Help me identify black good in pink coolant

Black goo in my pink coolant. 2005 Tacoma 4 cylinder with 355,000 original miles. No signs of coolant in oil. No frothy oil or write froth under oil cap. Still might be headgasket?

Changed radiator last year. Got new upper and lower hoses (from Toyota) with a Denso radiator (rockauto)

Never overheated or even a rise in temps.

 

That's odd. I would guess it came from the new radiator or perhaps the hoses, maybe part of the manufacturing process?
Did you change coolant with the new radiator? Has your cooling system received regular service?
You could do a compression check quick and easy, also there are test kits that tell you if exhaust gas is in the coolant -- these could help you rule out a head gasket.

 

Sure looks like motor oil to me.

But contrary to above, if it is the head gasket, this will NOT result in lowered compression, or exhaust gases leaked into the coolant, because the fact that there is oil in there indicates that the problem is *not* between the water and the combustion chamber. If it is head gasket, then its between an oil passage and water.

Could also be a cracked block. I'm not sure where all the different places are that oil and water come near to each other. The odd thing about this is that usually you would expect coolant in the oil as well.

 

smell it does is smell like oil? looks like oil.

 

Really hard to tell. Can;t really smell it. Its like tar. I have a friend tearing into it now. A cylinder compression test resulted in the coolant bubbling. My money is on gasket leak.

 

Pull the plugs and use a bore scope.

 

Was the black sludge there BEFORE you put on a new radiator and hoses?

 

Negative. That was over a year ago.

 

Is it possible the new radiator hoses had been stored incorrectly? Basically once you put them into operation, the inside coating of the hoses has started to sludge off?

 

Burp the system with heater on high. See if bubbles come up. Compression test shouldn't produce bubbles if there is no bubbles when it's running. My guess, you were only really looking at the coolant when you were doing the compression test, never really looked while it was running normally.

If you want to test it, hook a shop air compressor (with adapter) to the suspected cylinder. Rotate the crank to close valves. With valves closed, if you see bubbles, bad HG or cracked block.

Also like mentioned above, use bore scope, scope the cylinders. If one looks like its been steamed cleaned, it has been. Coolant burning off "steam cleaned it". So HG or cracked block.

 

If you didn't burp it with heater on high after changing coolant, you will have bubbles in the coolant system. Could simply be from that.

 

Time for a rebuild.

 

Did you by chance add some sort of radiator/cooling system sealer when you installed the new radiator?

 

They look like Barr's Stop Leak pellets. When the old radiator went out, did someone maybe use a bottle?

 

Didn't catch that post. This is strange to have oil and no coolant changing places.

 

Nope. I am the only owner and driver. Not going to rebuild. Replacing associated gaskets and hitting the road. Next big expense.... I'll prob sell it for scrap.

 

Overflow bottle isn't air tight by any means - gunk from the engine compartment can and does get in there.

I would pull an oil sample and send it to Blackstone Labs - they can detect even trace amounts of sodium and other elements in the oil that will indicate if you have a HG issue or not.

Do not pull the head if you're not 100% sure it needs to be - my experience has been that it's difficult to get a proper seal again without machine shop work on both the head and block.

 

Send a sample toBlackstone Labs