Percolating noise during idle & after turn off 2007 Subaru Legacy Limited

[kre1997]

For a few months now, our 2007 Subaru Legacy Limited edition has been making a percolating noise whenever we turn it off.  The noise lasts for about 30-40 seconds and then stops.  I have also noticed it recently when the car is idling.

 

I read on a forum that it could be caused by low oil, so I checked the oil and it was really low.  No oil appeared on the dipstick, so I went to a local repair shop to verify that it was low on it.  It was, and the shop added at least a quart of oil.

 

The percolating problem did not go away.  I did more research, and another post suggested checking the coolant level, since it could be caused by air in the coolant.  The coolant, checked when the engine was completely cold, was below the low mark on the coolant bottle.

 

I took the car to a Subaru dealer, because the dealer had to replace the head gaskets about two years ago.

 

Since my family has a very limited income right now while I am looking for a new job, the dealer suggested doing an oil change and keeping a close watch on the fluid levels.  The dealer said that both oil and coolant gets consumed a little over time, and it is not necessarily a concern that those items were low.

 

Since the oil was changed less than 3,000 miles before at a Subaru dealer, I thought it was unlikely that I would loose so much fluid so soon, but I paid for the oil change anyway.  I suppose it was possible that the fluids were not topped off at the previous oil change(s).

 

Due to our limited income at the moment, I haven't driven the car many places other than job interviews after the oil change.  I did check the oil and coolant levels this morning, which is four days after they were topped off, and the levels seem to be at the full marks.  I put newspapers under my car to make it easier to see leaks, and I have not seen any fluids on the newspapers.

 

The symptoms have not changed, however.  The car still makes the percolating noise at idle and when I turn off the car.

 

If it is air bubbles in the coolant, which could have been caused by the coolant being so low for an unknown period of time, will they work their way out on their own?  One repair shop (not a Subaru dealer) said they could bleed the air out of the system for an hourly fee, of course.

 

I have a Subaru coupon that will check and drain the cooling system, pressure test the system and refill with up to one gallon of Subaru coolant and one bottle of Subaru cooling system conditioner for $80.  Would this determine the cause of my problem (such as a bad radiator cap) as well as get rid of the air bubbles (assuming that air bubbles were the cause)?

 

I am trying to resolve this problem as inexpensively as possible, due to our limited income while searching for a new job.  However, I don't want to neglect something that could lead to a larger problem.  Our Subaru has developed a bunch of expensive problems in the past two years, starting with head gasket replacement about two years ago.  I have spent more than $1,200 in the past few months on repairs, so I really hope someone could advise me about what I should do next.

 

Thanks for reading.

[kre1997]

In case it matters:

 

Car has 96,811 miles on it.

 

Both head gaskets were replaced by a Subaru dealer on 11/8/12.  The dealer convinced me to also replace the timing and other belts at the same time, because it would cost less if done at the same time as the head gasket replacement.

 

I don't believe any other needed repairs are related to the percolating noise.

 

The battery died on 1/16/13.

 

The exhaust mid pipe had to be replaced on 10/7/13.

 

Spark plug wires had to be replaced on 7/14/14, because the check engine light came on.

 

Both sway bar links had to be replaced on 8/13/14.

 

Both ball joints had to be replaced on 9/25/14.

 

Heat shields had to be secured on 10/5/14 due to excessive vibration.

 

 

I doubt that any of the above is relevant to the current issue, but I thought I would mention it in case it could be related to the current problem in some way.

 

Also, I had 90,000 mile service done at a Subaru dealer on 4/2/14, and no problems were reported.

 

 

As previously mentioned, any advice or suggestions would be greatly appreciated.

[kre1997]

Sorry for the multiple posts.  I keep thinking of things that could be relevant.

 

The percolating noise sounds like it is coming from behind the dashboard (both when the car is idling and when it is turned off).

 

When the Subaru dealer did the oil change, they topped off the fluids.  They put on my invoice that they did not find any leaks (for the oil or for the coolant).

 

When I went in for service a few days ago, I asked the Subaru dealer if they should add the Subaru coolant conditioner, since it is basically a stop leak, but they said it was not necessary, since they added less than 1/2 gallon of coolant.

 

The coolant wasn't drained/filled at the 90,000 service visit, because it was done at the same time of the head gasket replacement.  The Subaru coolant conditioner was last added at the time of the head gasket replacement (approximately 24,800 miles ago).  The dealer said the conditioner was needed at that time because of the amount of coolant that had to be added as a result of the head gasket replacement.

[1 Lucky Texan]

don't just rely on the level marked on the overflow bottle. When the engine is cold, also check the level in the radiator - it should be completely full.

 

Also, have the a/c refrigerant checked. You car 'may' be old enough to have some leaking o-rings at the compressor or other a/c system leak.

[nipper]

It is not unusual for a car to use 1qt of oil in 3000 miles. It is a bit more then i would like, i would prefer 1qt every 5000 miles, but it is what it is.

 

On the coolant issue, I am going to tell you how to try to solve it cheaply. Since you are in Texas I am not going to worry too much about antifreeze.

 

1- remove radiator cap

2- start car

3- turn heat on

4- wait for your thermostat to open, there will be a surge of fluid towards the filler neck, if not some overflow.

5- top off (with engine running) with deionized water (usually very cheap in a grocery store).

6- replace cap, shut off car, allow to cool off.

7- Repeat

 

It is possible there is some air trapped in your engine making the noise at the heater core. The air could come in from a bad radiator cap, a loose hose clamp, a weeping hose. 

 

You can use cheap oil but reduce your oil change interval, and learn how to change your own oil. The first time you do it it will cost the same as going to a shop, but after that it is just the cost of the oil and the filter.

[kre1997]

Thanks for the replies.  I really appreciate your effort to help me resolve my problem.

 

I have questions about both responses, so I will ask them individually.  I would welcome replies from anyone.

 

don't just rely on the level marked on the overflow bottle. When the engine is cold, also check the level in the radiator - it should be completely full.

Also, have the a/c refrigerant checked. You car 'may' be old enough to have some leaking o-rings at the compressor or other a/c system leak.

 

Question: When I check the level in the radiator, should it be so full that the liquid touches the radiator cap?  (I didn't check it yet; I'm just trying to determine what is considered to be "full".)

 

Would the A/C refrigerant be a possibility if I hear the sounds even when the A/C is not being used? It is fall now, so I typically am not using the AC at all.  I hear the percolating noise even when I don't use the AC for any of the car trip.

 

 

 

It is not unusual for a car to use 1qt of oil in 3000 miles. It is a bit more then i would like, i would prefer 1qt every 5000 miles, but it is what it is.

 

On the coolant issue, I am going to tell you how to try to solve it cheaply. Since you are in Texas I am not going to worry too much about antifreeze.

 

1- remove radiator cap

2- start car

3- turn heat on

4- wait for your thermostat to open, there will be a surge of fluid towards the filler neck, if not some overflow.

5- top off (with engine running) with deionized water (usually very cheap in a grocery store).

6- replace cap, shut off car, allow to cool off.

7- Repeat

 

It is possible there is some air trapped in your engine making the noise at the heater core. The air could come in from a bad radiator cap, a loose hose clamp, a weeping hose. 

 

You can use cheap oil but reduce your oil change interval, and learn how to change your own oil. The first time you do it it will cost the same as going to a shop, but after that it is just the cost of the oil and the filter.

 

Questions:

 

First, is it safe to use deionized water when I live in a place with extremely cold winters, or should I use genuine Subaru coolant?  I live in Pennsylvania, not Texas, and the temperature, unfortunately, does drop below zero.  The car sits outside in the winter.

 

Other people have suggested doing the above procedure when the car is parked on a hill, as gravity will draw out the air bubbles.  My driveway is extremely steep, so that is a great place to park it.  Would parking it on a driveway help?  Would I be able to bleed air out of the system, as some people suggest, just by parking it on a hill for several hours (with the radiator cap and overflow cap open)?  If this would actually work, wouldn't coolant spill out when I took off the radiator cap (from the steep slope)? (assuming that the coolant was full in the radiator)

 

How do you prevent coolant from going everywhere when performing this procedure (regardless of whether I turn the car on or not)?  Do I need to buy a "no spill" funnel and insert it in the radiator fill opening before I start the car, or should I remove some coolant from the radiator before starting the process?  The owner's manual said to not let coolant spill on other parts of the car to prevent a fire.

 

If the problem could be a bad radiator cap, should I replace the cap before I try the above process?  The cap is about 7 years old, and I doubt the Subaru dealers followed bulletin 09-45-06 about cleaning the cap, valve, and filler neck sealing surface every time they checked the coolant.  (The bulletin just says that contaminants and debris can get embedded in the cap seal and prevent a good seal if all areas are not thoroughly cleaned when the coolant is serviced.)

 

Also, I just wanted to mention that I do not have any wetness on the floor mats, and the windows don't get a film on them.  (Some people said this happens if you have a heater core leak.)

 

The heat does seem to work.  Some heat does come out of the vents, however, even when the heat is not turned on.  I'm not sure if that is related to an air bubble or not.

 

Also, the car does not seem to be overheating.  The temperature gauge never goes higher than the halfway point.  It does not seem to fluctuate.  The needle slowly climbs to the middle as the car warms up, and it then stays there.

 

The noise can be heard sometimes when the car is driving, even when it is not idling.  I just dropped my son off at school, which is less than 2 miles from our house, and it could be heard on the way to the school.  The temperature outside is only about 43 degrees.  If the coolant is boiling from the air bubbles, at some point shouldn't this stop, since the temperatures will tend to get colder and colder each day as we approach winter?

 

Finally, I really need someone to let me know if the $80 procedure (pressure test, drain, fill, etc.) is likely to resolve my problem if it was caused by air bubbles.  I will ask a neighbor to help me with all of your suggestions, but I don't have health insurance right now, so I am worried about possibly getting sprayed with hot coolant.  The service would need to be done anyway at some point.  Doing it early really doesn't matter, because it will be performed again at the 120,000 mile service.  The timing is off because we replaced the head gaskets.

 

If the drain/fill/pressure test won't solve my problem, however, I will wait before spending the money.

 

 

Thanks again for trying to help.

Edited October 20, 2014 by kre1997

[heartless]

Question: When I check the level in the radiator, should it be so full that the liquid touches the radiator cap?  (I didn't check it yet; I'm just trying to determine what is considered to be "full".)

 

The level should be very near to touching the cap - at the point where the filler neck widens out. Once you take the cap off you will see.

 

as far as cleaning the cap, you can take a look when you take the cap off - if it looks like there is a bunch of gunk built up, clean it up.

 

I would go pick up a gallon of premixed antifreeze - no need for adding anything to it - and use that to top off your system, if you need to - cost should be about $7 or so

 

the only way that $80 procedure is going to "fix" the problem (if it is air bubbles in the system, and it sounds like it is) is if the system is refilled and burped properly after the drain. Yes, a pressure test would point out any possible leaks, but in all honesty, I doubt that a leak is your problem. These cars a notorius for being difficult to get all the air out of the cooling system after a drain, but it is possible.

[1 Lucky Texan]

Some systems are so automatic now, you may never know when the a/c compressor is actually on. But, if you never hear the noise under conditions which you can confirm the compressor hasn't been operating, then the a/c system is not involved.

 

There really should be no air space under the radiator cap. If it seems to have torn/cracked seals, just get a new one. Most people insist on one from the dealer but I think Stant makes a good replacement.

 

I have heard a 'gurgling' noise once on our 03 Outback from the area of the gas tank. never had a problem or heard it a second time. ???

 

But yours def. sounds like a coolant problem if the sound is from the front.

[kre1997]

I removed the radiator cap this morning, and the fluid was very close to touching the radiator cap.  I noticed a few things, however, that are worrying me:

 

First, there was a little bit of debris on the cap and along the radiator filler neck.  I was able to use a paper towel to clean the filler neck and I got most of the debris off of the cap where I could reach.  When I put the radiator cap back on, however, it sounded crunchy (for lack of a better word) when I pushed down on it.  It definitely sounds like some dirt, etc. is stuck under the cap seal, which I am guessing would prevent a good seal and cause air to get in the system.  Obviously, I should buy a new cap.

 

Before I do that, however, I wanted to mention something else.  When I used a paper towel to clean off the inside of the radiator fill neck and also the cap, I got dark black smudges on the paper towel.  The coolant does not look black, but I am worried about why there would be anything dark black on the radiator fill neck and coolant cap.  Could this be oil?  If so, why doesn't the coolant look black?

 

I do want to note, however, that, according to our receipt from the Subaru dealer, the coolant was not flushed at the time of the head gasket replacement approximately two years ago.  It looks like they just drained/filled the coolant at that time.  Could the black substance be left over from when the head gaskets were definitely leaking before they were replaced?

 

Is a coolant flush, along with replacing the radiator cap, the next step?  The dealer will hook the car up to a machine and flush it for $140 (unless I find a better Subaru coupon, of course).  Some people say flushes are bad, because the flush chemicals are bad for the seals, etc., but simple drain/fills only get the fluid from the radiator.  If dirty fluid is elsewhere, I assume it will mix with the good fluid and find its way back to the radiator and gunk up a new radiator cap.

 

If there is debris in the cooling system and I simply bought another cap without doing the flush/fill or drain/fill, wouldn't it simply gunk up the new cap and prevent a good seal the next time the cap was removed? 

 

Please advise me on what I should do next.

Edited October 21, 2014 by kre1997

[colemanapp]

Sure sounds like a head gasket leaking, exhaust into the cooling passages. When the car is cold, take off the radiator cap and start it up. See if you have bubbles coming out of coolant. If so, you looking most likely at head gasket. Just did it myself.

[heartless]

the black smudges on the papertowel are more than likely from the rubber seal in the cap - it is a common thing and not really anything to stress over. the "crunchiness" you descripe is worth more concern, so yes, go get a new cap - cheap and easy.

 

a proper drain & fill will get the greater majority of the coolant out and is pretty easy to do yourself and a lot cheaper than $140.

get a large drain pan - I like the round container ones with a pour spout - makes it easier to pour the old stuff back into the empty bottles when you are all done. Cost: around $20-25

get 3 gallons of premixed 50-50 coolant - you wont use all of it - probably around 2.5 gallons - Cost: about $7, maybe $8 per gallon, times 3 = $21-24

 

Place drain pan under the radiator drain (usually on passenger side) remove radiator cap, open the drain valve and wait until it stops.

Then, to make sure you have as much out as possible - loosen the lower radiator hose clamp at the radiator fitting, and pull it off - be prepared with the drain pan under it...

 

this is an excellent time to check the radiator hoses over carefully. If the ends are swollen looking (where the clamps sit) or if they feel mushy, or especially weak in a spot when squeezing them, they should be replaced.

 

To refill, make sure the radiator drain is closed, and lower hose is reconnected. If you can, jack the front of the car up a bit to help with air removal. Air will want to go to the highest point in the system.

Disconnect the upper radiator hose at the radiator and slowly refill the block thru that hose. When you can see the coolant isnt draining into the block anymore, reconnect it to the radiator.

There is a small plug on the passenger side top of the radiator that should be removed to help get air out as you fill. a large philips screwdriver will remove it. begin refilling the radiator slowly, give it time to work down in and let the air out. Once the radiator is full, replace the plug on the passenger side, and close the cap. Lower the car if you have jacked it up. check the level in your overflow bottle, top it off if needed - do not overfill! Start the car and bring it up to operating temp (5-15 minutes depending on air temps)

 

Shut the car off and let it cool completely. Once it has cooled off, open the radiator cap and check the coolant level - top off if needed.

For the next week, maybe 2, keep a close eye on the overflow bottle, the fluid should be kept at the proper level. you may need to add a little as the system purges of any remaining air, dont get freeked out.

 

This method has worked wonderfully for me many times.

 

IF you find that the coolant level in the overflow bottle is disappearing after the first couple of weeks, then you may have a bigger issue that will need further investigation.

[nipper]

We found the problem. You need a new cap. The VERY LAST THING you suspect in a case like this is a head gasket. SHame on scaring someone like that even with haloween coming.

 

Replace the cap top off the fluid like I said and you would be good to go.

 

If you wanted to do a flush at this point, I would be fine with it (use my instructions slightly modified) as it is really easy. But for now since money is so tight, lets just replaxe the cap and see what happens.

[kre1997]

Thanks to everyone who offered suggestions to try to resolve my problem.

 

I won't be able to try your suggestions immediately, since I have other things going on right now that demand my immediate attention.  Since the car is not being used hardly at all, except to go on interviews, I doubt that putting this project off for a little while will do any harm to the car.  The coolant and oil levels are still at their full mark.

 

Whenever I am near a Subaru dealer over the next week or so, I will purchase a replacement coolant cap.  I will also either drain/fill the coolant, or flush/fill the coolant, as suggested above.

 

I did attempt to clean the coolant cap this morning to remove debris from the seal.  I ran it under water in my laundry tub, and a lot of debris came out.  I then tried to clean it with a toothbrush, but I couldn't really get under the seal.  So, I cleaned a bucket and filled it with water.  I immersed the coolant cap in the water and moved it around quickly while it was under water to loosen any debris.  A lot of debris came out in the water, so I  emptied the water, refilled the bucket, and repeated the process.  I did this multiple times until no more debris came out in the water.

 

I WILL post again after I try your suggestions and let everyone know if my problem has been resolved.  I really appreciate your help!

Edited October 22, 2014 by kre1997

[1 Lucky Texan]

I'm wondering if someone threw the Subaru Coolant Conditioner or similar product into your overflow tank? That's not the correct way to add it to the system.

[kre1997]

I'm wondering if someone threw the Subaru Coolant Conditioner or similar product into your overflow tank? That's not the correct way to add it to the system.

 

Out of curiosity, why do you think it was added to the overflow tank?  The gunk was on the coolant cap, not on the overflow bottle cap.  I have never added the Subaru Coolant Conditioner (or a similar product) to the car.  A Subaru dealer has performed all of the factory-recommended service, except for one oil change.  Surely the dealer should know where to put the Subaru Coolant Conditioner.

 

Also, I should note that I wiped the coolant filler neck again with a paper towel today, and there were no black smudges on the paper towel this time.

 

 

 

[1 Lucky Texan]

Out of curiosity, why do you think it was added to the overflow tank?  The gunk was on the coolant cap, not on the overflow bottle cap.  I have never added the Subaru Coolant Conditioner (or a similar product) to the car.  A Subaru dealer has performed all of the factory-recommended service, except for one oil change.  Surely the dealer should know where to put the Subaru Coolant Conditioner.

 

Also, I should note that I wiped the coolant filler neck again with a paper towel today, and there were no black smudges on the paper towel this time.

 

 

 

 

The way the system works is, as the volume increases with temp - the radiator cap allows fluid to move into the o'flow bottle. As the syste cools, fluid is drawn back into the rad. from the bottom of the o'flow bottle, thru that small black tube, into the rad. Instructions for the SCC require you to remove 4ozs fromt the rad. and add the conditioner. A lazy or uninformed person might be tempted to add it to the o'flow bottle on the theory it will get pulled into the system. There's a possibility that high concentration in the small tube and tiny reverse valve in the cap could be compromised. The conditioner uses tiny particles (of Ginger I think???? ? ) as a 'carrier' for the silicate or w'ever chemical that is supposed to help with coolant seepage.

 

You might consider taking the o'flow bottle out for cleaning. many of us also cut the bottom of the small dip tube at a 45* angle to help guarantee proper function. All that is out of an abundance of caution.

[nipper]

I'm wondering if someone threw the Subaru Coolant Conditioner or similar product into your overflow tank? That's not the correct way to add it to the system.

 

If that is the case, remove the tank, rinse it out, fill it with a handfull of pebbles and soem water, shake the hell out of it (it scours the places you cant reach) and rinse then reinstall.

[MR_Loyale]

I have had gurgling sounds on my Loyale and had to "burp" the cooling system. Basically when it is cold, start the engine with the radiator cap off and gently squeeze the hoses that run to and from the radiator and watch for bubbles to "belch" out of radiator (car should be idling). Has always fixed it on my Loyale.  Doesn't require a Subaru dealer, specialized mechanic or expensive person, just some effort. Not sure if this applies to later models though.

Edited October 22, 2014 by MR_Loyale

[keith3267]

I think you are looking for problems where none exist and that is why you are spending so money on your car.  Check your owners manual for the service interval on your coolant, its 11 years in the newest models but yours could be as little as 5 years.  Do replace your radiator cap, even if it isn't bad, and I don't think it is.  When they go bad, you see the temp gauge rise when you go uphill, but considering the damage even a little overheating does, you want to head this off.

 

But that percolating sound almost always comes for heat shields.  As they get older, the bolts holding them get a little rusted.  The heat shields are thin sheet metal so they heat and cool rapidly, and when the heat or cool, the expand or contract.  When they do that they move under the rusted bolt heads, but they don't move smoothly.  The sudden movements under the boltheads makes a metal on metal percolating sound.

 

If you are running the AC, it makes a percolating or boiling sound when the engine is turned off as the pressures on the high and low side equalize.

 

BTW, if you are not experienced in changing coolant, or have a friend who is to help you, you should get this done at the dealer.  You have to drain the block as well as the radiator.  Do not let anyone "flush" the system, that does more damage than good.  You will never drain all the coolant out, but you don't need to.  Ethylene glycol does not get used up.  What gets used up is the corrosion inhibitors.  A little used corrosion inhibitors left behind will not do as much damage as minerals that get introduced by freshwater flushing.  Chemical flush products can do a lot of damage to your system and must be avoided.  Most of these attack rubber and other seals.

 

When you get through draining and refilling the system, you need to know where the bleed screw is and how to bleed the system.  BTW, If you do decide to do this yourself, use either Subaru or Peak brand universal long life coolant.  Peak is the closest to the Subaru brand coolant.

[nipper]

For a few months now, our 2007 Subaru Legacy Limited edition has been making a percolating noise whenever we turn it off.  The noise lasts for about 30-40 seconds and then stops. 

 

Heat shields do not rattle when you the car is shut off.

[1 Lucky Texan]

I'm gonna make a nanny post and mention, DO NOT allow pools, slicks or containers of antifreeze to hang around unattended. It has a sweet taste that pets and toddlers cannot resist - and it can kill them.(15-20 deaths/year in the US) very toxic stuff. Destroys your kidneys with insoluble oxalate crystals. The only treatment is to quickly get you drunk 'almost' to the point of lethality with ethanol injection.

 

So, make sure it's disposed of properly.

Edited October 23, 2014 by 1 Lucky Texan

[heartless]

I'm gonna make a nanny post and mention, DO NOT allow pools, slicks or containers of antifreeze to hang around unattended. It has a sweet taste that pets and toddlers cannot resist - and it can kill them.(15-20 deaths/year in the US) very toxic stuff. Destroys your kidneys with insoluble oxalate crystals. The only treatment is to quickly get you drunk 'almost' to the point of lethality with ethanol injection.

 

So, make sure it's [cleaned up and] disposed of properly.

 

one small addition....otherwise, excellent reminder, Texan!

[kre1997]

I purchased a Subaru radiator cap at a Subaru dealer, and a mechanic just happened to be standing near the parts counter.

 

I asked for his opinion of my problem, and he ended up walking to my car with me and listening to the problem.  He listened to the problem from inside the car with the doors closed and the windows up, and he also listened to the problem after raising the hood of the car.  He had me turn the car off and on a few times so he could hear the noise.  He said that the problem was not related to the cooling system.  He felt some hoses and said he was confident that the car was not overheating.  He didn't have any idea of what could be causing the problem, though.

 

I did buy the $8 radiator cap, however, and I will let everyone know if that somehow solves the problem.  I think it is too soon to know, however, since I am doing very limited driving at this time.

 

I also took my car to get its PA state/emissions inspection done today, and I described the symptoms to the mechanic.  We took a test drive and he listened to the problem when he started the car, during the drive, and after he turned off the car.  The mechanic also does not believe the problem is related to the cooling system in any way.  He said this opinion is based on the fact that the noise sometimes starts as soon as I turn the key in the ignition.  He said the cooling system isn't even activated at that time.  He said the fuel pump is the first thing that is activated.  He said the noise sounds like a valve is opening and closing.  He said it could be one of several valves, and he didn't want to just swap out parts until he found out which one was going bad.

 

So I still don't know what is causing my problem, but two mechanics that listened to the noise don't believe it has anything to do with the cooling system.  Does anyone have any ideas of what I can try to determine the cause of the problem?  If it is the fuel pump valve, for example, I could get stranded somewhere because my car might just not start anymore.

 

I am not looking for a problem, just to find it.  I need to know what is causing the symptom, because some of the jobs that I am interviewing for are located in very remote areas.  I would not want my car to break down in the middle of nowhere late at night.

 

Thanks for any advice or suggestions.

[kre1997]

I noticed something this morning, and I wanted to ask if it was normal.  When I replaced my old radiator cap with the new one that I purchased at the Subaru dealer, I noticed about four very small bubbles around the edges of the coolant fluid when I removed the metal radiator cap.  I popped the few bubbles with a toothpick and replaced the radiator cap (using the new one I purchased).  I then decided to park my car on my steep driveway to see if there were more bubbles.  The car was only on for a few seconds, so I thought it would be safe to remove the metal radiator cap, since the coolant couldn't possibly heat up that quickly.  There was only one bubble when I removed the cap, but it was huge.  Does this mean that I have air in my cooling system and that I need to purge it, or are a few bubbles normal?

 

For now, the car is parked on my driveway on a steep incline with the radiator cap off.  I wanted to check later if more bubbles appeared in the coolant.  My neighbor hasn't had time to help me burp the car yet (assuming you guys think this still needs to be done), so I am doing what I can in the meantime.