Chevy 3.8 is loosing a pint of coolant every 3 days no visable leaks oil looks fine I assume a bad head gasket

I'm going to be honest with you if you add this stuff to your car you will make the problem worse probably because it will clog up the heater core as well and parts of the cooling system also,and make it run a lot hotter,your best bet is to not add anything to it,that stuff doesn't work too well,it winds up costing you more than its worth to use it,id rather have to add the anti freeze to it as have that in it,your best bet is to just have it repaired,good luck.

i'm a journeyman and characteristic over 15 years in with GM. start up with a compression attempt as which will inform you if the top gaskets are good or no longer. the three.a million liter engine does have a historic past of intake gaskets leaking. in case you look into the 4 outdoors corners of the intake you'll locate coolant leaking. if it extremely is the case, you'll favor to change the intake gaskets. at the same time as the intake is off, reseal the cap it extremely is the oil pump force off the camshaft. that's good lower than the thermostat housing and also you'll locate that that's leaking oil. you ought to thoroughly flush the crankcase to get each and each and every of the coolant out or bearing harm will take position. i trust flat price time on that activity is approx 6 hrs. also, The intake and exhaust pushrods are different lengths and in case you blend them up, the engine received't start up, or have a nasty missfire that would want to harm the valves. Get a guide for this engine and also you'll do precisely positive. Bleeding the air from the cooling gadget is likewise a particular proceedure yet is actual finished in case you persist with the teachings. good success.

If you had a bad head gasket there would be more symptoms than coolant loss. You could have a leaking freeze plug in a location that isn't very noticeable. The coolant vaporizes and forms a slime on the block. There's a product called Bars Leak. It can block radiator passages though.

It is losing coolant while under pressure or you would have a puddle. Check the thermostat housing (waterneck) and do a good hose check. A pinhole in a hose or a hoseclamp that has rubbed a small cut would explain the coolant loss while the system is under pressure but no puddle when not as well.

You can try any of the radiator stop leak products also.

I think your assumsion is right and it is a blown head gasket, the cooant maybe just burning away in the cylnder so your oil will never look milky, try to smell your exhaust for coolant smell, but I would do a cyl. leak down test to be sure. And no, do not add anything to your radiator like (stop leak) it just more trouble later on.

if the engine has the plastic upper intake manifold on it there is a passage that the coolant runs through and this passage can rot out and the coolant can go into the air intake section of the lower intake and go into the combustion chambers along with the air. you should check the upper intake manifold.

Have a good mechanic check it for coolant getting into oil from intake man. gasket also.