On a 1999 300m -Finally successfully diagnosed combustion gas leaking
past my head gasket into coolant causing overheating. Used the Napa
Block Test kit for $50. Many posts say go to your neighborhood garage
and get them to use an exaust analyzer - dont know what that would
cost.
My Napa Store did not know anything about this test kit and could not
find it on their computer so here is a site and part number you can
show them
http://www.arrowheadradiator.com/hea..._leak_test.htm
part number700-1006.
Be sure to drain a few inches of coolant before installing this thing
on your radiator (or pressure bottle) opening. . Keep watching the
tube as the car warms up and gases go through. If you have combustion
gas, the fluid in the tube turns yellow.
Now, about that head gasket...