High Oil Temp?

[Joseph II]

I recently flew a Cessna 172 (a 1975 year model I believe). The outside temp was 32-34°C and the field elevation was 5800' MSL.

The preflight went normal and takeoff was uneventful. When we got about 5 miles from the airport I noticed the oil temp was just below the red line but above the green (in the black) which was the tiny space on the gauge between the green and the redline. We enrichened the mixture and leveled off from our climb but the temp did not drop but rather rose a bit to just barely below that red line.

We returned to the airport and landed, when I went in to request a different airplane, the front-desk said "We've spoken with Cessna, and they said that on a hot day like this, as long as the oil pressure is normal (which it was), then the oil temp can be sitting at such a high value."

The next plane I flew had the oil temp in the green the entire flight (although I have to say it was towards the top of the near the upper 3/4 of the green the entire time).

Do you think I made the right decision, or do you think this is normal for a hot day like it was and I should have kept fying the airplane?

Thanks

 

[FSB99]

if you don't think it's all kosher, then it's not. good decision bringing it back. However, you have to also look at the big picture of things, i.e., if the oil pressure was also very low, out of the lower end of the green range, then you could have a problem. if the oil pressure was in the normal range, maybe even lower than normal, but still in normal parameters, then just keep an eye on the temp, everything should be okay.
i had a student who owned his own airplane, and this particular airplane scared me the first few times we flew it.. the oil temp ran very very hot, and the oil pressure, when the engine warmed up, ran very low.. but, both gauges still always indicated green, just at the limits.. despite having various mechanics look at it, and get their opinions, everything always worked out good. just the way that engine operated.
another thing to remember, if there's 'too much' oil in the plane, the pressure can run high. at the flight school i worked at, we had a problem of folks adding a quart of oil when they noticed it was one quart lower than the max, during preflight.. they didn't think about the fact that the airplane had JUST come back in, engine was still warm, and the motor wasn't done draining its oil back into the pan, thus giving the indication that it was slightly low.. so in essence, they had an extra quart in the sump. and yes, the oil temps tended to run high in that condition.

 

[HAZ-MAT]

I think that bringing it back if alls not good is a smart decision too. Its that ego in us that says alls well, and continue the flight, but who know's if something is going to happen...
My 2 cents also is sometimes instrument needles stick in the hot temps.. i've had that happen a few times flying senneca's, sometimes a tap will fix it, or sometimes Mx needs to fix it.

 

[generaltso]

I think for your level of experience you made a good decision. As you get more experience, you will realize that most gauges in your typical GA trainer are worthless.

 

[Jet_Dreamer]

i have seen very similar gauge readings on many cessna aircraft. 172's, rg's, 182's, 310's 340's, almost all. this time of year when its warm at altitude you will see warmer oil temps. i have questioned this many time with mx. as long as its in the green and you have good oil pressure you will be ok.

 

[KnowledgeSeeker]

I think you made a very good decision because you are not familiar with that aircraft. If you had flown it for years and it always indicated high then mabey it's ok. but if it is always in the middle of the green and then starts going to the top- coming back is wise.

I flew a C206 that always had both needles in the center which later started showing high oil temp, but the oil pressure was perfect. We also had a Graphic Engine Monitor for each cylinder that showed nothing abnormal. When we opened the oil pan after that flight there were 3 inch long metal shavings from a broken bearing. I agree that GA gages are mostly inacurate, but sometimes they can really save your hide to trust them when they are telling you bad things!

 

[jetdriven]

right on to the man who says the factory guages are worthless. How about those integrated 6-in-1 guages seen on bonanza's and mooneys?? The needles are all over the place, and if you tap tyhem they all change.

If the oil is too full it will blow out the breather tube, thats it.

It might run oil temp hotter than normal because it was too lean or the guage is off.

Most turbocharged 210's and Be-36TC's oil temperatures run less than a needle's width from the red line on oil temp. This is still considered normal.

 

[blott]

I'm impressed someone looked at the guages...


If you are posting here AFTER after something happened-then you did the right thing....


B

 

[de727ups]

Lake Mead Air

used to run 172's out of Boulder City, NV in the summer. I noticed the high oil temps but good pressures coming out of the canyon. Was told that if the pressure was okay that you didn't need to worry about the temps....that was in 1985.

 

[metrodriver]

High oil temps in cessna's is quite normal in the summertime. You might want to take a look at the baffling since that 's what directs the air through the cooling fins to the bottom of the engine. If the baffling is bad the air will not flow over and between the cilinders and your oil temp will go very high, since the oil is now the only cooling medium. Also sacrifising a little climb for airspeed will improve cooling, but I also realize that with temps that high at that altitude your climb performance in a 172 will be hardly worth talking about