Engine warm up for first load on a Cessna

[cgypilot]

There seems to be different opinions regarding the amount of time a cold engine should be warmed up on a cold morning, before taking full power for take off.  One school of thought suggests that there is less wear on the engine if full power is applied very soon after start to warm up the engine as soon as possible.  An opposing opinion is to run the engine just above the idle for some time before even doing the pre take off checks.

What would be the consesus of the diver drivers?

Leon Pelser

[Mark Lamberson]

I have never heard of the full power to warm up the engine. I think I would seriously question whoever said that.

The purpose of low power warming up the engine is to get the viscosity of the oil so that it will move through the system to lubricate the vital parts. Full power before the oil will travel through the engine will reduce its life exponentially. I know people do it in their cars but the ramifications arent quite so bad, we cant just pull off the road. I admit that it seems like forever waiting for the temp guage to get moving on cold days but I believe it is worth it.

Mark Lamberson

[Chris Schindler]

I totally agree with Mark.  And to add:

I have also seen people start up a 182 at the hanger and quickly taxi it to the fuel pumps and then shut it down.  One mechanic I know about had a fit.  He said that in his opinion all that had been done there was that the protective oil left over from the last shutdown had been washed away with the start and that the cold oil had not enough time to really start flowing.  His opinion was that on the next start it would be even harder on the engine than the first.

Sounded pretty resonable but I don't know how true it was.  I just always tried to plan my fuel so that this scenario did not happen.  Or, I got my buddies to push me to the fuel pumps to get fuel rather than starting.  Orrrr... I went and let it warm up normal.  I waited until the oil temp was in the green and then went to the fuel pump, shut down, and fueled.  While I fueled the jumpers loaded up and away we went with a full runup before takeoff.  It meant less time for the jumpers waiting to go and less likely one of them would say "hey, can we get going here?"

Chris Schindler
D-19012
ATP

[akpilot]

Continental recommends that the oil temp be up to 100F before bringing the power up.

I fly 206s.  One of the airplanes I fly just went over 10000 hours, 8000 of that hauling jumpers.  The engines go TBO or beyond and we're not doing "tops" or replacing cylinders.  Our start goes like this:

Start with care to avoid RPM exceeding 1000, then 800-1000 RPM for about 1 minute before increasing RPM to 1100-1200 for warmup.  We consider the engine warm when CHT is in the green AND there has been a slight drop in oil PRESSURE from the pressure noted at startup.  Taxi to loading area, quick mag and prop check done while back taxiing for takeoff.  Gradual application of power for takeoff.

I've been flying these airplanes since '96 and there have been no engine maintenance problem relating to cylinders/valves/etc.

[Andras Arday]

What I do on the 182 is the following:

- I start the engine 15-20 minutes before the first takeoff and let it run on idle for 3-4 minutes, then stopping the engine. When later I start it again the oil is in the green immediately.
- I never increase the RPM above 1.000 untill the CHT is below 200°F. (I have digital CHT)
- Never taking off until the CHT is below 300 °F

[flaming_moe]

I fly the 206 with similar warm up procedures to Andras..
 -600 RPM until oil pressure rises inti the green
 -1000 RPM until 200 CHT
 -1200 RPM thereafter until 260 CHT is attained   for the run up.
 -Cowl flaps open during the whole warm and run up

[FowldPlug]

Just curious, why wouldn't you want to make use of the cowl flaps in helping to warm things up?

Thanks.

[averettpilot]

I live in Arizona so the oil is always warm 

[skysurfer2010]

I have to agree with Mark and Chris. I'm also surprised nobody mentioned a preheater. Whenever temps were below 32F the previous night I'd preheat it for 15 to 30 mins.

[PilotBB]

"One school of thought suggests that there is less wear on the engine if full power is applied very soon after start to warm up the engine as soon as possible"

you will certainly make your mechanics happy with those high rpm starts.

we get the oil temp in the green before take off especially when flying turbo charged, so just do a normal runnup in the morning and that should do it. if its a cold winter then run at 1000 RPM or less for a few minutes then mabey go up to 1200 for a few min before doing your standard runnup.

[Dash 2]

  On the C-180s and 182s we use 1000rpms or less until CHT is 200*. In the winter we plug in the oil pan heater.
  On the Beaver the oil temp had a minimum level before flight. By the time the oil was there CHT was plenty high. There was an oil heater on it as well. Our Cessna engines would normally make 2200 to 2300 hours with a top around TBO. The Beaver had to be overhauled at 1500hrs because of an AD.

   -2

[Gliderboy]

"Just curious, why wouldn't you want to make use of the cowl flaps in helping to warm things up?"

This is a no-no for round engines, and I expect that it applies to the 182 as well. Probably because with the cowl flaps closed there is very uneven and very little airflow over the cylinders, allowing some spots to get hot while others stay cool. Best to talk with an authority before trying this.

As a mechanic, the techniques mentioned above sound very sensible to me (no full throttle when cold, though!).

[PilotBB]

i've been asked why not close the cowl flaps as a way to help warm things up a bit, and i really dont have a reason why not too other than i've never done it, nor ever been told to do it. another idea is too pull the prop back enough to let the oil cycle through the entire system and therefore allowing for a more rapid oil heating. any thoughts?

again usually after a normal runnup i'm in the green, but then again i'm at a sunny california dz.

hey i like the aviation is a trap door comment....