High oil temperature/low pressure

[xavierde]

So I’ve had this in flight today (25”/2500). Noticed this 10mins after departure then tried to throttle back to 23” and open the cowl flaps. Helped a bit the oil temp but the pressure stayed low. Oil change was last week and I only flew a 15mins trip since so that must come from that but I can’t figure out what the problem is.

 

Edited February 15, 2020 by xavierde

[hammdo]

Did you ck the oil to make sure you had the minimum required? Air cooled engines use oil to help cool. Just to eliminate that first since you stated oil was just changed...

 

-Don

[xavierde]

Yes, I was at 6.5qts. Was at 5qts upon landing...

[hammdo]

Top it off to @ least 7 and do a run up to verify no leaks and you don’t see a lot of smoke from the exhaust. 1.5 quarts after a short flight would concern me for sure. I’d speak with the mechanic on that much of a loss...

you didn’t say what type of Mooney - or if it was turbo charged.  That may also help to know...

-Don

[xavierde]

M20K. I’m wondering if the quick drain could be the problem as I can see traces of oil on the nose gear door so coming from the cowl flaps and the filter looks clean.

[larryb]

It takes several days for the oil to drain back into the sump. So checking level immediately after flight will show a quart lower than the reading just before the flight. High oil temperature will lead to lower pressure due to the oil thinning.

That said I do think there is a problem. I’d start with the high temp reading.

[jlunseth]

I had to make an epic emergency landing due to a quick drain, so yes, check the quick drain, but I don’t think that is your problem. The quick drain is at the bottom of the pan and all it does is allow the oil to be drained out.  Even if the drain is failing, as long as you have sufficient oil in the sump and the system is otherwise working (screen is not plugged, pump is good, etc.), a failure of the drain is not going to cause what you saw.  The problem a drain failure causes, is allowing all your oil out until it no longer gets picked up by the intake in the sump.  Then you will see low or no oil pressure.  If you had 5 qts. in the engine, that is not the cause.

A drop from 6.5 to 5 qts. might or might not alarm me.  If the plane had sat for more than a day, then the oil all drains into the sump. When you preflight and read the oil stick, then fly, about a quart of that gets redistributed through the engine, so 6.5 before flight might be 5 after flight.  It is, though, a little much.  The “loss” should be about a quart from before to after flight.

From the looks of the nose gear door and the shiny spots I see in your engine pictures, it appears there is a leak of some kind.  Have to trace it.  They are not easy to find because the oil blows around inside the cowling in flight.  

What was the OAT?

[xavierde]

31 minutes ago, jlunseth said:

What was the OAT?

-10 C

[xavierde]

We changed the oil last week so I’m suspecting something related to that. Has anyone had a bad oil filter before? 
 

Thanks for all the advice, I’m worried flying back home without sorting this out properly.

[Skates97]

36 minutes ago, jlunseth said:

 

From the looks of the nose gear door and the shiny spots I see in your engine pictures, it appears there is a leak of some kind.  Have to trace it.  They are not easy to find because the oil blows around inside the cowling in flight.  

When we were chasing an oil leak on my plane my AP/IA put fluorescent dye in and had me fly around the pattern only once. He didn't want me flying any more than that because it would just blow the oil everywhere. Shut down the plane pulled the cowl cheeks and put a black light on it. The leak was easy to locate at that point. 

[jlunseth]

Its possible the air/oil separator froze up.  Water is made during the combustion process.  The engine creates pressure in the crankcase and oil pan during operation, and the engine releases that pressure through the breather hose.  The breather usually routes through an air-oil separator that causes the incoming air/oil mix to spin, which takes the oil out.  The air then passes out the breather tube and the oil returns to the engine.  This is normal.  But at cold temperatures, the moisture can collect and freeze in the can (the separator), blocking the exit.  The engine builds up pressure and pushes oil out of any available exit.  It happened to me at 12 F, which is the range of your OAT (14F).  The cure is to simply take your time on the tarmac after start-up, to allow the engine to warm the engine compartment, which warms the separator.  I have been in the minus 50’s F at altitude and not had the problem. Taking off too soon on after start-up on a cold day will cause it.  Same symptoms you saw, low OP high temp. It is a benign issue though, get the plane in a heated hangar to thaw the can, refill, clean up any mess, and give the engine compartment time to warm up next time.

The separator is worth checking, but your photos are showing liquid oil and I don’t think the separator is the problem.  It looks like a leak of some kind to me.  When my air oil separator froze I got misted oil, gray streaks, about a foot and a half wide down the sides of the aircraft, not the liquid oil you are seeing.

PS you are right to be concerned.  High temp and low pressure signal a serious issue such as a blown seal or dying oil pump. Get it fixed before you fly anywhere.

Edited February 15, 2020 by jlunseth

[N231BN]

If you still had 5 qts your temp/pressure issue isn't from oil level. You most likely had your oil cooler congeal. What oil are you running?

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[carusoam]

Reviewing where we are at so far...

1) Moisture frozen in a line can be a hazard... and easily solved by getting it melted... put it indoors over night... see if the problem goes away...  then figure out a way to keep it from happening again... JL gave some good experience...

2) oil Temp challenges often come with the oil cooler not working properly... there is a temperature control valve that has the oil bypass the cooler/radiator... the valve is called a vernatherm...

If the vernatherm keeps the oil from going to the oil cooler... the oil will get pretty hot...

3) get an IR thermometer...point it at the oil cooler... if it isn’t hot the oil isn’t flowing through it very well...

4) When was the last time the oil cooler got flushed...? They get filled with gunk and block the flow like the vernatherm being stuck...

5) Cold weather can exaggerate how bad the gunk can really be...

6) Use the IR thermometer to see if there are cold spots or hot spots indicating what oil lines are blocked in the cooler... gravity ensures certain tubes to get filled up first...

7) The engine has a couple of ways to protect itself, but not for very long....

8) review cold weather ops for your plane... many Mooneys have a method of partially blocking the oil cooler to cut the surface area in about half...  it is quite possible the oil cooler has over cooled the oil as it got into the cooler and gelled up pretty well to block the flow of oil...

9) If your POH doesn’t have a reference for blocking the oil cooler for cold operations...there are threads around here for that...  expect your engine manufacturer has some data to share as well...

10) Ovations have a piece of sheet metal that slides in place for cold weather ops... NJ doesn’t typically qualify for cold weather ops...

11) What oil viscosity are you using in winter?  This might be an issue as well.

12) think normal psychology first, then abnormal stuff next...

13) Vernatherm function is pretty easy to test... a pot of heated water works... and a thermometer... 

14) we are experiencing some of the coldest temps of the year in NJ, today... 10°F on the ground.  Preheating on the ground is required to get most engines started... making ice in most lines not much of a challenge at the starting point... (did you use pre-heat? Was the plane above freezing in the hangar?)

15) low oil pressure, and high oil temps... are stating the oil cooler isn’t working correctly... now... figure out what is doing the blocking... the vernatherm is no longer in control of the oil flow... either a bad vernatherm, or a blockage in the cooler, too much surface area, or too thick of an oil choice... or ice in the system...? (That too...)

PP thoughts only, not a mechanic...

How is that for ordinary PP knowledge? All stuff I read about on MS....

Best regards,

-a-

[xavierde]

Thank you everyone.

I went to the airport tonight, added 2qts and ran the engine for 20mins (10 at 1000rpm then à run up at 1500 and 2000rpm and back to idle for 5mins for the turbo). All Ts & Ps look normal but I still wonder how I lost 1.5qts of oil during that previous flight. 
 

 

[MarkD34M]

Have you checked the turbo carefully? 

[carusoam]

Let’s think about what happens while oil is in the extra hot mode...

OK, enough looking backwards...

Lets’s look forward to making sure we identified what is going on, and it’s not happening again...

Know what the one temperature reading we got to see, doesn’t represent all of the oil all of the time...

When it gets outside of the normal operations... this one point, doesn’t make anyone comfortable...

We are only comfortable with that one point of data because all the other engines said it worked well with that one point...

Now we are in the experimental category, with only one point of data... to go on...

 

Get back in the normal category, and that one point of data is much more meaningful...

So far so go good, run up looks like you are ready for the next step... as far as a PP thought process goes...

What is next?

Did you look up...

• oil type/grade
• oil cooler block...  that closed off portion...
• IR Temp measure of the cooler... any sludge causing problems...
• Flushing the oil cooler... the cleaning method...
• Anything regarding a vernatherm...?

Or are you feeling... lucky?  

Going to fly without a hint of what actually caused your very real instrument challenge?

Make it a short flight... in case they show up again...

PP thoughts only, not a mechanic...

There are so many preventative maintenance steps a PP can make... consider a couple of them...

Or... are you only going to fly on warm days like today?

Best regards,

-a-

[xavierde]

- Plane usually sleeps indoor and was in the hangar before I flew on Friday afternoon. It was very cold though. 

- I use Aeroshell W100 with Camguard

- I preheat (cylinders and oil sump bands)

I will definitely look at the oil cooler and the vernatherm. 

[xavierde]

11 hours ago, MarkD34M said:

Have you checked the turbo carefully? 

Not since that flight. I have during the oil change.

[N231BN]

I used to run 100w throughout the winter since my 231 is always heated. I started having problems with the oil cooler congealing on cold days so I now switch to 20w-50 in the winter.

I really think that is what happened based on personal experience. When the oil gets that hot you will burn more in the cylinders so that's where your 1.5 qts went.



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[jrwilson]

5 hours ago, xavierde said:

- Plane usually sleeps indoor and was in the hangar before I flew on Friday afternoon. It was very cold though. 

- I use Aeroshell W100 with Camguard

- I preheat (cylinders and oil sump bands)

I will definitely look at the oil cooler and the vernatherm. 

I thought camguard wasn't approved for turbo use?  Probably not related to this problem though...

[tmo]

Those darn hangar elves, mixing stuff in...  Better hide them WD40 cans...

[carusoam]

For where the oil went...

As oil gets heated, it’s viscosity turns to watery-ish...

Its ability to slip past things like oil control rings increases....

If this was the route of escape... a quart of oil will probably be showing affects in the tail pipe... and belly of the plane.

If splashing around more... it may have headed for the case vent... affects would be seen at the case vent drain tube and belly of the plane...

Skipping past exhaust valves... another possibility...

Anytime oil is getting burned in the cylinders... expect to see crud And oil on the spark plugs in that cylinder...

PP thoughts only, not a mechanic...

Best regards,

-a-

[Western Flyer]

In my newly purchased 1980 Mooney 231, the oil temperature would climb to near red line and the oil pressure would drop to the bottom of the green soon after takeoff. Cylinder head temperatures seemed acceptable, staying in the upper third of the green. A mechanic at my local Mooney shop opened the cowl and immediately noticed that there were a few small gaps in the engine baffling, and the baffle seals were rolled forward. He told me that the seals would not blow back and seal against the upper cowl. He recommended replacing the baffle seals and sealing small gaps. What a difference! After having the work done, oil temp and pressure are staying comfortably in the green

Edited April 27, 2020 by Western Flyer

[carusoam]

Welcome aboard Western!

Great pirep on a first post!

Thanks for sharing the details...

Baffle seals are everything for good temp controls...

extra important when the oil cooler is at the back of the baffles...

Lets see if @xavierde is around today...   

Best regards,

-a-

[xavierde]

Thank you both, I'll add it to my (long) list of things to review during the annual. 

I haven't had any problems since that flight so I'm now convinced it was an issue with running the 100w on a very cold winter morning and without having pre-heated long enough. 

This is what I could see on a recent flight (running 22/2500 to let a J driver catch up with me @jkarch)