Slowly losing coolant

[ScottyBoy]

I'm slowly losing coolant. About a quart every 2-3 months. Been going on for a little over 6 months now. No visible leaks anywhere, but I'm assuming with a leak this slow that it's either internal or it's seeping out so slowly that it will be hell to find it. A similar thing happened a few years ago, but it was leaking a bit faster. About a quart a month. It turned out to be the water pump leaking at the weep hole. So naturally, that's the first place I looked this time. I keep looking down under there with the engine cool, warm, and hot, and I see ZERO dripping or even seepage. Any other places I should look? I wish I had the money to fork out for one of those UV leak finder kits, but money is really tight right now.

 

[thechevyman]

Could be the radiator. Take off the top shroud so you can get a good look at the rediator. Look for stains or discoloration indicating a leak. A small leak could be evaporating.

If its a head gasket just watch for overheating. You could also check your spark plugs to see if any of them looked different.

 

[ccapehartusarmyINF.(ret)]

check around your water pump

 

[M Hankel]

Check the casting number on the cylinder head. If it is a 706, chances are that you have fallen victim to the Castech cylinder head problem. Google it and you will find more bad news.

Mike

 

[ScottyBoy]

I thankfully do not have the dreaded Castech heads. I verified that last year when I changed my valve cover gaskets.
But I guess I will inspect both the water pump and radiator for any signs of leaks or even stains. No sign of coolant in the oil (or at least on the dipstick) that I can see. But I did see some leaking/seepage around my AC compressor. Does not look like coolant though, looks like compressor oil, and it has a greenish color to it. My coolant is not green, I have the orange Dex-cool coolant.

 

[YukonXL04]

I'm leaking some as well. However mine oddly enough is the water pump gasket not the weep hole. It's hard to find wet spots cause it leaks down behind all the acc on the front of the engine. However mine leaves about a 2 inch wet spot on the ground every morning.

 

[chevync]

Your inside windows fogged up in the mornings? If so, could have a small leak at the heater core...

 

[M Hankel]

I thankfully do not have the dreaded Castech heads. I verified that last year when I changed my valve cover gaskets.
But I guess I will inspect both the water pump and radiator for any signs of leaks or even stains. No sign of coolant in the oil (or at least on the dipstick) that I can see. But I did see some leaking/seepage around my AC compressor. Does not look like coolant though, looks like compressor oil, and it has a greenish color to it. My coolant is not green, I have the orange Dex-cool coolant.

That's good that you don't have the castech heads.

Could be a head gasket going bad. I've seen/heard of them leaking a little bit at a time, not enough to cause white smoke etc... How's the oil looking?

As mentioned, could also be a heater core leaking inside the cab. You'd probably notice that though.

Mike

 

[bottomline2000]

yeah, you don't want the 706 crap.. mine leaks like no end. compression loss and all that fun stuff thanks to some crap heads. RTV the water pump gaskets and the leak should be gone...

 

[M Hankel]

RTV the water pump gaskets and the leak should be gone...

RTV on an LS water pump? New stock style rubber impregnated gaskets. I've reused the ones on my racecar dozens of times without a single leak.

Mike