Sloshing sound behind dash again

I know there are a bunch of posts and I have already started trouble shooting.

1. ran the truck with the rad cap off to burp the system but coolant looks good and full and zero bubbles came out. No coolant leaks anywhere and the color is good.

2. heater core issue - not sure where to start

3. ac drain issue - not sure where to start

4. head gasket issue - it’s an 05 4.0 so I know I’m at risk

no water on the floor and vehicle runs fine. Sloshing goes away after driving awhile. I do drive the vehicle only once a week.

 

How does it start when it's cold, 1st start of the day, or after work...? Does it stumble for a second it 3, then smooth out?

If so, then I got some not so good news...

Sloshing... As in what it would sound like if it were a bucket of water? On the passenger side floor area. Or the sound of water and air running through a pipe? Right in front of you in the dash. More of a gurgling sound... This was and the cold start stumble, were my symptoms for needing a head gasket.

Know any HVAC guys? Ask one for a long wide tyrap. Push that up through the AC drain. If there's any water up there, pushing in 12" or so it'll be coming out

 

A/C drain is under the hood on the passenger side (the small rubber hose sticking thru the firewall), turn the blower on high and put your hand in front of it, there should be air coming out of it, it theres not it's likely plugged.

 

Vehicle starts right up, no stumbling, runs normal.

The sloshing doesn’t sound like a ton of water and happens a few times especially on some hard accelerations. Then goes away. I need to do more research on the heater core and ac

 

Too get the heater core out,the entire dash has to be pulled apart a major job,so hopefully that's not the problem.Head gasket job $$$$.

 

Can it be flushed? Think I saw some links and vids.

 

The v6 has connections best the fire wall on the drivers side up high.

On the passenger side, much lower, you'll see something sticking out of the firewall maybe an inch. That should be the drain.

 

Update on this

I burped the system by basically running it with the rad cap off - 0 air bubbles and squeezed the top hose

checked the ac drain line and blew some compressed air and does not appear clogged or anything. No wet floor mats etc

I am at a loss on what to do next.....truck fines fine with no, smoke or cel but still that darn sloshing sound

should I do a full coolant flush?

thanks

 

Fill the tank and remove the half finished soda bottle from under the seat.

 

Gas tank? Nope it’s full and nothing under the seats

 

All the good suggestions were taken.

 

Have you looked under the cowl below the wipers? That’s where ventilation air comes from. It’s a big enough space to fit a half finished soda bottle.

 

Do a Blackstone oil analysis on next oil change?

 

Where exactly, do you localize it when you hear it? In front of you.... Up high, down low, passenger side?

Got a HVAC friend? Ask him for a 3' tyrap. It's wide enough and stiff enough to push through the drain on the passenger side.

I heard water sloshing on the passenger passenger side. The tyrap fixed that.

I heard what sounded like water running through a pipe with air in it. Pretty much right in front of me while driving. If you have forced hot water heating, you've probably heard that sound. That was fixed by swapping the motor.

 

By motor you mean engine? Lol

 

Sadly that's what I meant.

 

Does the heat work in the truck if you turn it on full hot?

 

heat works fine

 

I'm not sure when I started noticing it, might have been happening all along, but over the last year or so I've noticed that when I start my truck too. I can hear water/liquid moving. Almost like it's coming from behind the dash, perhaps the header core is filling up or something. Sound goes away after a min or two. No leaks inside the truck, coolant levels are fine, no bubbles in the coolant, truck runs fine.

 

I did a coolant flush and it still does it....