Ford Repair: Moisture in crankcase - 99 Expedition, blown head gasket, losing coolant

Question
Hi Dennis, I have a '99 expedition 4.6 with 230,000 miles on it.  In the winter time here in Minnesota, I notice I get moisture in the crankcase, or at least I get foam at the top of the oil filler.  the vehicle runs great, and is not missing on any cylinders.  I occasionally get a CEL on the "bank 1 too lean".  I had previously ran low on coolant, the vehicle did not overheat. I noticed a small hole in the radiator which was promptly replaced. Again, I notice the moisture only in the winter time when the heater is running. of course my first thought is cracked or blown head and or gasket, but only in the winter? I can put a compression tester on this but with that many miles, I'm sure compression will be down across all cylinders.  the tester would pinpoint a cylinder or 2, but are there any thoughts on this other than a cracked or blown head gasket?  Thanks  

Answer
Hopefully you are doing regular maintenance on this engine, ie oil changes etc. If it is not losing coolant, probably not an internal issue like a head gasket. Make sure the PCV system is working properly, some of these engines can split a PCV hose or rubber elbow causing not only a vacuum leak but also an inefficient PCV system. Any thing that reduces PCV action can lead to what you are seeing in the filler neck, just as lack of maintenance can do. The fact this only occurs in winter may just be a result of the temp differences between the engine and the atmosphere, especially in Minnesota. I see some of this buildup here in Colorado on high mileage vehicles, more so in cold weather.

Short trips can aggravate this condition, so you want to get some highway miles on it with the engine hot. Does it seem like the engine may be running cooler than normal? Possible that too low engine temps can cause this build up also.

Mostly I would pay attention to the PCV system, and get regular oil changes with quality oil and oil filter.