coolant question (not ford related)

how can a motor get coolant into the exhaust while running but when you pressurize the cooling system there are no leaks? Plugs show white residue. This is a 4 cyl mitsubishi in my bobcat. Want to diagnose before dissassembly. If it was a cracked head or blown head gasket then i should loose pressure when i pump up the coolant. There is no water in the oil. this one confuses me.

How often are you adding coolant to the machine?
and are you doing the pressure test when its hot or cold?
is it gas or dsl?

only added fluid once, but i quit using it once i noticed the problem. Testing cold and its a gas.

Combustion Leak Detector



LISLE

75500 Back
Combustion Leak Detector
Quickly Pinpoints Combustion Leaks.


Checks for combustion leaks caused by bad head gaskets, cracked blocks, and cracked or warped heads. Fluid changes from blue to yellow when exposed to combustion gases from the radiator. Connect the hose to any vehicle vacuum line. Or, on tools made after June 2002, use the red adapter with a hand vacuum pump. Place tapered end of tool into radiator opening. With the engine running, the vehicle vacuum or the vacuum pump draws vapors through the indicating fluid for testing.

Available Individually:

75630 Replacement Fluid - 16 oz.



Suggested Retail: $45.05
UPC Code: 083045755005
Found In
Tune Up

any local parts store should have one or get one next day

You might not have a leak until its hot and things expand. and it sound like a really small leak.

thanx for the help, as you say maybe the leak starts when hot? I may just trying to figure out the theory behind how you can have coolant getting into the exhaust but the coolant system wont lose pressure even after leaving the tester on for 24 hours (unless it only happens when hot)