Oil Temp - M20E

[aeromancfi]

I had high temp problem in my 1965 M20E that was traced to a poor connector on the firewall where the temp bulb lead connects to the wires from the gage.  Replaced the forward wire and connectors and Presto!! -- normal oil temp.   However, on hot days at altitude I sometimes have to 1. richen the mixture a bit or 2. crack open the cowl flaps.  This takes care of it.  Dan S

[M20E-1964]

Well, the oil cooler went out for a rebuilt and we noticed the cowl baffling (rubber stuff that forms seal) was ripped.  Hoping that by fixing those two items it makes a difference.

[rahawk]

I recently installed an edm700, with fuel flow, oil temp and oil pressure.  Factory gauge generally read 180-190 temp, while the edm shows 15-20 degrees hotter.  The factory sensor is close to the oil return line from the oil cooler, while the edm is installed on the front of the case.  My mechanic and I reasoned the the diff is a result of the locations.  I have found, as others have indicated in this thread, that running with cowl flaps 1/2 has a significant cooling effect on temps.  On hot days, running lop and with cowl flaps 1/2 open, I see oil temps of 205-210.  I'm happy with this....

 

[maxfly]

I have a problem with the oil temp and CHT gauges. Oil temp sometimes works, sometimes doesn't. When I turn power on, both gauge needles dive to the left.  When I disconnect the sender for the oil temp, it does the same thing. When I ground the sending units lead (off of the sending unit), it deflects all the way to the right. 

Cyl. head gauge does the same thing but when hooked up, it's dead all the time. Both the sending units show resistance.

Whats up and what to check next?

[maxfly]

 Sorry, same post

[Alan Fox]

Peoples !!!!!!  Green is not hot .... The red is hot...... Its either in the red , or in the green......Don't overthink it.......You want oil temps at least in the 200 range , If it doesnt get hot enough to turn the condensation in the case to steam... The condensation in the case mixes with exhaust gases , and turns to acid.........Think about it.....

[MB65E]

On the 65e's how many folks have the plate behind the stock cooler location? Flew ours yesterday after overhaul. On Departure ambient was 104* and yes the oil temp was high. Just trying to get it down to brake in the engine at high power settings. Second flight used no oil. Our plate was MIA if it ever had one. I've seen the plate on others but they were later models. Drawing or pic available?? Cylinders were great with temp! Fun project!

Thanks!

Matt

[oldn0tded]

My experience with my '75 F model shows oil quantity plays a role as well. My oil temp is higher when running 6+ quarts as opposed to a full 7. It's basic physics, more oil equals more capacity to absorb and dissipate heat. I try to always have a full 7 quarts in mine and climb at 110.

[Marauder]

My experience with my '75 F model shows oil quantity plays a role as well. My oil temp is higher when running 6+ quarts as opposed to a full 7. It's basic physics, more oil equals more capacity to absorb and dissipate heat. I try to always have a full 7 quarts in mine and climb at 110.

Another 1975 F owner! I agree as well on the volume of oil. I typically run 6 and it is hotter than when I have 7 in it. Do you have a digital value for your oil temp? Like from an engine monitor? Just curious to see where your temps compare to mine.

[rbridges]

Another 1975 F owner! I agree as well on the volume of oil. I typically run 6 and it is hotter than when I have 7 in it. Do you have a digital value for your oil temp? Like from an engine monitor? Just curious to see where your temps compare to mine.

 

makes sense, but my engine seems to lose oil quicker when I have more than 6 qts.  It settles down and holds at 6.

[rbridges]

Mine does, too.  But I start with seven quarts plus 5% Camguard anyway and add a quart when it gets down to 6.  Oil is cheap and I have to clean the belly every few months regardless.

 

Jim 

 

so you're basically starting at 8 and let it work its way down to 6?

[jetdriven]

See, those pre-95 engines are good solid stock.

So was that fuel divider and oil pressure gauge hose. Jim about took a shit when I read him the data tag on them.  1977 ! Yikes!

[N601RX]

I still had some of the original hoses from 67 behind my panel last year until I replaced them.   Hard as a rock.

[MB65E]

So does the plate behind the cooler help lower temp? I think the best bet will be early am or in the Evening. It's not in any IPC from what I can tell.

-Matt

[jetdriven]

Yep!  And it's not just the years.  My airframe has over 10,000 hours on it and two of the three hoses that you recommended that I replace, Byron, were original.  The third was dated 1980 so it probably only had 7 or 8, 000 hours on it.  Those were Top Gun maintained hours, by the way. 

 

Now the hoses are all shiny and new, though, and the new PHT, Inc. integrally firesleeved hoses are way higher quality than was the original stuff.  Should be good now for another 10,000 hours or so. 

 

Jim

I do it like Johnny Cash, one piece at a time.

[oldn0tded]

Another 1975 F owner! I agree as well on the volume of oil. I typically run 6 and it is hotter than when I have 7 in it. Do you have a digital value for your oil temp? Like from an engine monitor? Just curious to see where your temps compare to mine.

No, I don't have an engine monitor, want one, just haven't done it yet. I realize this is weak, but I rarely see my gauge past the midpoint of the scale. The oil temp has never gotten to the point of raising alarms. So, I don't have a number, sorry. However, from the trend indicated on the forum, I suspect my gauge might be off. Just another reason for an engine monitor. FWIW, the CHT runs really cool too. Never approaches the redline.....provided I climb at 110-120.

As for oil consumption, I go through a case of oil in a forty hour oil change interval. At the change it uses 7.5 (allowing for filter "fill"), then in the ensuing 40 hours I will use the other 4.5 quarts. I may be "pumping" some overboard, there is some oil on the belly. Not enough to make me change what I'm doing.

BTW, Love the plane!!

[Marauder]

Another 1975 F owner! I agree as well on the volume of oil. I typically run 6 and it is hotter than when I have 7 in it. Do you have a digital value for your oil temp? Like from an engine monitor? Just curious to see where your temps compare to mine.No, I don't have an engine monitor, want one, just haven't done it yet. I realize this is weak, but I rarely see my gauge past the midpoint of the scale. The oil temp has never gotten to the point of raising alarms. So, I don't have a number, sorry. However, from the trend indicated on the forum, I suspect my gauge might be off. Just another reason for an engine monitor. FWIW, the CHT runs really cool too. Never approaches the redline.....provided I climb at 110-120.As for oil consumption, I go through a case of oil in a forty hour oil change interval. At the change it uses 7.5 (allowing for filter "fill"), then in the ensuing 40 hours I will use the other 4.5 quarts. I may be "pumping" some overboard, there is some oil on the belly. Not enough to make me change what I'm doing.BTW, Love the plane!!

My JPI 830 is a new addition to my plane. I ran for years with an Insight GEM 602 that was great for monitoring cylinder/EGT temps and for leaning. Now with the additional parameters, I am getting the complete picture. Interesting, my gauge runs in the middle of the gauge as well. After reading Bob Belville's comments on his oil temps, I watched mine on my last flight. Although the gauge stayed mid range, my oil temp was over 200 degrees according to the JPI sensor. I will plot this out and post a copy of it compared to outside air temp. It was eye opening for me. I always thought I was in the 180 range, no so.

[jetdriven]

I think Mooneys read the oil temp after the cooler.

[Marauder]

BTW -- I agree, the F model is great! The 1975 is relatively AD free and has many of the early J options -- just not the speed mods.

[oldn0tded]

My JPI 830 is a new addition to my plane. I ran for years with an Insight GEM 602 that was great for monitoring cylinder/EGT temps and for leaning. Now with the additional parameters, I am getting the complete picture. Interesting, my gauge runs in the middle of the gauge as well. After reading Bob Belville's comments on his oil temps, I watched mine on my last flight. Although the gauge stayed mid range, my oil temp was over 200 degrees according to the JPI sensor. I will plot this out and post a copy of it compared to outside air temp. It was eye opening for me. I always thought I was in the 180 range, no so.

Thanks, your experience confirms my suspicion. My prior experience with other engines (internal combustion types) has taught me that oil temps around 200-220 are beneficial from the standpoint of driving the moisture out of the oil. Generally speaking, oils don't start breaking down until over 260, and synthetics are considerably better than that.  So, now I know, anything much over the middle is too hot. Thanks again.

 

Having said that, I still have an engine monitor on my list of things to do.......right after the tank reseal.