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cracked head?

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Stewart

Stewart

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My 75 has had a habit of drinking water. Over christmass when I was last home I found a bad radiator cap and dco forgot to tighten up the heater hose to the heater valve. I fixed the 2 leaks and drove it another 100 miles or so where it then drank more water than I've seen before close to 1/2 gallon. Prior to this it used about that same amount over 1k miles. Car was still running a couple needle widths to the left of the N.

The oil is super clean and clear none of the normal gack under the cap. I refilled the radiator opened up the heater valve and topped off it off after the t stat opened. However with the cap off the water was fizzing like a coke in a glass after 5 minutes after pouring it with a big bubble every once and while.

Should I be planning on pulling the head next week when I'm back or should I be looking for another external leak?
 
Could be a head gasket as well. Either way it sounds like a bit of work is in your future. I'd suggest a compression test.
 
What I would rcommend is a pressure check tester, it's device that hooks up to your radiator cap and you pump it up and if the system holds pressure it will show it on the gauge of the tester, then you're ok, and if not you have a problem, if the leak in the system is external, then you liable to see as well.
 
if you rule out external leaks per haps suggestion you could swing by your favorite repair shop and have them put the sniffer from an exhaust analyzer right at the radiator neck(not in any coolant). any co/ hc there and you'll have to pull the head. that's saved me a ton of time searching overheationg problems in the past. hope it helps
 
The good news is that in all likelihood you do not have a cracked head. Leaking water pump, heater core,
hoses, or radiator core are all good suspects. Do you smell coolant at shutdown? This would be a good indicator if it is a simple leak.

Jim D
 
There's also a more modern test for testing for a blown head gasket, it was just becoming popular when I got out of the general automotive repair business. The test uses a liquid, that when mixed with your coolant will turn colors if there is presence of carbon monoxide.
 
Finally got my hands on it. No external leaks compression was 130 120 105 130. Looks like I'm going to have some fun on friday.
 
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