I have an 05 Ram with 160k kilometers on it, 5.7 Hemi engine.

It started this "thing" awhile ago when it was first started up when cold, and sometimes while driving... Its not a consistent problem, it varies. Basically Im getting a flushing/gurgling noise from the heater core which im guessing is air. My main concern is could this be a head gasket failing? It may not be a big deal at all but id just like to make sure, rather get it before it happens if its something serious.

What ive done:

I put a coolant pressure tester on it, brought it to 15 psi and let it sit for around 7 hours at work, when it was checked it was down to 8 psi. There were no visible signs of external leaking from the rad/cooling system or along the cylinder head/block. The only thing I can think of here is either the tester wasnt sealing properly with the rad (yes stupid me did not coat the o-ring with vaseline before putting it on) or internal leakage into the combustion chamber. Id much rather be the dumba$$ that forgot the vaseline lol.

Checked the oil, Normal coloured, does not have the telltale milky colour to it at all

Started the truck cold with the rad cap off and checked for any bubbles in the cooling system, found none, no exhaust smell from the rad either

Got my buddy to start the truck while I was standing at the back and smelled exhaust, did not see a puff of smoke or smell any antifreeze at all.

The truck has never caused me any problems, had it from 25k kilometers on. It is not losing any antifreeze or overheating at all. No abnormal noises/loss of power. Also, the thermostat was replaced awhile ago (4 months) Never acted up after it was replaced just started this now.

Im just wondering what your opinions are? Possible causes of this? Anybody had this happen to them before

 

have u replaced your thermostat...this happened to mine and it was my thermostat...im gettin bubblin/ gurgglin noise as well, but thats cuz i need to add some anti freeze

 

Yep new stat was put in 10 000km ago or so, antifreeze is at proper level, havnt lost any

 

how did you check for the milky oil if you check on the dip stick it wont show but if you take the oil filler cap off that is where mine was milky when i had a bad head gasket

 

May just have air in the system. Might try bleeding the air from the system. Have you checked the actual level in the radiator and not just the overflow tank?

 

Checked both on the dipstick and in the cap for any milky oil, had some condensation in the cap but I figured that was normal, was not milky, no antifreeze smell or taste to it at all.

Antifreeze level in rad is good along with level in overflow bottle

 

I had this once.
It turned out to be my AC of all things.

I hadn't noticed that my AC condenser fan wasn't running and the AC system was over pressurising due to heat build up.
AC was fine when the truck was moving and no "strange sounds" etc, as cool air was flowing past the AC radiator cooling it.
But soon as I stopped and the engine was idling, I could here all sorts of gurggling and flushing sounds from the engine bay.
If all your coolant side of the engine looks OK, have a look to see if your AC fan on the condenser radiator on the drivers side of the truck is spinning when your AC or de-mist is selected.
It must always be spinning if these modes are selected.
Worth a quick look.
Al.

 

Checked the a/c thing, I dont think thats the problem. I also havnt been using the de-frost so the a/c hasnt been operating at all. It will do it when the truck is first started with no blower or a/c on at all. Its definately coming from the heater core.

 

So no coolant loss, no over heating, no leaks externally or internally that you can see and the only really issue here is gurgling noise from maybe the heater core? The go get a coupler and bypass the heater core and see if it stops. Your arent going to be using it any time soon anyway with these temps outside.....lol

 

Yep thats right, no coolant loss, no overheating at all, truck acts and drives just like it always has. Just the gurgling noise from the heater core. Lol you guys are lucky! It isnt that warm up here yet, Still using the heating most mornings, definately wouldnt mind having nice warm weather come up here though!

I just wondered what would cause this to randomly start, thats really all im concerned about. It never has done it before and then all the sudden it started. Wondering what the hell it could be lol