Blown head gasket?

I also spoke with the previous owner today about this issue. He said he had tried to change the thermostat, but had abandoned the project when he couldn’t find one to replace it with. He said he also got oil in the cooling system from the transmission cooling lines that run through the thermostats housing area. He cleaned it out as best he could, but always had foamy coolant in the overflow tank after that. He assured me there was nothing to be concerned about, but did say I should change the thermostat.

The whole story sounded crazy to me. Does this make any sense to anyone?

I also took a video of the overflow tank being stirred up. Is this just from coolant returning to the tank? It’s kind of dark, sorry.



https://youtu.be/CmI8UxDwDX0

there is no air in system only antifreeze so I don't see how soapy water would find anything? the bloc chek only requires 2 or 3 pumps to show what it finds, very quick. it will find a gasket leak that you don't even know about. sounds like you have nothing wrong.

I am sorry you misunderstood me, The only place air would leak out are the cap and the fittings on the top back end of the exp tank and a foot or so of hose, as those are the only thing above the coolant level. And if the coolant level didn't drop under pressure, you are not loosing any coolant...

The trans oil lines don't run anywhere near the thermostat the only place you could get transmission oil into the cooling system is from the transmission cooler below the front of the engine. A leak in there should have shown as a coolant loss when you pressurize the system though and of course a gain of fluid in the transmission...

The flow in the expansion tank is normal as the top rear line on the exp tank comes from the thermostat housing. The bottom hose goes to the water pump inlet side, so fluid is being pumped to and from the exp tank whenever the engine is running...

So what is my next course of action? The coolant is definitely frothy. Was thinking drain and fill with water and a few cups of purple power to clean things out, then drain and fill again with water, then drain and fill with 50/50 anti freeze.

Asymair95 said:

So what is my next course of action? The coolant is definitely frothy. Was thinking drain and fill with water and a few cups of purple power to clean things out, then drain and fill again with water, then drain and fill with 50/50 anti freeze.

Click to expand...

Let run with the hose in it to flush out. Cap the drain. Let sit for 10min. Open drain to empty. Close. Refill with water and cascade dishwasher detergent. Run for 20mins. Drain repeat as needed. Cascade does wonders

I ordered a new thermostat and gasket, will flush and clean the system during the change. Will report back with results.

As one final check I performed the “bottle test” today and it passed...no bubbles from the coolant overflow hose.