O-200 Oil Temp Red Line

[6478]

The oil temp gauge red line on our O-200 equipped 140 is marked at 225 deg, which I always assumed was correct. I did a little digging though, and per the Continental TCDS for the O-200 the red line can actually be 240 deg as long as detergent oil is being used. I suspect the temp gauge was never updated after the O-200 was installed. Is 240 the red line that most folks with O-200s are using? It's been a real struggle to stay under 225 when it gets hot out here in Phoenix, so finding out that it's actually 240 would be a welcome change.

Thanks!

[8424]

Hi Dean!

My STC from Randy Thompson shows this:

Installation Instructions (STC SA547EA)

6. Remark the engine instruments to the following limits:
Oil Temp 225 degree F. Red Line

The STC that's in your aircraft paperwork should have the correct instrument markings information.

The 225 degree red line is the same on the oil temperature gauge in the C150D that my engine came out of.

Hope this helps.

Steve H

[6597]

The old 0-200 STC on my bird has a similar requirement for 225F

Lucas Emmett 0-200 stc.jpg (147.68 KiB) Viewed 3616 times

That being said the TC does have a notation for the higher temp. I believe the STC rules....

[6478]

Steve and David, thanks to you both. I hadn't considered checking the O-200 STC, but I will. The 225 red line on my temp gauge now makes sense assuming that's the case.
And to Steve, by coincidence all this started for me when I noticed my friend's C-150 had its original Cessna oil temp gauge that was red lined at 240. I guess 225 is too hot, except when it's not...