When to use the engine block heater

[efstewart]

On my prior motorhome (2006 Dutch Star), I did not have an engine block heater, and I had no problem starting it in cold weather. On my Country Coach Intrigue, I have one that can be heated either with the diesel hydronic boiler or electric. Please tell me when I need to use it and when I don't. Is it only for extremely cold weather? And when and for how long do I need to use it prior to starting the engine?

BTW, both motorhomes have the Cummins 400 ISL.

[Smitty77]

I admit, and my DW was confirm - I do things differently!

Our ISL in mid 30's and above, starts quite well without preheating. (I will at times, if say 32-35 outside, go thru a 2nd 'Wait To Start' light going out, for the manifold heater to get to shots of, well - manifold heating. Key on. Wait to start light goes out. Key off, and right back on. Wait to start light goes out, and start engine.).

30-32 and below, I'll use the engine preheat loop from the Hydro/AquaHot. Either by Electric Heating Element only, or if using the unit for coach heat and taking a shower before departure - will fire off the Diesel Burner too...

I do know that many wait to the mid 20's before being concerned about pre heating the engine block before starting... But I figure why not use it...

And a side note. When I'm up in the early hours before dawn for a call of nature, I'll also sometimes use the Block Heater loop, especially on Electric Element from in our coach the HydroHot. The engine block heating up a bit, eventually radiates up thru the bedroom carpet and warms the bedroom a bit more. (Of course if really cold, and on 50A shore power, I'd have had the Floor Heat on by then anyways...).

These mid size blocks, do a good job of starting in cooler temps!

Best to you,
Smitty

(CAPS ERA ISL)

[CoCoDave]

I don't know if my engine ever needed the block heater to start but I usually turn it on for an hour, give or take, if I remember, before starting. My thinking is that it shortens the warm-up time of the engine. I try to minimize idling, particularly in an RV park. So when I turn the key on, the engine is already in the vicinity of 90 degrees, depending on outside air temperature.

Iin the time it takes DW to dash outside and to the back of the rig to look at the lights as I cycle through them (left turn signal, right, emergency flasher, brake, etc.) we're rolling. DW follows on foot to make sure all's good with the toad hook-up. I stop, she jumps in and we're off. All in under 4 or 5 minutes and by the time we're on the highway the engine is usually well over 115 degrees. I go easy until it nears the low end of operating temperature, around 170 - 180, degrees before using much throttle.

It's a long-winded way of saying I use the block heater to get us going faster. Is it hard on the block heater? I don't know. But I don't read about a lot of them going bad. In trucks, in some climates, I imagine they stay on a good bit of the time the engine is not running.

FWIW

[Bigd9]

I use the block heater when temperatures are in the 30's and below. One thing to note, unless your engine has a oil heater, the oil temperature remains as cold as the air around the pan, and takes a while to warm up after the engine is started.

[Old Dinghy]

I regularly use the block heater in temps under 40 degrees, and start-ups are easy and quick. As an aside, we were parked at -5 degrees with a wind that made the windchill -20. A nearby Country Coach started his engine every couple of hours, all night. I thought he had some type of issue, but the next morning he started and drove away. I started right up, but quickly the engine stopped. Long story short, our fuel had gelled in the extreme cold, and I am told that Cummins engine circulate more fuel than they need, so the smart camper had kept his fuel from gelling by routinely circulating it every couple of hours. I will make every attempt to avoid those conditions in the future, but it was a real dilemma at the time. Safe travels. Stay warm.

[Smitty77]

I really appreciated the info sharing on this thread. I usually do my best to avoid the extreme sub zero temps!

Spot on in our on the engine is up to operating temperature faster. And found myself nodding my head about the thin oil pan transferring coolness to the oil (Suspect the warming block helps some, but still the oil will probably be cooler.). And starting the engine periodically to sort of stir the fuel tank, was good into too...

To the best of my memory, my coach has never had Winter Bled in it. But I do keep Optilube's Winter in my traveling arsenal... Using it once, filling up at Toad River before Camping along Muncho Lake - we were into the single digits many nights, and always down in the teens overnight.

Best to all, and thanks for info,
Smitty

[DJ55]

When the outdoor temps are below 40, I use the block heater when we're hooked up and/or we rely on the engine loop from our Oasis burner if we're taking pre-departure showers. If we're hooked up, I usually turn on the block heater in the morning as we're getting out of bed, so it runs for at least an hour or two before we start the engine.

I also use Power Service Diesel Fuel Supplement (winterizer/anti-gel) if the temps will be below 30. PS products are pretty easy to find, at most auto parts, farm, and hardware stores.