High oil temp

[Dennis Blankenbaker]

I have been working on an O-320 that has had a high oil temp (red line high) problem for years. changed cooler, modified cowling. new oil pump for AD, temporarily installed a second oil cooler, changed the vernatherm 3 times, pulled out lots of hair and finally got it cured.
The oil screen housing that holds the vernatherm was not holding the vern. in the center of the hole in the case, just so slightly off center.
the vern. had a ware mark all the way around the tip but was not sealing the bypass. changed the housing and it cools just like it should.
can see no sign of damage to the old part at all, looks like it was made that way.

[Fortysix12]

I have been an advacate of thorughly inspecting this area first. Many threads of the very subject and I think it is the main cause of oil temp problems. However, very few have performed the inspection that you did to find the problem. Nothing like running cool.

[fobjob]

What's an O-320 doing with a vernitherm?

[Fortysix12]

You know I think I know the answer but I am going to ask Lycoming there perspective.

[S2D]

What's an O-320 doing with a vernitherm?

lots of 0320's run them. Just not the Super Cub

[Tom Jones]

I have an O-320 A1B I'm installing that came back from a Lycoming reman with a vernitherm and new screen housing installed. The old screen housing (that wouldn't accept the vernitherm) came back with "Do Not Install" written on it by the factory. The reman was ten years ago, so it's not a new policy.

Why wouldn't you want a vernitherm? All it does is make sure the oil is warm before it allows it to go to the cooler, right?. I don't run my car without a thermostat either!

[S2D]

Why wouldn't you want a vernitherm?

Didn't mean you couldn't or shouldn't, just meant they didn't come that way. Major alteration????

[ZKBPM]

I have a 320 engine that has done about 40 hours since a rebuild. The oil temp is about 230 and went into the red during enroute climb. I had the oil cooler cleaned out but the problem is only marginally better. I also replaced the vernitherm. The oil cooler is only luke warm to touch even after a long flight. It suggests to me that there is no oil flowing through it.
I am at a loss as to what to do next.

[Fortysix12]

Check the vernatherm in a pot of boing water installed in the housing. My bet is you got a bad vernatherm. That's what happened to me.

[Steve Pierce]

You can also replace the Vernitherm with the ball and spring that is called out in the parts catalog. Inexpensive and they work fine for me.

[750XL]

does the 0-290D have a vernatherm? I`m getting red line temps today for the first time but I`m on floats and it was 90 deg all day

[jcrowles]

[quote="750XL"]does the 0-290D have a vernatherm? I`m getting red line temps today for the first time but I`m on floats and it was 90 deg all day[/qu
ote] I have a pa-20 with a 0-290 that ran hot for more than 30 years. I don't know how many thousand dollars I spent at different shops to cool it down. It doesn't have a vernatherm. They put an outside air scoop on the cooler, didn't help! One shop said run it , as long as you have 40 pounds oil pressure its O.K. On a long x-country if the outside temp was 80 degrees it would red line all day! That makes you pretty nervous!! Finally I got mad, and went after the problem myself. First ,I made sure the baffeling was tight with NO air leaks ,particularly at the back top of the engine, Next I took the little original oil cooler off and installed a cooler like on a C-172 behind the left rear cly. as you face the cockpit in front of the plane. Now the temps run about 190 - 200 degrees! The Piper Short Wing club has an approval for this mod. I had it approved on a 337 form. jcrowles

[fobjob]

An oil cooler shroud matching to the cowl opening was good for 20-25F in my case. One of the few cooling mods that worked for me....

[750XL]

my oil cooler is mounted in front of the left front cyl. I have a big opening in the cowling for the original one. Should I block it off to get more air over the cylenders?

[fobjob]

In a word: YES...