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Oil Change Question - Oil Pan Heater OK for Preheat?

snopercod

Well Known Member
I need to change the oil in my plane and the weather has been too poor to fly like I normally would to warm up the engine. Is there any reason I can't just leave my oil pan heater on for 24 hours before draining the oil? The entire cowling interior (including the CHTs) gets up to 70 F with it on and the oil temp is bottom of the yellow arc. What do you think?
 
John, I don?t think you?ll need to keep it on for that long. I live in N. Georgia, so similar temps as you, and just did this on my RV7 last week. I turned on the heater for only about 45 minutes before draining the oil and the oil drained fairly easy. You can actually start to smell it as it gets warm enough to drain without it looking like tree sap :D
 
That would get the oil warm but won?t get the contaminants in suspension and is the main reason for running the engine. Can you do a ground run?
 
That would get the oil warm but won’t get the contaminants in suspension and is the main reason for running the engine. Can you do a ground run?

Contaminants are held in suspension by the Ashless disspersent additive and it works at all temps. The debris held in suspension does not fall out when cold or engine not running. If it did, your pan would be full of sludge that would not be removed with an oil change. This is what happens when the debris load exceed the capacity of the AD additive. Pretty much anything that falls to the bottom of the pan will stay there forever. This is why aviation engines have more frequent oil changes. They produce a lot of debris and the AD becomes saturated much faster than a car. you do NOT need to run an engine to put debris into suspension.

The only reason to do an oil change hot, is that the oil drains/drips faster. This makes sense when the temps are down near freezing. It takes a long time to drain the oil.

Larry
 
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Also, most of our engines now have an oil filter. That'll trap the most damaging particles.

I use an oil-pan preheater for oil changes on my C180.

Dave
 
Success!

I changed the oil today just using the heat from the oil pan heater. I decided not to run up the engine because I wanted to see how it would go with just the oil pan heater. It worked fine and the oil was completely drained in less than 10 minutes. My quick drain was hot to the touch - I estimate 105 degrees F. I just wish I had thought to bring the case of fresh oil home to warm up as well. It took much longer to re-fill the crankcase then empty it.
 
I guess the run up before is more important when taking samples for oil analysis. I?ve always done this in the past. All the labs recommend doing it to ensure a representative sample.
 
Does anybody know how to preheat oil in sealed quarter bottles safely? Up to a 100 degrees or so. Car heat doesn?t make it :)
 
I guess the run up before is more important when taking samples for oil analysis. I?ve always done this in the past. All the labs recommend doing it to ensure a representative sample.

That would make sense, as some things that they check for like water and gasoline, possibly others, will stratify and are not held in suspension by the additive package.

Larry
 
I guess the run up before is more important when taking samples for oil analysis.
I'll find out. I drained one quart then took a sample and sent it off for analysis. I've been sending samples to the same lab for five years so I have a good history for comparison.
 
Does anybody know how to preheat oil in sealed quarter bottles safely? Up to a 100 degrees or so. Car heat doesn?t make it :)

assuming you mean while at the airport. I would set them in the engine compartment of your car. If you put them on a warm part of the engine after shut down, it should warm them up well. Maybe not to a 100, but warmer than ambient.

Larry
 
Does anybody know how to preheat oil in sealed quarter bottles safely? Up to a 100 degrees or so. Car heat doesn’t make it :)

I set my oil on one of these heated grow mats with a thermostatically controlled switch that's connected to an amazon wifi switch and my $3 per month (plus taxes, etc) Ting hot spot and I can turn it on the night before I'm going to change the oil. I also have independent switches for my battery charger and engine preheat all connected to the same hot spot. You could probably just set the temp of your oil to 75 and put the entire case on the mat and just forget about it. Your oil will always be nice and warm. I just save a little electricity and use the wifi switch.

https://www.amazon.com/dp/B016MKY7C...jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ==
 
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In my opinion, ground running to warm the oil is the worst option. Draining warm oil is much better than cold oil, as we all know how tedious it is to wait for cold oil to drain, and warm oil will drain more completely than when cold.
 
Vlad, 4 quarts fit on the defroster vents of most cars' dashtops. Direct air blast gets them plenty toasty.

That’s what I did today thanks. OAT was 34F oil level was running low. Added two quarts of warm oil and started on 7th blade.
 
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