Brown goo in radiator

'95 Tacoma V6, roughly 200K miles.

After replacing the radiator recently, I've been hearing bubbles and steam coming from the heater core behind the dashboard when I'm accelerating. And there's a bunch of brown gunk in the coolant. There was some brown gunk in the old radiator, but I assumed it was because the radiator was old and gunked up. But maybe not, maybe there was a separate issue apart from the radiator being old and leaky.

What's likely going on here? Please tell me I don't have a manifold gasket leak. And if I do, please tell me that I can do it myself without taking the engine out, and that I can safely drive the car until the summer before I get to it...?

 

Brown Gunk? I'm sorry man that's almost certainly some kind of oil in the coolant. Can you take a picture?

 

Did you do a full coolant flush?

 

Sounds like a typical head gasket leak to me. But you can make sure it is bled properly first by parking with the nose uphill and letting it warm up fully with the rad cap off, then put it back on once it has reached operating temp.

 

I'll see about bleeding it properly, but that wouldn't create the brown gunk, would it? There's just a bunch of brown gook right around where the radiator cap is. It's sort of solid-like, it doesn't look like how I imagine oil in the coolant would look, which I've heard described as looking like chocolate milkshake.

If this is my head gasket, how urgent is it that I fix it? Can I limp along for another thousand miles before I get to it?

And can this repair be done with the engine still in the car?

 

Let's say it is a head gasket leak. You would not need to remove the engine from the truck, I can't imagine a repair (besides actually rebuilding the engine) that requires removing it entirely.

I would run a compression test and confirm it's a head gasket leak. If it is, driving it would stress the engine even more and you will eventually destroy it if you let it keep going and going.

 

headgasket issue or not, this is not normal and there definitely is a problem
I would fix it ASAP because when you let problems sit, that's when they become bigger and worse

 

Think about the only place coolant can come in contact with oil. Now think about how thick oil is and what it would look like if it came in contact with coolant. If you don't want to believe us take some oil and coolant and put it in a container and shake it and look for yourself.

 

Even if it is just combustion gasses escaping into the coolant (which happened to me) you'll get nasty brown coolant and constant bubbling. My head was cracked though

 

Do a compression test to quickly figure out if you have a blown headgasket. If you don't have a bhg, you can flush the coolant - if you mixed green and red coolant it can gunk up.

 

I'd do a leakdown test, compression may show an issue but chances are if it has been running okay it is a small leak and compression won't necessarily reflect that.

 

Sure. Chances are one of the heads is coming off...

I blew a hg and had a good bit of gunk in me coolant.

Next time replacing a radiator OP make sure to flush the coolant completely and make sure to only use one kind of coolant - red vs. green vs. orange. It sounds like you could have two different issues - air in your coolant system and a bhg if you already saw similar stuff in your coolant - leak down test equipment can be rented for free from parts stores...