The Unfixable Problem!

zibzer · January 2, 2007

So i posted a while back that I had a gurgle in my dash somewhere (likely the heater core), i want to post my story on this. and maybe SOMEONE can help me out!

first very cold morning of the year:

started truck up and had a bad gurgle sound in dashboard on high rpms. 2000+

drove for a week and no change.

Went to the 1st auto mechanic. Took it for a drive and told me he couldnt fix this problem.

3 days later, went to 2nd mechanic. Said its probably a intake gasket leak. Said it would cost 700 bucks to repair and left it at that. (i have no loss of coolant, and no milky oil)

so i went to a 3rd mechanic and had them pressure test the system. Turned out fine. Mechanic had no idea what the problem was but didnt think it was coolant. And didnt want to check the problem any more.

2 days later i went to a GM Garage and the 4th mechanic said that it might be a head gasket, but he also noted his truck made little gurgles when he first started it up in the morning. I said mine does it all the time and isnt little. He didnt want to listen to it for himself and he left it at that.

now today I brought it to a 5th mechanic at a radiator shop. He said hes almost positive it is the heater core. He took the heater hose off and the problem went away... He wasnt 100 percent sure though because the problem will occasionaly go away and then come back. He put a restrictor in their thinking it would help. Well the restrictor did nothing and him and his partner couldnt figure out the problem. I mentioned head gasket. He said I would have noticed bigger problems than a gurgling if it was that.

so here I am. at my wits end on this problem. HOPING that maybe someone on this forum can shed some light for me. let me post what I have found

Likely gurgling in the heater core area.

never lost coolant.

Started on a bitter cold day.

went away New Years day when it was moderately mild outside.

came back when the temps dropped.

Happens with heater on and off

happens with defrost on and off

i even drove around with the cold air on for a day and it still happened.

The times it goes away:

if i drive a lot on the highway and gun the engine a few times it will go away. Once i get back to city driving it will come back after about 2-5 minutes.

occasionally mild days will make it go away (but this is not always true)

rmreid · January 2, 2007

I wish I could help but I can't but I'm interested to see what the brain trust here replies as to what it might be and how to fix it

ken1mod · January 2, 2007

Licensing means nothing. Competence means everything. The two are unrelated.

Good luck on an interesting problem. A licensed hair cutter scalped me last week.

Ken

asilverblazer · January 2, 2007

Still sounds like the system needs burped.

Try this.

If you tried that exactly, I don't know. But I do know your mechanics need smaked.

Trouttrooper · January 2, 2007

I'll bet it's the heater core. My '99 GMC would gurgle and I pretty much pulled all my hair out trying to figure it out before I traded it in. I was told that the design of the heater core and hose routes made it susceptible to air pockets and that's what the gurgle sound was.

Rolandd · January 3, 2007

Just a dumb question, but could it be the A/C system? If the system is over charged or running on too cold a day, the freon (is R-134a still called "freon?") may not fully evaporate in the evaporator leaving you with a bunch of liquid burbling under the dash. The A/C will run in Defrost mode to help clear the windshield and as best as I can tell in my '05 it will run automatically unless the air is directed to the floor or vents only--past the half way point on the control.

You have not lost any coolant yet and it is unlikely that the heater core will breach even if it has gone bad internally. Next summer you can bypass it and see if that eliminates the noise. In the mean time, disconnect the compressor for a day and see what happens.

The other solution to this problem is to get a better stereo!

ZZ327 · January 3, 2007

Just a dumb question, but could it be the A/C system? If the system is over charged or running on too cold a day, the freon (is R-134a still called "freon?") may not fully evaporate in the evaporator leaving you with a bunch of liquid burbling under the dash. The A/C will run in Defrost mode to help clear the windshield and as best as I can tell in my '05 it will run automatically unless the air is directed to the floor or vents only--past the half way point on the control.

You have not lost any coolant yet and it is unlikely that the heater core will breach even if it has gone bad internally. Next summer you can bypass it and see if that eliminates the noise. In the mean time, disconnect the compressor for a day and see what happens.

The other solution to this problem is to get a better stereo!

<{POST_SNAPBACK}>

you could be right, on some pickups you can hear the freon run back through the evap core , sometimes when running or when it gets turned off ( pressure equalizing) He says it happens all he time though?

zibzer · January 3, 2007

Just a dumb question, but could it be the A/C system? If the system is over charged or running on too cold a day, the freon (is R-134a still called "freon?") may not fully evaporate in the evaporator leaving you with a bunch of liquid burbling under the dash. The A/C will run in Defrost mode to help clear the windshield and as best as I can tell in my '05 it will run automatically unless the air is directed to the floor or vents only--past the half way point on the control.

You have not lost any coolant yet and it is unlikely that the heater core will breach even if it has gone bad internally. Next summer you can bypass it and see if that eliminates the noise. In the mean time, disconnect the compressor for a day and see what happens.

The other solution to this problem is to get a better stereo!

<{POST_SNAPBACK}>

that could be a good point but i ran it for a few days in foot mode only (no defrost) and it still happened even without the compressor going. I checked my freon level and when i pushed in the escape pin (whatever its called) air came out only for nearly 5 seconds before freon started coming out. is that normal? or does that mean im low?

doverarjim · January 3, 2007

I just got to thinking about this one, my truck did the same thing a few years ago for about 3 or 4 months. My fix even if I didn't know it till right now was to change out the Dexcool. I flushed and refilled mine with with new Dexcool at about 95,000 miles and until I read this post did not realize that my problem has been gone for the last 32,000 miles!!

Uncle Monkey · January 3, 2007

Been there done that. I had that problem since the truck was new. However, mine is losing coolant somewhere. Pressure test etc show no leaks but I have to add a cup of antifreeze every few weeks to keep the low coolant light off. The gurgling noise disappeared after I changed the coolant and ran the engine with the rad cap off (heater on full tilt) for about a half hour and kept adding coolant till full. It seemed to get all the air out.

fossil · January 3, 2007

Take it to a highly reputable big name dealership. If they cant figure it out then no one can. Be prepared to spend some big bucks though...but then again you get what you pay for. The one I use is real good but unfortunately also charges $160 per hour.

Wingnut · January 3, 2007

Still sounds like the system needs burped.

Try this.

If you tried that exactly, I don't know. But I do know your mechanics need smaked.

<{POST_SNAPBACK}>

My '92 had this issue. Gurgled like a mofo all the damn time. Sounded like I had a Mr. Coffee behind my glove box. Made quite the java addict out of me.

I replaced the water pump, thermostat, radiator, and all the hoses, and it didn't correct it. I'm just glad I replaced all of that because they were going bad/leaking and not to address this specifically. The procedure in that link fixed it for a while. It came back (although not nearly as bad) after 6 months or so.

CoastyAV8R · January 3, 2007

Take it to a highly reputable big name dealership. If they cant figure it out then no one can. Be prepared to spend some big bucks though...but then again you get what you pay for. The one I use is real good but unfortunately also charges $160 per hour.

<{POST_SNAPBACK}>

You need to keep things in perspective first. The problem is you hear a gurgling sound coming from the dash area, most likely the heater core. You have no water in your oil and you lose no coolant so what are you worried about? I wouldn't throw significant amounts of money at something like this, your truck is mechanically sound. It may be quirky like Chitty Chitty Bang Bang but it will get you where your going without worry.

The gurgling sound has got to be your heater core or possibly your air conditioner and I say this because those are the only things in the truck that you could hear from inside the truck. If you are going to have somebody work on the truck I would get the coolant system reverse flushed/cleaned and serviced up and if that doesn't do it, get your freon system completely serviced. Before I'd do either of those, I would burp following the instructions asilverblazer posted. I'll bet you if the burp don't fix it, one of those 2 will fix your gurgling sound. If that doesn't work, turn up your radio.

citydriver · January 3, 2007

Did any of the mechanics check the radiator cap? Does it maintain proper system pressure, or allow coolant flowback to the radiator as the engine is cooling down? Or check the overflow tube or tank inlet for restrictions or even pinholes?

Too many times the simple things are overlooked, heck I've done it myself

The A/C Refrigerant would usually cause a hissing sound as the system pressure equalizes. Mine even whistles a little, but I haven't heard one gurgle.

dewfpo · January 3, 2007

Did any of the mechanics check the radiator cap? Does it maintain proper system pressure, or allow coolant flowback to the radiator as the engine is cooling down? Or check the overflow tube or tank inlet for restrictions or even pinholes?

Too many times the simple things are overlooked, heck I've done it myself

The A/C Refrigerant would usually cause a hissing sound as the system pressure equalizes. Mine even whistles a little, but I haven't heard one gurgle.

<{POST_SNAPBACK}>

I agree, I'd pressure test or replace the coolant pressure cap before I spent anymore money.

We have a baseboard hot water system in our current house that would gurgle, moan and groan every time the circulation pump came on. The outfit that installed the new boiler came out 5 times, bleed the system each time, and it would go away for a while then come back. Turns out they kept forgetting to put 20 psi static pressure in the system. They thought it should be 0 pressure static with a 20 psi operating pressure. Well with 20 psi static in the system, the noises have dissappeard. So lack of pressure was the cause of the noise.

So, that's a long, boring explanation for why I think you should check your cap.

DEWFPO