HELP! Strange gurgling sound at lower RPMs. 06' 4.0

Okay whaddup Tabromas... I've been having this issue lately with my trucket o' joy (06' 4.0 DC Prerunner Sport just hit 92,000 miles). It's been making this gurgling type sound coming from the engine area. To compare, It almost sounds like someone blowing into a straw inside a glass of soda or someone swishing around fluid in their mouth like mouthwash or something. I can hear it pretty distinctly inside the cab.

I only notice the sound at low RPMs, like if I first pull away in the morning or from a stop light. It's very noticeable driving around town at lower speeds like going to the local post office.. you know, those speeds. Once I get to higher speeds or higher RPMs in lower gears, the noise is undetectable. This noise doesn't seem to go away whether the truck is warmed up or not, engine temp doesn't seem to matter.
Edit: The sounds is absent during just regular parked idling as well. It's only when moving at low speeds.

On top of this my acceleration seems very slightly less responsive. It seems like I have to give it a bit more gas to get it moving from a stop. It is not delayed, just requires more pressure.

I know I should be doing my 90k service right now, but money is tight at the moment and if I can't tackle all the services at once, hopefully someone can point me in the right direction and I can get my toy taken care of for the time being. Thanks a lot for your time fellas! -Dave

 

Sounds like the air intake rattle??? Mine use to do that until i fixed it with foam around it... Worth checking... Out...

 

Possibly low on anti-freeze ? Check coolant level
You can hear coolant flowing through the heater core when the level gets low causing a gurgling sound like you describe .
Maybe time for a thermostat / water pump / rad cap etc etc

 

I have the same noise on my 2006. Been doing it for a few weeks and trying to find what it is? It almost sounds like an exhaust leak when truck is in low rpms

 

^^^This^^^ I had the same problem last year. The inlet/outlet for the heater core is right in front of you, in the engine bay. That's why you can hear it so clearly. Check the overflow reservoir, it's probably dry or really low.

I topped mine off, when the engine was cold, and also topped off the radiator. Then start the truck, let it warm up with the radiator cap off and let it burp off all the air that is entrained in the cooling system. Problem solved.

 

This sounds good and I will get at it asap. Thanks very much for your input and the guys above! Is it possible this could be it considering that I'd only hear the gurgling sounds while driving at slow speeds though? Just trying to narrow it down a little bit.

 

Yes , you will hear gurgling more at low speeds if the coolant is low .The water pump is turning slow .
Have you checked your fluid level yet ?
Any leaks showing on your driveway ?

 

All fluid levels are where they want to be. No drops of fluid in the driveway. No indicator lights on or anything either. Kinda stumped on this. Maybe the water pumped is just getting weak..

 

Did you take the cap of the radiator (WHEN COLD of course), start it up and let it run and let it get hot? If there is air in the system it will push out the air and the fluid will drop.

Or maybe there's a squirrel doing bong hits in the engine bay.

 

Definite possibility.

 

Mine is doing the same thing, I'll try and burp the system this weekend. Glad I found this thread...

 

Thread revival...

Any updates,guys?
I'm experiencing the same issue.

 

I know this is kind of useless information... but I kind of just ignored the sound since everything seemed fine and it just went away as time went on. I attributed the sound to the cold temperatures in winter here in New England and by the time it was warming up to the 50s-60s, the sound was gone.

Looks like you're in Cali where it's warm all year, so I wish I could be more help. Good luck.

 

So I took a look under the hood at the coolant level as some members suggested and it looks like i'm on the low side. I'm gonna fill it up when I have the chance to and report my findings.

 

I had that same issue. Burped and topped off coolant but came back. While driving, it overheated but the temp gauge never moved and so it was driven a while at high temp and head gasket then needed to be replaced. Careful!

 

Wow. I will be monitoring mine. Thanks for the heads up.

 

So anything else on this? I'm having a strange noise at lower speeds and rpms now as well. Typically around 35-40 mph, usually 4th gear and around 1200-1400 rpms. I'm wondering if anyone has figured this out yet.

 

V6 2006 prerunner 200k
Just discovered this same issue... when going slow i can hear a muffled tapping/ bubbling or gurgle ( really hard to discribe the sound) .... when i put it in park and get out to check it, the sound goes away> I can hear it in the cab pretty well... not really as much in the engine bay.
Has anyone discovered and corrected this issue?

 

Thanks for the reply,
Not running the ac or fan. The sound is somewhat dependent on rpm.... If i step on the gas and accelerate for a short distance the sound gets louder. When i stop and let it idle the sound gets quieter till it disappears.