How to Burp Your Car's Cooling System





Introduction: How to Burp Your Car's Cooling System

About: Hi All! I like to learn, Period. It does not matter what it is. I then try to pass any and all knowledge that I find and learn to all of you. Which is why this site is perfect for doing so!

This instructable will walk you through the simple process of "burping" or getting all of the trapped air out of your cars cooling system. This works for ALL Vehicles

If you have had any parts replaced on your cars cooling system (radiator, waterpump, new hoses, ect) then there is a chance that your cooling system has air trapped in it and this could make your cars cooling system operate poorly, or in worst cases minic the symptoms of a cracked  head.

So BEFORE you spend thousands of dollars at the mechanics having this done, try this and see if your cooling system operates normal (temp stays within normal , does not get hot or overheat).

Step 1: Things You Will Need

AnitFreeze or Dex cool, I used the 50/50 water dexcool mix

Spill free funnel ($20.00 on

Rag to wipe area clean

Time and Patience

Step 2:

Make sure that your overflow tank is at the level of coolant where the line marked "COLD" is, make sure that you car is cold, do not try this with a engine that has been running.

Open your radiator cap, insert the angled peice of the spill free funnel into the correct cap for you car, then the main peice of the funnel on that, Make sure that you have all conections on sung so that there are no leaks.

Step 3:

Now fill the funnel a little past half way, the reason for this is when your cars thermostat opens up the level will rise and drop with the opening and closing of it and with the escaping of the trapped air.


Step 4:

Go to your car, and set the climate controll settings to the hot or heat setting but make sure that the fan/heater is in the OFF posistion.

NOW you can start you car.

Step 5:

This is where the waiting happens, your car has to get up to temp so that the thermostat opens up to cool your engine, one this happens you will see the coolant level drop in the funnel, and a few to a large amount of air bubbles comming up from the coolant, this is the trapped air escaping your cooling system.

Sit back and watch this happen while enjoying a cold one, cuase in order to fully Burp your system the engine has to go through SEVERAL COOLING CYCLES........

I gave it the standard hour of running, if you still see air bubble comming out after that, check your overflow tank and make sure it has coolant in it. If it does not add some so the level is at the HOT line (becase you have now been running your car for awhile now).

The bubbles should stop and when it does turn your car off.

Step 6:

Now you will use the plug that came with the Funnel and plug the hole in the funnel so you can recycle or put the unused collant back in its container, do this with the plug in the funnel , put the funnel in the opening of your coolant container and lift up to remove the plug.

Take the funnels cap off of your radiator and put your cap back on, use the rag to wipe any coolant off of your car.

Now when you drive your car you should see a big differance in how it cools your engine. If you are still getting high temp readings  you might want to check to make sure that your thermostat is working and replace it if needed.



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    5 Questions

    We ran our2004 GMC Sierra following these burping instructions for over 30 minutes. The coolant kept bubbling all over the place and the temp got so hot we had to turn off.

    What is going on?


    here is diagram of where mechaic says is now leaking and had nothing you do with thermostat replacement. Is this true?



    I just got my thermostat replaced at shop. Drove it home, 2 miles, and coolant started leaking real bad. Mechanic said is a hose under manifold that had nothing you do with is repair. Is this true? If they didnt properly get the air out and filled it too high would this cause the hose you break elsewhere?

    I was trying to reply. It wasnt working... i have a failsafe thermostat that was installed about a month ago, water pump new radiator was about 2016 ...

    I would try the burping to see if that works if not you might need to do a pressure test, could be a bad head gasket, cracked head...ect, better to do the cheap fixes first and go from there

    If my car is overheating and the coolant comes out of the reservoir or the radiator if the cap is off, does that mean there is trapped air?

    the coolant level rises when the cars temp goes up, then goes to the overflow res, that is how it normally operates. did you check to see if your water pump is working? when was the last time you replaced your thermostat? since most antifreeze is mixed with water there is bound to be some air in your system. (first check to see if your thermostat is working) I like to use the smallest drill bit I can buy and drill a tiny hole in the thermostat (This hole will let some coolant through when the T-stat is closed, but no where near enough to effect the regular opening and closing like it is supposed to do. the hole allows for the air to escape the engine side and not keep the t-stat closed when it is supposed to be open)


    Hey i just replaced my thermostat on a 2013 jeep grand cherokee. Now my temp is running a bit higher than normal (gauge closer to middle) and I hear a gurgling noise when I start up and press the gas. Will this process help?

    6 replies

    yes, once you open up your system to do work on it for any reason you should burp it.

    Earlier, a reader posted this -

    "Worked great! I didn't even use the funnel. I took cap off reservoir let it run for 30 minutes and eventually it stopped burping. I put the cap back on..worked like a charm. I really thought it was a blown head gasket or bad thermostat. The temp was high and erratic and did overheat once. However after doing this burping procedure its steady and cool."

    I've been thinking about this ! Would the following procedure be a good way to do this ?

    With engine cold, fill radiator if needed. Place cold/hot control on hot. Add coolant to reservoir if needed to half full level. Leave cap off of reservoir. Start engine and let it idle. Add coolant to reservoir if needed. When "bubbles" disappear from reservoir, turn off vehicle. Adjust reservoir coolant level as needed.and replace cap.

    yes , and no, yes because that is basically what the funnel lets you do, but NO, because when the thermostat opens and closes the coolant level rises and lowers, and coolant would spill out of your radiator. so when you use the spill proof funnel it prevents the coolant from spilling out while letting you visually see if there are air bubbles still coming out of your radiator.

    I would check to see if your coolant level is low. make sure your car is cold, then start it up with the radiator cap off and see if the level is low. but you could have trapped air if the levels are good. This certainly will not hurt your system, go for it.

    I just finished the process tonight for about 35 more gurgling noise so that must have been trapped air. Thanks mfrontauto?

    04 Honda Civic, let it run for an hour and the bubbles never stopped, the reservoir is a bit overfilled. The coolant also started to look dirty after about 30 minutes, could be corrosion from inside the engine. Any suggestions to get it to stop bubbling? Elevate the front end? Thanks.

    Worked great! I didn't even use the funnel. I took cap off reservoir let it run for 30 minutes and eventually it stopped burping. I put the cap back on..worked like a charm. I really thought it was a blown head gasket or bad thermostat. The temp was high and erratic and did overheat once. However after doing this burping procedure its steady and cool. Very happy ( 2002 Cadillac Deville DTS )

    1 reply

    glad I could be of help

    the car should not overheat during this process. after you have checked to see if your water pump is good, check the coolant levels, then if all of that is good and it still overheats take it to a mechanic to check the heater core and pressure test to check for head gasket leak, if it still has the factory gaskets in it you might want to check the LOWER Intake Manifold Gaskets out/have replaced

    that could be several issues, a blown head gasket, bad water pump or heater core... check by your water pump to see if you see any coolant leaking out by or around it... if that is the case the pump should have a "weap hole" where this happens, that is to visually show you that your pump is bad... if that is not the case you can have your heater core checked, or have a pressure test done to see if you have a bad head gasket. your car should not overheat while idling

    Kind of curious. All the instructions I read and watch have the car on a flat surface. Seems to me it would make more sense to either have the front of the car on ramps or jack stands... Air rises through water, why not make the radiator cap the highest point? The top of the radiator should at least then be higher than the heater core, right?

    2 replies

    Hi John,

    the radiator cap is the highest point, followed by the engine, then the heater core, which is located behind this vehicles glove box. Most/all vehicles are designed that way, unless it is some sort of custom/kit car

    another consideration is the vehicle itself, in my van the highest point is the heater core, then the radiator cap/ reservoir, then the engine.

    Can i do this method if my radiator does not have a cap only my resevior does

    1 reply

    I do not know as I have never tired to burp a cars cooling system like that

    I have a 2002 Chrysler Concorde. I tried using the bleeder for the coolant air. But I must have did something wrong. Because now all I get out of the bleeder is straight Steam air. I did this for about 5 minutes nothing but steam coming from the bleeder. What do you suggest?

    1 reply

    check to see if you have enough coolant in your radiator when it is cold, the try burping your system Like I have shown here