Benzmac, I would agree but I did an experiment. monday morning low to mid 20s car was cranking and cranking would not start. Opened hood, removed the breather hose, started. Next morning, even colder, removed breather hose. Car started first time. Wednesday morning. did not remove breather hose. Cranked for 5 minutes with no success and then removed breather hose car started right up. Each time i would cycle the glow plugs 4 times. I have never heard of anything like this before. Any ideas at all. I like the fact I know it will start in cold weather, but would like to understand why.