Coolant bubbling

The other day heard my coolant bubbling in the overflow after shutting off my truck, thought maybe it was low and there was air it it so i filled it up. Just yesterday i noticed my overflow was completely empty so i got some coolant and filled the radiator and overflow and bled some air out of the radiator. Took it on a drive, got back and heard it again bubbling again, the overflow was completely full and what looked like exhaust gas or steam was coming from the radiator cap. Im really hoping i dont have to do a head gasket. My heat has also been cutting on and off recently could that be related or two separate issues? What can i do to test if i blew a head gasket? (Oil is good)

 

Definitely related. Make sure you are keeping the radiator topped off. You can do a coolant pressure test to see if there is coolant leaking down into the cylinders

 

i will rent out a pressure tester and check it as i dont own one, i have a bottle of coolant in my truck now. Also recently noticed if you drive the truck for a while or at higher rpms it will start to smell like somethings burning and then smoke will start to come out of the vents but under the hood there is no smoke. Is this a related issue or something different causing it?

 

Unfortunately, the symptoms point to a blown head gasket. There are several test kits to help confirm this, keyword: head gasket leak test kit.

 

Wow this is what happened to mine thanks on the information I did have my heater going on and off and we just thought heater going bad when I contacted Toyota dealership they said yes there was a recall on the heater but because it was over the statutory time I had to pay for it, so I got it fixed before this I had a empty radiator ever I had it service and now few months later later when I had oil change was told head gasket going bad because of the milky substance in it. I did a post on it trying to get some helpful information

 

Look at the inside of your oil filler cap. If there's white goo, you have coolant in the oil.

Everything you've described is consistent with a bad head gasket or bad head.

I'm sorry.

 

Good advice, but even if the oil is clean, this might still point to a blown head gasket. If the oil is milky it's even worse, and you should immediately stop driving the truck.

Look under the truck for signs of a coolant leak... might be a hose or the heater core. Esp. with 'smoke' coming from the vents, that points to heater core.

Here are three scenarios:
1. You are leaking coolant from a hose or radiator (or heater core), which is allowing air into the system, and will cause overheating
2. Your cooling system is clogged or otherwise underperforming, leading to localized overheating and boiling which is overflowing the tank, then drawing air as it cools. This is especially bad, because overheating is already happening.
3. You have a head gasket leak, which is letting exhaust into the system, displacing coolant, and will soon cause overheating

In any case, if your heater is working only intermittently, then you are low on coolant and at risk of overheating the engine. You should fix this ASAP.

If you see a continuous stream of bubbles at the tank, with the engine warm and idling, then you have a head gasket problem. By continuous, I mean you will see a bubble come up every now and then, no matter how long you wait. Or a rush of bubbles when you rev the engine, no matter how many times you rev the engine. You don't need to do any additional testing in this case, such as pressure testing or exhaust gas testing. You are watching exhaust gasses bubble out of the tank.

Here is a resource for the HG repair. You can find other resources linked there, and elsewhere by searching the forum.

 

I am fairly certain its the head gasket, constant steady stream of bubbles while running, and can sometimes smell coolant in the exhaust. Ive was driving it for a while before i ever Noticed and still am, and I've had no problems with overheating yet. Theres some yellowish sludge on the oil cap but i believe its just from condensation, as i check the oil before, while, and after driving and its always clean. Do you know what would be causing the smoke with burning smell from the vents? Maybe exhaust gas trapped in the heater core causing it to overheat? It doesn't seem to matter if the heat is on or not or if the fans are on. Id like to stop it from doing that if possible until i get a chance to fix the gasket.

 

I'm honestly not sure, Toyota heater cores seem to be long lived, which is a blessing. Check for debris I the hvac intake, like in the fan area. The more common source of actual smoke is going to be debris or fluids burning off the exhaust/cats. I would recommend fixing the coolant issue asap though.

 

thats not necessarily true. if you drive short distance and dont let your oil warm up to full operating temp that happens under the oil cap, often. had it happen on my last 4runner from dog walks driving 2 mins up the road and parking, for 8 years with it lol

 

Get a chemical block tester see if you have combustion gasses in your radiator

 

My 2005 bubbled in the over flow bottle also when my Head Gasket issue happen. But it only did it twice and it was Months apart. But I had a Very Small hole in where the issue was. When the truck is cold make sure your over flow bottle and radiator is full. Take the cap off the over flow bottle. Start the truck and watch for Bubbles, They can be Very Small so you are going to have to watch close and they might be few and far between each bubble unless you have a big issue. If you see bubbles you have a Head Gasket issue. That is the Exhaust Gasses escaping through your Head Gasket issue. That was the First sign I had an issue. Then we did the Chemical Block Tester.