Our club has a Cessna 182P that runs hot. We have a cylinder head temperature monitoring system and we have to run it almost full-rich to keep the cylinder heads under 400 degrees most of the time.
Our home base is in Colorado at ~4500 MSL, so generally airplanes need to lean a little even on the ground and most certainly after we're airborne and running in the 9000-12000 ft range. We've had it looked at many times and the mechanics don't seem to find anything wrong.
We can only find one thing that seems different from our other aircraft (172s and PA-28). The cowl seal on the 182 that is attached to the engine baffle doesn't quite reach the cowl on either side. In fact there's about a 1" gap. On the other three the cowl contacts with a little compression on the seal. They seem to be set up to limit any air from bypassing the engine.
So….I'm curious to know from other C-182 owners whether the cowl baffle seal on your plane contacts the cowl on the sides. When we look on either side of the prop and into the nose of our 182 on either side of the engine baffle, or feel where the rubber gasket is, we are wondering if it should be in full contact with the cowl and the seal is the wrong size.
Thanks in advance for your help
I own a 1972 182P that has had some cooling issues. Last year I told my mechanic to check the intercylinder baffles as my cylinder #3 always was running too hot. I try to maintain my CHT at 380 degrees or less and it would climb over 400 at the drop of a hat. He found a badly damaged and warped baffle which we replaced. That did bring down the temperature of cylinder #3 quite a lot. Now I have one engine side where all the cylinders tend to run warmer than the other. My flexible baffles attached to the metal structures are in sad shape, likely original, and they are next to be replaced as I am sure they are letting cooling air escape out the back rather than it being forced down between the cylinders. This sounds like the situation you may have. But there may be more than one baffling area that needs attention. To me it's much like a whack-a-mole game… close off one air leak and you will find the next! Be sure you check the whole baffling system and not just those cowl seals.
Thanks for confirming our suspicion David! We are planning to re-do the baffles at our next 100 hr. inspection.
Absolutely there should be no "gap in the seal"!!!
Think of how the engine is supposed to be cooled... air comes in the nose by the propeller. This is called the "high pressure deck". The air then flows around the cylinder fins to the "low pressure deck", taking engine heat with it. If the cowling is not sealed, there is no (or very little) air pressure difference and hence a lower air flow. The oil cooler works in a similar way.
Have a mechanic look it (Terry and Larry at Professional Aircraft Services at KFNL), or stop and talk to any other 182 owner who happens to have their hangar door open. :-)
Jer/ Eberhard, KFNL. Not a mechanic, but previously owned a C182 and C206 at KFNL.
Thanks Jer - We're taking it to our guy at KLMO later this week. I will discuss with our club's board about having Terry and Larry at KNFL look at it if he's uncertain / unable to correct it.