Water gurgling through heater core?

[Redonthehead]

On my '96 suburban, while revving it slightly from idle, you can hear water flowing through what I assume is the heater core - behind the glove box. Sounds like a waterfall. Wife said its been like that for a year. Tried the obvious of filling the radiator, but it didn't help. Is this common?

[Gooseneck]

From what I've read in this forum it is very common. I have a 94 K1500 that does it too. The fix, so they say is to disconnect the heater core hose at the heater core (the one closest to the engine) About 1" inside the core inlet tube is a rubber washer. "hook" the washer with something and pull it out and just leave it out. Evidently this is an orifice that regulates the water flow but needs to be removed to solve this problem. I have not had time to try this on mine so let me know if it works for you.

[Quinnections]

I've always wondered the same thing on my '99. I'll be interested to see if this fix solves the "problem". It's more annoying than anything.

Tom

[Redonthehead]

Well after posting the question I realized after filling the radiator to the brim (and the puke tank to the fill line) I had not warmed the engine over thermostat temp. So after driving the truck yesterday the gurgling has been eliminated or at least diminished greatly. Perhaps the thermostat had to open to get any air out of the heater core.

On a side note, after a 2 hour drive all the fluid in the overflow tank was gone, although the radiator is still full.

[calskywatcher]

I am not a guy who works on my car, but I would love to know if what I am experiencing is something others have encountred.

I have 1994 C1500 Chevorlet Suburban that in general works great.
At 88,000 miles, my heater core started leaking. I took it to my
local dealer, they replaced it, and thus started the odyssey!

#2 failed after 1000 miles, replaced for free
#3 failed after 1600 miles, replaced for free
#4 failed after 2300 miles, replaced for free
#5 failed after 2600 miles, replaced for free
#6 lasted 15 months and 10,000 miles which was unfortunate
since despite my complaints, they made me pay for it
#7 failed 3600 miles later, replaced for free
#8 failed 2000 miles, replaced for free

I now have a verbal promise from the dealership that heater
cores are free as long as I own the vehicle, but my goodness,
what is going on!? The problem is always internal corrosion
so they have tried grounding straps, both to the engine and
the heater core itself. GMC custmer service became useless
as soon as my vehicle went over 100,000 miles. This is my 2nd
Suburban, and I had anticipated I would always buy a 3rd, but
probably not now. I'd appreciate hearing if anyone else has dealt
with this. Thanks.

[J-Ri]

I assume it has the "wonderful" extended life antifreeze in it? That stuff is terrible, causes the aluminum to corrode if exposed to air. Try replacing the radiator cap and the reservoir cap. Also, don't pop the radiator cap off to check the level, even if your reservoir is the black plastic one you can't see through. You probably have a low coolant light that will come on if it empties.

I'd reccomend you flush the radiator and engine and fill it with the good ol' green stuff

[calskywatcher]

At last, a clue! I'll look into it. Thanks for the quick reply.

Originally Posted by calskywatcher

I am not a guy who works on my car, but I would love to know if what I am experiencing is something others have encountred.

I have 1994 C1500 Chevorlet Suburban that in general works great.
At 88,000 miles, my heater core started leaking. I took it to my
local dealer, they replaced it, and thus started the odyssey!

#2 failed after 1000 miles, replaced for free
#3 failed after 1600 miles, replaced for free
#4 failed after 2300 miles, replaced for free
#5 failed after 2600 miles, replaced for free
#6 lasted 15 months and 10,000 miles which was unfortunate
since despite my complaints, they made me pay for it
#7 failed 3600 miles later, replaced for free
#8 failed 2000 miles, replaced for free

I now have a verbal promise from the dealership that heater
cores are free as long as I own the vehicle, but my goodness,
what is going on!? The problem is always internal corrosion
so they have tried grounding straps, both to the engine and
the heater core itself. GMC custmer service became useless
as soon as my vehicle went over 100,000 miles. This is my 2nd
Suburban, and I had anticipated I would always buy a 3rd, but
probably not now. I'd appreciate hearing if anyone else has dealt
with this. Thanks.

[decoy86]

I have 91 GMC and it did the sam ething last week. I filled teh radiator and turn on the engine and heater. When the level in the radiator felll I filled it up. No more problems. I do have a cronic intake leak and need to fix it asap..