318 head gasket leak?

[CaptainSteve]

Status: Clean/clear transmission oil cooler.
Clean/clear heat exchanger.
new 170 degree thermostat.
50/50 coolant verified with a test
New impeller
Runs @ 170 up to 2600 rpm
2800 will bring temp to 180

3000+ rpm will hit 200 degrees in 1-2 mins.

Bubbles in the coolant reservoir at idle:

https://photos.google.com/share/AF1QipN ... ZjUERlSDlB

[prowlersfish]

Possible you can buy a tester for combustion gas in coolant .

[paskyhawk]

Is there any history of a broken impeller parts that could be restricting the coolant flow?

Rich

[CaptainSteve]

Re: 318 head gasket leak?
Unread post by paskyhawk » Sun Jul 28, 2019 7:07 pm

Is there any history of a broken impeller parts that could be restricting the coolant flow?

Rich


I did find impeller parts a while back in the heat exchanger. Mind you that only RSW passes through the impeller. The circulation pump which has a brass impeller is what moves the coolant through the block. The rubber impeller moves the RSW that cools the coolant. I can only surmise that an overheat has caused a slight head warp or gasket deterioration thus allowing combustion gas to pass to the coolant passage. Next check will be the chemical tester in the coolant.

[paskyhawk]

I only ask because last time I had and impeller breakapart, surprisingly, all the pieces were on the inlet of the raw water pump. The water must’ve stopped pumping and the pieces must have fallen by gravity down the hose.

[WayWeGo]

You can get bubbles in the coolant of an engine if the cooling system is not pressurized, because the coolant can boil if the radiator cap does not hold pressure. I don't know if that is what you are seeing, but if the engine is already hot, that is always a possibility.