Happy Gilmore

Hey guys, I've been having a ton of issues with my 4runner lately and I don't know what to do so I felt like reaching out here would be the best thing.

I have very minimal car experience, so apologies in advance if I sound like an idiot.

1986 Toyota 4runner automatic transmission with 22RE

So recently I replaced the radiator but never fully burped the system (I know, how stupid). I've been using distilled water because I live by the beach in California and it doesn't get freezing cold here.
After replacing the radiator and thermostat, my friend noticed some milky oil in the oil cap, so he decided to put K-Seal into the radiator to hopefully plug a leak if there was coolant going into the oil and/or a blown head gasket. Probably not the best idea, but I listened to him anyways. Note, only the cap had milkyness in it, not the actual oil itself or dipstick.

Ever since I replaced the radiator, whenever I'd go for a drive for a while and stop, the reservoir would be filled, and it would never suck it back into the radiator. So before I'd start it up again, I'd wait for it to cool down, and then I'd pour the contents of the reservoir back into the radiator. I'd notice there would be a bit of a loss of water, so I'd top it off with a little more distilled water.

I've been doing this for a couple weeks now, and today I decided to burp the whole system before going for a drive. Filled up the radiator, burped it while cold, turned the truck on with the heater full blast while idling, and continued to squeeze the hoses to get all the bubbles out. After 45 minutes of burping with the car on and idling, bubbles were still coming out, but a lot less. It got to a point where I felt like the bubbles were never going to stop coming, so I threw the radiator cap back on and took it for a drive.

After about a 5 min drive, I pulled into a parking lot and my radiator was spewing out from the front right side, making a whistling noise. Coolant (distilled water) was dripping everywhere. So I took it back home and it's been sitting since.

I just got an oil change 3 weeks ago, and the dipstick has been reading higher than full as of lately because I figure coolant has been getting into the oil. So with that being said,

What should I do next/ how do I diagnose what the problem is/ how do I know if I have a blown head gasket?

• Loss of coolant (dipstick has been reading higher than full)
• Milky oil only in cap, not in oil itself or dipstick
• Coolant in reservoir will not go back into radiator
• Thermostat replaced 2-3 weeks ago

Anything helps. Thank you!

Jimkola

First, you need coolant. And not all coolants are the same. Some are designed for cast iron(green coolant typically) While the pink/red coolants are usually found in Asian vehicles due to their abundant aluminum components. So get pink/red. Distilled water is perfect to dilute a concentrated coolant, though many are sold premixed these days.
Second, If you're stuck on a dirt road far from home than those cooling system sealants have their uses. It'll hopefully seal a leak to let you get home and get it repaired. Less-than-honorable people will sometimes use the sealant to hide an issue to sell the vehicle to some unsuspecting buyer.

But at this point you have a bigger issue. I'd recommend block testing the vehicle using a chemical test. It's very simple to do and will confirm if exhaust gas is entering the cooling system, which would indicate a potential headgasket failure. Everything you've written point that way.
Odds are, the head is coming off. How extensive a repair to fix the issue will be determined once the head is off. It's also be a good time to consider other parts to be replaced, like the timing chain, waterpump, etc. A good shop will make those types of recommendations, but it just drives the bill even higher.

You're in a forum where most of us have encountered this concern and decided to repair. Either by ourselves(I'm guessing most) or sending to a shop. There will be many choices regarding how to fix, and quality of parts. It just really comes down to how much you want to invest. Some people decide they really aren't that attached to the vehicle and part ways.
After the block test is done I'd recommend draining the coolant and pulling the sparkplugs. Turn the engine over a few times to blow any water out, then shoot some ATF into each sparkplug hole and reinsert the plugs. The ATF will help prevent rust. Then drain oil to get all the water out. Throw 4-5 qts of cheap oil back in, just to protect everything until it taken apart. Corrosion from water can take a toll quickly, especially on the cylinder walls.
Edit:
Ah man, I forgot to commend you on all the things you noticed, and you thought to include in your post. It makes it so much easier to help in a constructive way. good on you.

Two days ago I was doing yardwork and a lady I've never met walked up and asked if I had seen her dog. "What does it look like?" I asked.
"A regular mutt", was her answer. I kid you not.
I dropped my head.
Details matter

2ToyGuy

That may be a separate problem, all by itself.

There are three hoses on/in the recovery tank. One comes from the radiator, and connects to the tube inside the tank, which goes down to near the bottom of the tank. The third one is a short hose, with a 90° bend in it, which goes from the vent hole in the cap, directing any air, and/or excess water overboard.

If the hoses aren't on the correct tube on the cap, it can cause this problem. Like if the hose from the rad is on the vent hoses nipple, it can't draw water back into the radiator as it cools. It's important to have the hoses on the right nipples, and that they are clamped down snugly. I use small zipties to clamp them down, as they don't rust inside the tank. Just a thought, you might think about, in addition to what Jimkola mentioned. Small matter compared to a cracked head or blown head gasket, but still significant.

Good fortune in this situation!
​​​​​​​Pat☺