Gurgling water sound from behind dash - heater core? Replacement fan = related?

[kageryu]

I've recently noticed a gurgling water sound from inside the dash when accelerating away from stoplights. Suspecting the heater core, some googling supports that theory.

Has anyone heard this in their car? Wondering if it's just something inherent to the vehicle line, or if I'm looking at a real problem. I did just have my cooling fan die a couple of months back, but I didn't drive on the engine once it was reading hot for more than a minute or so.

Does replacing the cooling fan involve any sort of monkeying with the radiator, coolant lines, etc?

(Sigh. No reason for my car to be jealous of the wife's new-old 2010 Ecoboost Flex.. it's still a year newer!!)

 

[Phoenix]

I got this in my 2010 Fusion 4cyl.

Went to dealer , they said the problem was noticed and engineers were into it. I think its a big load of BS.

I got 30,000 miles on it now and I dont hear it anymore , my wife does though but its always when im not there , go figure.

 

[LJRuddy]

Dad's 2001 Blazer does this a lot too. Never had an issue from it and the heater blows fire so he doesn't worry about it.

 

[kageryu]

Hah. Ok. Somewhat reassuring. I had seen stuff on other sites (about totally different cars) about how that meant air in the system, which meant potentially blown headgaskets... an idea which I find HIGHLY undesirable :-/

 

[PopolZ]

My subscription on motorcraft service ran out so I can't check the service manual but there has to be an air bleeder somewhere in the cooling system (I hope). Basically you get your car warmed up to get the thermostat to open, heater on, open the bleeder until no more bubbling. You may want to get the front end on ramps as it will force the air up.

Someone with an access to the service manual should be able to confirm this or tell me i'm an idiot LOL

 

[D5mckelvey]

I have this sound now too, accompanied by a strange coolant smell in the cabin on a very rare occasion.

Did you ever figure out what the deal was with yours?

 

[shomeda$]

I am having this issue.. i sounds like whurling water and when I start the car, turn the heat on 90 in the morning, it blows cold air, I hit the gas FIRE AIR!!!! Need some help!!!

 

[markathome]

Mine has always made the gurgling noise as coolant flows through the heater core, etc. Once it has warmed up, the noise stops.

 

[91hybrid]

I am having this issue.. i sounds like whurling water and when I start the car, turn the heat on 90 in the morning, it blows cold air, I hit the gas FIRE AIR!!!! Need some help!!!

I have a similar issue on my 2011. In the mornings I hear a water movement sound and when it was super cold here a few weeks back (0-6 deg. F) I was waiting for my daughter to get back from a basketball game and fully warmed up at idle (600ish) I started loosing my heat. If I reved and held the rpm's over 1200 or so the heat almost instantly came back. It wouldn't always do this but it hasn't been that cold in a while either. I think a air pocket sounds probable, the question is why? I don't have an antifreeze smelling exhaust, recent plug change there was no antifreeze deposits and I'm not seeing water in the oil either. I may test the cooling system for leaks.

John

 

[Zylfrax791]

I think its basically just kind of a design flaw that we're hearing the coolant circulate through the heater core. Also, in the winter my 2010 SHO will warm up pretty quick but then once in awhile after about 10 minutes the vents blow cool air for about 5 minutes and then back to warm air soon thereafter. Obviously its just the thermostat kicking open and flooding the heater core with the remaining cold coolant. My solution is just turn the stereo up.

 

[markathome]

Got an answer for everyone on this issue....bad heater core!
I noticed that while sitting at idle, the air would get cooler, then cold...been like this for a while. I never mentioned it to the dealer as it wasn't a big deal. Now that the temps are hovering around zero, for the first time since I've owned this car, the cold air is much more apparent.
I took the car to the dealer and left it idling. Once I got the service adviser back outside, it was blowing cool air. As soon as we got the RPM's over 1k, the hot air returned.
They ran a few test, checked for air, and determined it was a bad heater core. Thankfully I purchased the Ford extended warranty and this item is covered with a $50 deductible and rental. I'm at 39k miles. He said the labor alone would run near $700 and take two days. Apparently, according to the dealer, the heater core has a bypass valve that allows coolant to bypass the heater core if there is any blockage or resistance. At idle, there is enough resistance to prevent coolant from flowing thru the core.
Parts ordered, hopefully to be fixed one day next week.
This is the first I've heard of the heater cores being bad.

 

[Crash712us]

Sounds a bit weird to me, I've worked cars for years. And have encounter bad heater cores, that where plugged and they always blow cold air or very little when rpms are raised. Bad water pump often behave this way when impeller is corroded away.
No I certainly do not believe anyone heater core is clogged or has a bad water pump yet, as I've heard many complaints about this on cars that where brand new.

Its my opinion that there is air trapped in the system, many new cars the heater core is the highest point in the cooling system. And this why this cars must have there cooling system vacuumed down to properly to fill them. Personally I would be leaning toward having them replace bypass valve.
Not sure what purpose the bypass valve ultimately serves? And why it would be need to bypass the coolant flow in the event the heater core becomes blocked. As in most cars that circuit isn't vital to the engine cooling, another word if heat core becomes block that it would starve the engine of coolant.
Just my 2 cents.

 

[Crash712us]

I think its basically just kind of a design flaw that we're hearing the coolant circulate through the heater core. Also, in the winter my 2010 SHO will warm up pretty quick but then once in awhile after about 10 minutes the vents blow cool air for about 5 minutes and then back to warm air soon thereafter. Obviously its just the thermostat kicking open and flooding the heater core with the remaining cold coolant. My solution is just turn the stereo up.

This is perfect example of low coolant or air trapped in the system.

 

[markathome]

Thanks Crash712us, I'll let everyone know once the work is performed.
Apparently some of the symptoms of a bad heater core are gurgling and no heat at idle. They assured me there was no air in the system.

 

[Crash712us]

For the sake of argument, I would how much trouble it would be to replace one the heater core lines with a clear neoprene line. Perhaps someone with their warranty out can try before they spend big bucks on having hear core replaced.

 

[brucelinc]

I had the issue of no heat at idle a couple of winters ago. If I would raise the RPM to a bit over 1000, the heat would come back. I added some coolant and actually went a bit above the "full" line. That completely solved the problem and I have never had the issue again.

 

[SHOtime2511]

Air in the cooling system.

 

[integrity6987]

Please - Let us know if this fixes it at idle.

Got an answer for everyone on this issue....bad heater core!
I noticed that while sitting at idle, the air would get cooler, then cold...been like this for a while. I never mentioned it to the dealer as it wasn't a big deal. Now that the temps are hovering around zero, for the first time since I've owned this car, the cold air is much more apparent.
I took the car to the dealer and left it idling. Once I got the service adviser back outside, it was blowing cool air. As soon as we got the RPM's over 1k, the hot air returned.
They ran a few test, checked for air, and determined it was a bad heater core. Thankfully I purchased the Ford extended warranty and this item is covered with a $50 deductible and rental. I'm at 39k miles. He said the labor alone would run near $700 and take two days. Apparently, according to the dealer, the heater core has a bypass valve that allows coolant to bypass the heater core if there is any blockage or resistance. At idle, there is enough resistance to prevent coolant from flowing thru the core.
Parts ordered, hopefully to be fixed one day next week.
This is the first I've heard of the heater cores being bad.

If needed maybe more of us can hit up the warranty - I bought ford warranty on my CPO and what to get something out of it, but don't want to have the car torn into if this does not fix it.

The fit/finish of may car is very good - now squeaks or rattles AT ALL at almost 80K

 

[markathome]

Just an update....
You guys scared me off from having the dealer take the dash apart to replace the heater core.
So, I tried the earlier suggestion by brucelink, of putting extra coolant in the reservoir. I went just a little over the full line. Interestingly enough, it took almost 1/2 gallon to bring it to this level.
After a day or two, the gurgling stopped and the heater is at full heat while idling.
I'll get around to telling the dealer about the fix next time I have it serviced.

 

[brucelinc]

Thanks for the update, Mark. I wouldn't want anyone tearing into the dash if it wasn't absolutely necessary!