Before and after 150 watt oil pan heater. Guess?

[Gasbuggy]

I installed a Kat's 150 watt stick on heater tonight on my Cadillac CTS-V. Would you guys like to guess how many degrees F my cold oil temp will increase as a result? I'll take three measurements; before and after 1 hour, 2 hours, and then I'll leave it on until it maxes out temp.

Here is the oil temp sensor location, pan has 7 quarts of oil in it. The pad heater covers about 40-50% of the surface area of the sump bottom.

I will wager my own guess, assuming cold oil around 10 degrees.

1 hour: +30 degrees
2 hour: +51 degrees
max: +70 degrees

I've always been a fan of devices that help pre-heat your engine. I have messed around with stick on heaters in the past but this is the first time I've owned a car with a digital oil temperature sensor. We've had a very warm winter until recently. Recently my Cadillac had it's first cold start with M1 0W40 in pan and with the oil temp at -7 F my low oil pressure light came on after start up and stayed on for several seconds. I've never seen that happen with any of the various 5w30's I've ran, even when the car sat for a week in New Hampshire and was started at -15 last winter on fresh 5w30 PP. Different oil filter at the time, was running AC Delco and currently have a Tearolater Pure One on there.

 

[Shannow]

Can you take another picture with an inch rule for reference, and similarly the square inches of the pad ?

 

[eljefino]

I bet it raises your oil temp 15 degrees but the pan will conduct heat to the probe so it looks like it raised it 30 degrees. But after you start and run it the temp will dip down near ambient. Of course you could then say the oil is stealing the cold from the rest of the engine.

 

[dlundblad]

Originally Posted By: eljefino
I bet it raises your oil temp 15 degrees but the pan will conduct heat to the probe so it looks like it raised it 30 degrees. But after you start and run it the temp will dip down near ambient. Of course you could then say the oil is stealing the cold from the rest of the engine.


Would an oil pan heater that adheres to the entire bottom of the pan be better?

 

[eljefino]

I think one that puts more BTUs in your pan would be better. It all gets conducted up, around, and into the oil anyway. A 1000 watt soldering iron would rock as long as it doesn't melt the aluminum.

 

[d00df00d]

Originally Posted By: eljefino
A 1000 watt soldering iron would rock as long as it doesn't melt the aluminum.

Or cook the oil!

 

[BR17]

1 hour: +10
2 hour: +22
Max: +51
I don't think 150 watts is going to do much. I would put a Moroso 5x7 500 watt element on the pan. I used to run two of these on a 14 quart dry sump tank and I could get the oil up to 180 degrees in about an hour and a half if I wanted to. 140 degrees in about an hour. Not the same situation, I know, but a 500 watter would make be a noticeable improvement.

 

[Trav]

I left the two150w on my Expedition on overnight (one engine and one trans) and it raised the temp 30f over ambient.
They made the world of difference. The transmission had noticeably better cold shifting.

 

[demarpaint]

Originally Posted By: Trav
I left the two150w on my Expedition on overnight (one engine and one trans) and it raised the temp 30f over ambient.
They made the world of difference. The transmission had noticeably better cold shifting.


+1 on the transmission pan heater. I have both and it makes a lot of difference on cold days. Leaving it on for extended periods of time isn't going to cook the oil or the ATF so no worries there.

 

[meborder]

I put a 500 watt magnetic heater in my oil pan 2 winters ago one night. It was about -20f and -35ish with windchill. The vehicle was parked outside.

In the morning when I pulled the heater off the oil pan still had frost everywhere except the few square inches where the heater sat.

I have not bothered since.

They work and work well .... In a garage, but Just not outside.

I don't think a 150 watt heater will be worth messing with, but I could be wrong. A better use for that heater, imo, would be under the battery.

 

[eljefino]

I have a 300 ish watt magnetic pan heater and use it when it hits below -10F because every little bit counts. But being in an unheated, uninsulated garage on top of a concrete slab (that holds heat) counts for more, IMO. As Zoidberg would say, why not both?

For me, the power steering is the loudest thing when it's that cold, though I'm happy it cranks over and starts.

 

[JHZR2]

Figure the specific heat of oil is 2kJ/kg*K

Figure 6 quarts of oil weighs 4 kg.

Figure the heater has to heat the ambient (poor insulation and no guard heater), and the metal, so efficacy is maybe 30ish%.

So 50W going in means 50J/sec.

Every 20 sec maybe 1kJ.

Need 8+ kJ to raise 1 Kelvin.

So 1K every 160 secs.

So after 1 hr around 20K, which is a factor of 9/5 so 38ishF? Seems about high but the engine thermal mass and losses are a total swag.

As it warms, delta T with ambient will increase so losses will go up until some steady state is obtained.

I'm scratching this at breakfast counter in a restaurant do someone can check my conversion and math.

 

[demarpaint]

I have a 250W Wolverine oil pan heater. Recently I wanted to see how well it did. Ambient temp in garage was 27F not cold by any means, but that was the temp the day I did my checking. I had it plugged in for 3 hours, my coolant* temp was 85F when I turned the key, and after 1 minute of run time and about 100' drive to the end of the driveway I was up to 111F. If we ever get some cold weather I'll do some more testing, and plug in the block heater as well to see how both do.

 

[Garak]

Anecdotally, I've had good luck with some oil pan heaters. I'd have to check their wattage next time I'm in the garage, though. They did make a noticeable different in starting on the worst days. Now, I have no idea how many degrees it warmed the oil. Even a few degrees makes a difference when you're pushing the CCS and/or MRV temperatures of the grade.

For what it's worth, I would not want to be touching the face of my magnetic oil pan heater when it's plugged in, even below -35 C on an oil pan. Taking it off once, I fumbled with the thing and regretted it.

 

[compratio10_5]

My nephew's car sat in the driveway over Christmas vacation in subzero F weather. The engine oil would not readily drip off the end of the dipstick when I checked it so I put my 150 watt Kats heater under the oil pan for about an hour and then rechecked the oil fluidity. The oil then readily ran off the dipstick and the car started fine. I believe that these oil pan heaters are the most effective use of electric energy that you can use on a cold vehicle and it is quick too . I suppose that wind velocity and oil sump construction (cast aluminum?) will have a large effect upon oil temperature.

 

[stockrex]

hmm, I am MI and it gets down to -2xF here,
I just put in any brand full synthetic oil, voila.

heaters are so 70s ;-)

check the pour point of oil, change to one with lower pour point.

windchill does NOT do anything for oil

story time:
I have not parked in a garage for the last 10 years, I rarely warm a vehicle.

maybe it is better to put in a thinner/synthetic oil than a heater in terms of cost/aggrevation etc.

 

[Neely97]

In the photo, I do not see a stick-on heater pad. What am I missing?

 

[Brybo86]

Originally Posted By: JHZR2
Figure the specific heat of oil is 2kJ/kg*K

Figure 6 quarts of oil weighs 4 kg.

Figure the heater has to heat the ambient (poor insulation and no guard heater), and the metal, so efficacy is maybe 30ish%.

So 50W going in means 50J/sec.

Every 20 sec maybe 1kJ.

Need 8+ kJ to raise 1 Kelvin.

So 1K every 160 secs.

So after 1 hr around 20K, which is a factor of 9/5 so 38ishF? Seems about high but the engine thermal mass and losses are a total swag.

As it warms, delta T with ambient will increase so losses will go up until some steady state is obtained.

I'm scratching this at breakfast counter in a restaurant do someone can check my conversion and math.

I haven't done any physics equations since high school but this looks/sounds good to me!
Glad we have you around here, adds some data to the conversation rather than just opinion.

 

[justinbaileym]

I remember reading the packaging on some oil pan heaters and they say to put them on after you're done driving to "keep the oil temp up" I don't think they are designed to warm cold oil, only keep warm oil warm.

If nothing else it may be an interesting data point, do a cold run and then stick the pan heater on when you're done driving to see if it keeps the oil warmer.

 

[Rand]

Those numbers look in the right ballpark but the losses are obviously a WAG

IT would be heavily vehicle dependent + outside temp and wind would vary it widely.