Went with friend the other day in 1967 0-300 powered 172 --- oil temp was bumping red line most of the time .Need to get it cooler ASAP -- any suggestions .Thanks Bill

182 STOL driver wrote:Went with friend the other day in 1967 0-300 powered 172 --- oil temp was bumping red line most of the time .Need to get it cooler ASAP -- any suggestions .Thanks Bill

What are in the logs from the last engine inspection? I would start there...

Aside from the regular stuff I'd check out Steve's Aircraft Oil Cooler.

What was the outside temp? If it was a hot day it's not uncommon to see the oil temp up near the red line. I've seen my temp (C-145) get up to about 210-215 during a long climb when it was 95 degrees on the ground. I've heard Contenental actually changed the redline on these engines to 240 degrees, although all of the temp gauges are marked at 225 for the red line. If the plane has a spin on oil cooler their are clamp on fins that cool the oil a bit. I know a guy with a 172 that put one of those on his filter and it did help. You can find them on the aircraft spruce site. Before you go spending any money check the accuracy of the guage first.

182 STOL driver wrote:Went with friend the other day in 1967 0-300 powered 172 --- oil temp was bumping red line most of the time .Need to get it cooler ASAP -- any suggestions .Thanks Bill

I had an o-320 powered 172 that had the same problem.

Continental makes a bolt on cooler. I have seen a few on ebay over the years.

I never did find one while I still had the plane.

Another thought.
Maybe the gauge is not calibrated???

The O-300 is notorious for a high oil temp indication and cessna put a cooling blast tube directed at the oil screen/temp prop housing to remedy that problem. That is not to say this particular engine in your friends airplane is not having some other issues but I would first start by looking at the baffling, blast tube and other oil temp indicator components before investing in an after market cooler. There is a lot of good discussion on this issue over on the 170 website. My 2 cents worth

I have flown 0300 & O320 172's in the tropics for years and the only time the oil was > 200F was because of other issues. Mostly mechanics signing off bad engines.

Check your baffling and also check cylinders for blow by, Hot gases getting blown into the crankcase will heat up that oil. 190- 200° is not uncommon on days like now. On a hot day in the 170 I used to have I would see anywhere from 200 to 230°.

If you read the C170 Assn's books or website, there's lots of talk about this high oil temp thing and how to cure it. I owned a 300-powered C170 for years and high oil temp readings were the norm, even after a fresh engine overhaul. I tried re-aiming the blast tubes, messing with the baffling, adding a "seaplane lip" to the lower cowl, clamping a JC Whitney finned aluminum sleeve onto the spin-on filter, different oils, richer mixtures, etc. None of it did squat. One thing to keep in mind, the old stock gauge was redlined at 225 but per the TCDS #E-253 the oil temp limit was later revised to 240.

I did the exact same stuff is Hotrod 180 with the same results.

Good article on the matter:

http://www.avweb.com/news/maint/182617-1.html

There should be an opening ahead of the oil pan. I would make sure that it is unobstructed.

On an engine known to want to run on the hot side, and has no ol cooler, why wouldn't an oil cooler be the first attempt at getting the temps down??? Weight..... cost??

A $30 oil sample analysis would be a good investment to rule out something deep.

I flew a 170 with a C-145 for ten years and my oil ran cold if anything. This is the first I have heard of that powerplant installation having a reputation for high oil temps.

+1. My O-300B is also cold blooded. Even during summer months here in the vast desert wastelands of northern Nevada. I spend a lot of time climbing and cruise high RPM's, and that damn oil temp likes to live in the 170-180 range.

Gump

I'd have the timing checked, too. I've reported here a couple years ago that I was having overheat problems with the O-360 Lycoming in my P172D, notably the back 2 CHTs, which would often redline. But although the CHTs were my concern, the oil temp was always near the redline, too. My IA changed the baffles, and I spent an afternoon making sure there were no chips or other items interfering with air going through the cooling fins. When that didn't make a huge difference, I contacted Mike Busch, Internet IA guru, and he promptly got back to me, said that Lycoming had changed the timing recommendations on all but my particular model engine, but that's what he recommended--instead of 20 degrees BTDC, make it 10.

Well, my IA was concerned that I would lose power. If I did, I can't tell it. But the cooling issue really died down. The back 2 CHTs still run warmer, but not as hot as they were running, and the oil temp now runs right in the middle of the gauge, except on really warm days, when it will creep up about to the 2/3 mark.

Cary