Oil temperature - run-up dilemma

Hippike

Pre-takeoff checklist
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Hippike
Two CFIs in the past have told me always to wait for the oil to warm up prior to doing run up. In fact, even the DPE on my CR told me to wait till the oil temp gauge reaches the green (C172).

I’m training for my complex/hp endorsement (T182RG) and the new CFI - when I brought this up - said no need to wait, that only applies to cold weather operations, being in SoCal, we don't worry about this and said something about the oil viscosity.

I still think wait is better. What U think? And why?

Discuss
 
Most of the time in the summer (Denver) the oil in my cherokee is already warmed up from being in an east facing metal hangar.
What does the POH say? Or if you need more details, contact Continental (assuming it's a Cont engine) and ask them.
 
When your engine will accept rapid advance of the throttle, it is warm enough to fly.

every one warns against flying a cold engine simply because of the rapid wear when cold.
 
Lycoming says its warm enough to take off if you can open the throttle without the engine faltering :) You probably have a Continental though. I like to let mine (Lycoming) sit and warm a bit anyway.
 
Neither Cessna nor Lycoming say anything about checking the oil temperature before runup.

Lycoming says:
The Engine is warm enough for take-off when the throttle can be opened without the engine faltering.

Cessna is silent on the issue except for the section on cold weather operation:
During cold weather operations, no indication will be apparent on the oil temperature gage prior to takeoff if outside air temperatures are very cold. After a suitable warm-up period (2 to 5 minutes at 1000 RPM), smoothly accelerate the engine several times to higher engine RPM. If the engine accelerates smoothly and the oil pressure remains normal and steady, the airplane is ready for takeoff.
 
Some people use unofficial rule to wait till at least 80F before run-up. After run-up the oil is presumed to be warm enough to take-off
 
Some people want the time on the Hobbs to keep clicking while you sit and wait for the oil to heat up.
 
I'm not concerned about the Hobbs (let's say it's my plane).
I am thinking more about the various metals' characteristics at various temps. I'm no chemist/metallurgists but I know that different metals expand/contract at dif. temps.
So a cold engine has more friction and therefore experiences more wear as opposed to a warmed up engine. Or does this only apply during extreme cold temps, like 0/32?

Some people want the time on the Hobbs to keep clicking while you sit and wait for the oil to heat up.
Why would a DPE care about the Hobbs when he charges per check ride, not by the hour?
 
It's never wrong to wait till everything is in the green....before pouring the coals. ;)
 
If people in climates that are actually cold waited for the oil temperature to be in the green, some guys would have to wait for hours, if it ever warmed enough. Despite having requirements on where the oil temperature is supposed to be measured, some airframes/engines really will never indicate any heat in the oil until a significant load is placed on it. Others will indicate warmer oil in short order.

As others have already posted, a reasonable warm up time while taxiing is likely enough to get the engine to accept throttle input and make full power without being reluctant. That is good enough for me.

I actually get more concerned about long ground runs. These engines are cooled by air flow through the cowl/engine compartment and the longer you sit on the ground the less airflow is getting to the engine to keep it cool. A compromise needs to be made; allow enough time for adequate warmup but I would avoid sitting on the ground too long so the engine doesn’t overheat.
 
i try to keep RPM below 1200 until i see green on the oil temp gauge on the engine monitor which is set at 90 degrees. thats not a problem in summer and not even a problem in winter if you plan ahead
 
I was told that even 60F is good enough.
 
I wait for the temp needle to move because the low end of the scale is 60F
 
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