[fdbyrne]

I just bought a 2004 4runner SR5 4.0 4x4. I actually wanted a 3rd generation but the price was right on this one. I'll preface my question by admitting that I am the automotive version of a hypochondriac. My mind always jumps to the worst-case scenario.

The truck only has 120k miles on it. The carfax report shows that both previous owners had it regularly serviced at dealerships.

My concern, at the moment, is the brief gurgling sound that I hear for a few seconds immediately after I start it up. It comes from right behind the dashboard and I'm pretty sure it's the heater core. People keep telling me that it's not a problem but these aren't Toyota people so I thought I would ask you guys.

Per the dealership where I got it, the radiator had a leak and they replaced it. I noticed the new radiator before they pointed it out, actually. I'm thinking that they just didn't get all of the air out of the line when they replaced it. My concern is that I just read a post where the same sound was being described as a symptom of a blown head gasket.

With relatively low miles, a good service history, no smoke in the exhaust, and no loss of coolant I'm not thinking that it's a head gasket issue. Is my logic sound? How could I be sure? Compression test?

[Ask10]

Last time I had that issue (albeit with a 3rd gen), it was low on coolant. My head gasket is actually likely leaking, but it has almost 300,000 on it so I just keep topping it off and it keeps running.

[DC runner]

Agreed. You are hearing coolant being moved through your cab lines that move coolant to your heater core and back to the engine. It means more than likely you have either a pocket of air, or are low.

Check the level, if full, burp it.

[fdbyrne]

Thanks for the reassurance. The overflow reservoir has fresh coolant right up to the normal level.

I've seen others suggest burping the system but nobody really explained how to go about that. How would I go about doing that?

[fishtizzy]

My truck is currently doing same thing, only my coolant level is low (still diagnosing the root cause). I'd like to top it off and give it a good burp, so I'd also be curious what the best approach is as well.

[cmoore50]

1. Raise/elevate the front of the vehicle by jack, jack stands, or drive just the front of the vehicle onto a curb

2. Remove the radiator cap

3. Run the truck for 10 or 15 minutes at operating temperature

That should get most if not all of the air out of the system. Obviously, make sure that you don't take the radiator cap off when the engine is hot.

[fdbyrne]

Thanks. I'll give it a shot.

[menkupalme]

It means more than likely you have either a pocket of air, or are low.

[sigepbiker]

I've got the same issue and been forgetting to raise the question. Thanks for starting the thread. Hope it's just low fluids.

[Nevek08]

Hello everyone. I know this is an older thread but I wanted to see if I can get some feedback. I'm experiencing the same thing and was curious.. How many of you ended up with head gasket.

[fdbyrne]

Mine was the head gasket.