One thing, the Isuzu was driven from Anchorage to Kenai one day(150 miles) when the weather temp was -35 degrees. The driver complained about not being able to get any heat the whole trip. Said he nearly froze to death. Of course a cold heater immediately makes the cooling system suspect, and sure enough, when  the radiator was checked, there wasn't a drop of coolant in the system. 

The drive with no coolant never seemed to have any impact on that engine.

John Rodgers
"88GL Driver

jsnyder wrote:

Hi My diesel Vanagon has never seen temps below about 30 degrees in California. Now that I am in Virginia, I will need to keep it running (and starting) down to the low 20's and occasionally below that. It has been starting a little hard currently around 30 degrees. I plan to replace the glow plugs soon and probably the 60 mo. battery which is a few years old now. Do any list members have other suggestions? Can I use one of those oil dip stick heaters? The engine is slanted which makes this option seem impractical. I have also just switched to 10W40 Castrol GTX from 20W50. The engine runs great when warmed up. Many thanks in advance. Jim Snyder