Hello,

Son blew head gasket after head bowed after loosing coolant and overheating. No obvious signs of coolant leakage :pump leakage, hose leakage, no drips from obvious suspects;except for the coolant squirting out of the head gasket. So I put more coolant in and after the head cooled it didn't leak...drove it home.

Next week had a junkyard head rebuilt and installed it with new gasket and all other sundries. Old head was definitely passing coolant through engine and could not be reused.

The car stil looses coolant with NO obvious signs of loss at all hoses including the ones leading to the heater core, nor is the heater core leaking. I don't know what to think.

Now, the only thing I do see is a small collection of coolant on the intake side of the block in one of the block plugs closest to the front of the block. And by plugs I mean indented circular blanks, that I suppose are for other uses, I'm not sure what, but I don't see anything leaking above it causeing coolant to pool in the indented block plug.

At first we thought it was an air bubble so we added more coolant and we've done so every week, filling the low resivoir. What is going on? This is a water cooled turbo but no signs of leakage there. Is there someplace that I'm not inspecting? HELP, at a loss.

Best, Josh

I have simply pasted my response to a post concerning a coolant leak from yesterday. It will be hard to pinpoint some leaks without pressurizing the cooling system....

A pressure test would be the easiest way to find the leak.

Otherwise top up the cooling system and bring the car up to operating temperature Finish with a "hot run" working the engine rather hard. The kind of drive that causes that telltale pinging of cooling components under the hood at shutdown.

With the engine hot and no circulating coolant the temperature will rise. Pressure will increase as well. Go over the entire engine compartment with a good light looking for seepage.

Don't forget to press your nose into service during the inspection as many times the smell of hot coolant will draw you to the area it is escaping the system.

Did you have the head checked for both cracks and for plane and milled as necessary before installing it?

With the pressure in the system have a look at those freeze plugs. They rust internally and pinholes can develop. Good luck.


Randy

The thermostat housing gasket can leak, or small pinholes can form in the head/housing interface from corrosion, causing leaks. Sounds like that's the right area to look.

The plugs I refer to are the freeze plugs. I wiped the pure coolant off that was accumulating on the front one to see if it occurs there again. Haven't pulled back the carpet to see if heater core has leaked but son says he has heat. There is not chemical/coolant smell in car. WTF?

Josh

Try replacing the upper radiator hose. It may have a pinhole leak.