Questions and Answers
I did have a bad head gasket that I replaced 4 months ago. Three months prior to replacing the head gasket I was loosing about a quart of engine coolant per month. Since there was no coolant on the garage floor I figured it was going into the crankcase. One day the gasket finally let go. The car was immediately turned off when it started to bellow steam out the exhaust pipe. The car was towed home and a new head gasket installed. The head was pressure checked and the mounting surface was machined flat.
Moisture In The Crankcase - Revisited
Q. I have a 1993 Pontiac Grand Am with a 2.3 liter Quad four engine. I contacted you about a week ago that I was having a problem with condensation in the crankcase. Your reply was a possible bad head gasket or a faulty PCV valve.
After replacement of the head gasket I have not had a problem loosing coolant, but I still have moisture in the crankcase. It shows up on the dipstick and in the hose leading into the air/oil separator. This engine has no PCV valve, instead it has an air/oil separator. There is a tag in the engine compartment that shows the routing of all the hoses leading into and out of the air oil separator. Everything is routed correctly. The hose from the top of the chain case cover into the air/oil separator always has water droplets and a milky substance in it.
The Haynes manual say's to replace the air/oil separator when moisture is present in the crankcase. I went to my local Pontiac dealership and spent $30 on an air/oil separator that was installed about four weeks ago. I changed the oil at that time and got nothing out of the crankcase but 4 quarts of dirty oil.
The engine runs great but I am concerned about the moisture on the dipstick. The car is driven daily and has at least 2 hours of driving each day. My thoughts are the moisture is from condensation but I would think it would be boiled off the oil, with the amount of time the car is driven daily.
Any ideas on this problem would be greatly appreciated.
A. This is very common on all of those engines. Usually it is indicative of a bad head gasket and it is wise to check it when it is suspect.
Basically, in my opinion, it is due to a flaw in the design of the engine. For some reason GM did the crankcase ventilation system differently. The only flow through the oil/air separator is the combustion blow-by, as there is no fresh air inlet to the crankcase. The oil/air separator causes oil, which may be suspended in the blow-by gases, to be separated and drain back to the crankcase through a hose to the oil fill tube
This lack of a fresh air intake is what causes the condensation to form. Since there is no way for the water to be "dried" out the air/oil separator just dumps it back into the fill tube which is why you see water and milk in that area.
I had thought about trying to convert one of these engines to a standard PCV system, but I can't find anyone willing to be a test subject.
