High Oil Temp

[ErickR]

Lately, in level flight I've been getting oil tempature of 220+ degrees with slighly low pressure running 6 qts of oil and oat of 50 degrees or less. Just replaced the vernatherm valve and that hasn't had any effect. CHT temps seem to be fine at about 350. The oil cooler isn't obstructed and appears to be good.

What should my oil temp be? Anyone else experience this proplem?

 

[Mooney65E]

Had the same problem a few years ago. My oil cooler also appeared to be unobstructed from visual observation. My mechanic took the oil cooler off and soaked it in solvent overnight and blew it out. Oil temps now 190.

[HawgDriver]

New electronic monitor or factory setup?  Did it suddenly start doing that or has it slowly been rising each flight?  I only ask to see if it would be worth it to throw the oil temp probe into some boiling water to see what the gauge reads.  You're in Utah so it would only be what, 205 or so??? 

 

[Lood]

I used to have tha same problem on my F. During the last annual, the AME removed the oil cooler, had it ultrasonically cleaned and resprayed it with a heat conducting paint. They also did a superb job of insulating and properly routing the two oil lines running to and from the oil cooler. These were bare and are very close to the exhaust. I now see normal oil temps of 160 deg and during climbs and warm days it might max at 180 deg.

[ErickR]

It seems to have just started getting this high, I imagine the problem was masked by the colder temps of winter. We purchased the plane in January so this will be my first summer with her.

I am going to try a new oil temp sensor and see if that helps. If not we'll try cleaning the oil cooler.

Thanks for the help

[Jsavage3]

My '86 M20J just started devoping high oil temps -- the last three flights.  Oil quantity is good at 6 plus, the engine baffling is good, the oil cooler is clear of external debris and the belly is clean of oil.  It has been gradually worsening with each of the last three flights and I hope the vernatherm will fix the issue.  The guage is definitely functioning and I believe it to be accurate because when the temp goes up, the oil press goes down to just below the green arc when at idle.  The last flight it went from barely touching the bottom of the green arc at takeoff (OAT 35 degrees F, cowl flaps open, mixture rich and IAS 120 KIAS to 4500 feet MSL) to starting to touch the redline (about 240 degrees F and redline is 245 degrees F) once I reached 4500 feet four minutes later -- the oil temp indicator was moving quite fast.  I aborted the trip, reduced power and completed a decsending turn back towards the airport.  The temp peaked and decreased slightly once I started back.  My gut tells me oil system (guage, vernatherm or cooler) or internal engine issues -- I dearly hope it's not the latter...  Will report back once I have more info...  Wish me luck please.

[Skybrd]

Quote: Lood

I used to have tha same problem on my F. During the last annual, the AME removed the oil cooler, had it ultrasonically cleaned and resprayed it with a heat conducting paint. They also did a superb job of insulating and properly routing the two oil lines running to and from the oil cooler. These were bare and are very close to the exhaust. I now see normal oil temps of 160 deg and during climbs and warm days it might max at 180 deg.

[danb35]

Quote: Lood

I now see normal oil temps of 160 deg and during climbs and warm days it might max at 180 deg.

[KLRDMD]

[robert14]

I purchased my M20E about a year ago. I had 220 to 235 deg EDM700 oil temps (205 to 210 on the factory guage) on my M20E. Verified temp sensors, added new oil cooler and hoses,  addednew vernatherm, maintained 8 qts; none of these measures made any difference;. then I found Mooney SB M20-182 on Mooney's web site. I purchased the kit (M2-182-000) and had it overnighted for $240. It took my mechanic 6 hours to install. My oil temps now never go above above 205 deg (100+deg OAT). The kit also reduced my highest CHT temps (#2) 30 deg, from 410 deg down to 380 deg) on climbout. I highly recommend adding this kit to anyone with a M20 E or F and a factory cowl.   

[Jsavage3]

Turned out to be the vernatherm.  I landed with oil temps near redline on the factory guage, popped the cowl and the oil cooler felt cold to the touch.  That is when we felt fairly certain that we were on the right track -- vernatherm or blocked oil cooler.  With the new vernatherm, I now see 160-180 degrees on the factory guage.

[carusoam]

Jim,

Did you get a chance to see the old vernatherm?  Was there anything obviously wrong about it, bent, worn or anything?

Glad you found the smoking gun on this one.  It was sounding alot like something more serious.

Best regards,

-a-

[Lood]

Quote: Skybrd

 I was wondering if my oil cooler lines are routed correctly since they hit and restrict my left cowl flap. The oil temp runs about 200 degrees and I wish it were running a bit cooler. Did they re-route your cooler lines? I know about the mod to relocate the cooler to the back of the baffling but not sure if I want to do that. Is there a way to baffel the exhaust cooler to not restrict the Number 2 and 4 cylinder air flow. It would seem to me that some kind of baffling with a boot on the back of the oil cooler and large flexible duct to allow the exhaust to be a separate flow from the cylinder flow.

[Lood]

Quote: danb35

Maybe it's just me, but that sounds too cool--you want the oil temp to be at least 180 deg to boil out moisture that collects there.  Maybe your probe is in a cooler part of the oil path...

[Skybrd]

I fly in Bakersfield and Inyokern, Ca and the summer temps are hotter than the blazes. My M20E doesn't like the increased heat and causing higher oil temps and lower oil pressure. I was wondering if the heat from the muffler could be heating the oil sump since their real close. Is there suppose to be baffel between the muffler and the sump? Another area of concern is a insulated fuel line that might be restricting the cylinder airflow.? My cylinder head temps always show good with no overheating.

[tony]

Eric before you go replacing parts, might I suggest purchasing something like this:

http://www.harborfreight.com/non-contact-laser-thermometer-96451.html

Then after you land, you can pop the cowl off and see if the temps you are reading make sense.  You should be able to get a reading off the sump, the cylinder heads and the oil cooler.  At the same time you can check the baffle seal.  If the baffle seal isnt going forward, air can sneak past the engine and not be forced down through the fins.    I've also seen those stinkin muddobbers make a nest everywhere, not sure if you have them in utah.

[Shadrach]

Quote: ErickR

It seems to have just started getting this high, I imagine the problem was masked by the colder temps of winter. We purchased the plane in January so this will be my first summer with her.

I am going to try a new oil temp sensor and see if that helps. If not we'll try cleaning the oil cooler.

Thanks for the help

[alex]

Not completely off topic, but generally how long does it take for the oil temp to reach the green arc after turning on (for the first time of the day). It seems that my J, even when outside temp is in the 80's, takes a long time to warm up.

[Shadrach]

My POH says anything >100 for take off is kosher... It's usually there when I reach the runway except in the dead of winter... I'm in the 135ish after a 2 min taxi this time of year.