railguy wrote:
The viscous heater actually serves two functions. The one mentioned in this thread is that of assisting the engine to warm a bit faster. But the second function is the reason why I keep mine connected on my CRD--the viscous heater also serves to help keep the engine warm when the engine is operating in very cold weather or when extended idling. I don't like to extended idle any vehicle, but it is occasionally a necessity for me in very cold weather. Concerned about "wet stacking" when diesel engine temperatures drop too low when idling in very cold weather, I spoke with a Chrysler factory tech several years ago about it. He said that a primary reason for the viscous heater was to put a cooling CRD engine in very cold weather under enough load to maintain operating temperature--without resorting to elevating the idle RPM. In my experience with my '05 CRD (bought new and run in a lot of cold weather), the viscous heater functions just as designed. My CRD will maintain temperature--even when idled for extended periods in subzero weather--without the idle speed increasing.
As for the block heater, I've never bothered using mine, unless the temperatures are below 0° F. If a CRD is not starting easily at temperatures above 0° F., it's got issues.
I totally agree. If the viscous heater is working correctly. There should be no changes in temp between idle and highway when cold out once then engine is warmed up. But a lot of us have this issue. I think its time to make sure its working?
As for using the block heater. It makes for easy smooth starting. I have started my CRD at -6F after sitting for 3 days in the mountains.
As long as the battery is good they should start.