs 16 lb capacity cost about $7..then you must let car cool completely...now check radiator coolant level.. top off if it needs it. Now install new cap..let car warm up normally and after it get to normal temp range or higher put hand on upper radiator hose..it should feel hot and when you squeeze it you should feel a slight back pressure..this will mean that the thermostat and water pump are working correctly. if not either the thermostat you purchased is defective or your pump may not be working properly.
when you use just water in an engine the boiling point becomes 212 when you add the correct amount of antifreeze, depending on where you live, the boiling point will go up to 240 degrees. Make sure you put in the correct amount of mix.50/50 will usually work well. sometimes when a gauge does max out like that it could just be trapped air. if after you checked all this out and no air is trapped in the system, i would think that you may have a bad temp sensor. let me know if this helped thanks.

Apr 28, 2010 | 1999 Ford Expedition

Not finding what you are looking for?
2004 Chevrolet Blazer Logo

399 people viewed this question

Ask a Question

Usually answered in minutes!

Top Chevrolet Experts

yadayada
yadayada

Level 3 Expert

60667 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

21936 Answers

Jeff Turcotte
Jeff Turcotte

Level 3 Expert

6811 Answers

Are you a Chevrolet Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...