Blown head gasket on my 2006 4runner V8? Need advice

Hi all
I recently picked up a 2006 4runner V8 sports edition with 200k miles. 2WD

The car fax was clean. No accidents. Timing belt and water pump replaced at 119k miles, and then again at 180k miles (per car fax report)

The car runs great. Motor is quiet and pulls hard. The issue that I’m having is that I’m hearing the dreaded gurgling/slushing sound in the glove box area. Immediately when I start the car up I can hear it. It’s quite loud, and doesn’t go away even when the car is warmed up. I bought the car 2 days ago, and noticed it faintly but didn’t think it was a big deal. Now that I’m researching the topic more, I’m reading that this is a potential HG failure in the works.

I’ve put about 100 miles on it so far. The car doesn’t over heat. No check engine lights, the coolant reservoir is still full. But I haven’t owned it long enough to know if this is gonna be a big problem.

what are you guys thoughts on this car? Did I buy a lemon? I paid 6k for it here in south texas. It was a pretty good deal. The car is very clean.

 

I should also mention that it makes the same gurgling/slushing sound. It’s almost sounds like an electronic whirring sound when I turn the ignition to the “on” position without fully starting the car too.
It’s more pronounced when I start the car however.

 

The V8 is not known for blowing head gaskets, so I seriously doubt that is your issue. What you are reading is most likely related to the V6 motor, which does have a more common issue with the head gaskets.

Gurgling/slushing sound from the glove box are makes me think a potentially clogged AC drain. The drain can be found by looking at the back of the passenger side wheel well, towards the exhaust. There should be a tube about 3" long hanging out in that area that goes into the firewall. It drains almost directly onto the frame. I'm thinking you possible have trapped water in the HVAC because that drain is clogged. So start by trying to clean that out as well as the sunroof drains, which you can see in each corner with the sunroof open.

 

When you turn the ignition to on there will be a small buzzing sound which should stop after about 10 to 15 seconds, this is the ABS/master cylinder electric booster motor, it will also come on about every 3 depressions of the brake pedal as pressure drops and the motor builds up pressure again.

I would be very surprised if you have a blown head gasket on the V8 because as mentioned it's not a common occurrence, early 4th Gen V6s yes it's a possible occurrence, I don't think I have ever heard of the V8 having a blown head gasket, with the exception of a couple that were severely overheated.

 

Thanks for your reply. This sound is constantly ongoing and does not stop. It’s a gurgling sound coming from glove box. It’s very loud.. I keep reading that it could be air in the heater core system or something? Could that be the issue here? I’m going to try to post a video so you guys can hear it.

 

I checked the drain lines and they are fine. Sound still persists.

 

https://youtube.com/shorts/2MGsFhZTrTE?si=elxQHKjqI4ZzXkMF

Here’s a video where I recorded the sound

 

That sounds electronic to me. Like a bad HVAC servo motor.

 

No other symptoms? White smoke out the exhaust? Coolant in the oil? You could always do a compression test to confirm one way or the other. Frankly, I probably would have done the compression test before buying.

 

slight white smoke at start up. Not sure if it’s anything big…. No signs of coolant in oil. No milky substance around oil cap. But it could be that it’s not that advanced just yet…. Yeah I should have done compression test.. Could I do the radiator combustion gas test? I saw one of those on YouTube. Turns the blue liquid to yellow if your radiator has combustion gas in it or something. Anyone know if that’s a reliable test?

car runs really smooth otherwise. No check engine light or codes either

 

it doesn’t sound like air trapped? Like air bubbles?

 

What you are describing is not even close to what head gasket failure would be

 

Don't waste the time or money. It's not your engine. You are looking in the wrong place for the issue. Like I said, it sounds like a failing HVAC servo motor to me.

 

Don't listen to it from the driver's seat. When it's doing it, listen to it standing in the passenger door with your head down by the floor.

In fact, turn OFF all your HVAC stuff. I bet it stops.

 

I did this exactly all day today. No ac or heater running. It’s still making the sound and it’s super loud. It’s constant and doesn’t stop. Ac on or off doesn’t matter

 

I also think it's a failing HVAC servo, mine does similar even with everything turned off.

If it is coming from the heater core I would think trapped air bubbles that a good proper burping of the coolant system may solved.

I still just have a hard time believing it's a head gasket, but do the coolant test for combustion gases, a compression test and I would also use a bore scope in each cylinder after running it up to operating temperature and then it sitting all night to see if any coolant has leaked into the cylinders on top of any of the pistons, if you find no issues after all of these tests your head gasket are fine.

 

thanks. What are other symptoms of failing hvac servo? The hvac system seems to be working perfectly. Blows ice cold. All settings work fine

 

I just posted something about this for my 2004 v8, but mine is on the drivers side under the steering wheel area. As people mentioned here, and in my post, I need to check hvac actuators for the dual climate zone system. Fortunately mine is intermittent but maybe that just means whatever part is causing my issue is slowly going bad.

 

Usually clicking and buzzing sounds and or occasional not going into or partially into the selected mode.

 

Does it ever get louder?