High oil temp when climbing

[Htmlkid]

I climb at 26/26 and I’ve noticed during the climb my oil temp has been going into the red around 230 degrees. Anyone experience this?

[carusoam]

few people climb at 26/26... 

As far as temp control goes there is a great piece written about vernatherms around here...

Sounds like it might be time to get yours tested for operability...

This is as simple as putting in a pot of water with a thermometer and heating it... when it opens record the temperature... check against the proper operation temperature....

If not the valve... the fins may be dirty on the outside....or the sludge build up on the inside has blocked some tubes...

If the whole oil cooler is ancient... there are services that OH them...

Where do you want to start...

• paper chase? Check the logs to see how old the devices are...
• simple maintenance? Clean the fins... use an IR thermometer to look for blocked tubes...
• medium maintenance with high probability of needing to be done... check the vernatherm.... 
• More complex maintenance? Clean the tubes out...
• ultimate solution? OH the oil cooler, and replace the hoses...

Vernatherms are mechanical devices and have a tendency to wear out over the years... they are simple to swap out...  

Got any JPI data showing OilT vs OAT?

To be extra serious for a moment... red zones for oilT are too serious to ignore... and probably easy to fix...

PP thoughts only not a  mechanic...

Best regards,

-a-

[Ragsf15e]

@carusoamhas good questions and your  the oil cooler/vernatherm could definitely be the issue, but lets do a little data collection first...

1. What speed are you climbing at?

2. Is this a new condition?  Have you had the plane long?

3.  What do your CHTs look like in climb?

4.  What does your oil pressure do as your oil temp climbs?

[MATTS875]

I’m having about the same issues. During my cruise I’m getting high temps of 225-230 with cowl flaps half open. I’ve overhauled the oil cooler and  still nothing changed. I’ve checked baffling and all is good. Just got my plane back from an engine overhaul about 3 hours ago and still having high oil temps. I’m definitely interested in any ideas that could help. 

[carusoam]

Anyone have any part of their oil cooler still blocked for winter?

Just checking...

-a-

[Ragsf15e]

42 minutes ago, MATTS875 said:

I’m having about the same issues. During my cruise I’m getting high temps of 225-230 with cowl flaps half open. I’ve overhauled the oil cooler and  still nothing changed. I’ve checked baffling and all is good. Just got my plane back from an engine overhaul about 3 hours ago and still having high oil temps. I’m definitely interested in any ideas that could help. 

Cruise is kind of a different animal.  Curious though... what is your oil pressure at takeoff and what does it do as oil temp rises up that high?

In climb, it’s common for people to see high oil temp by climbing at Vx or Vy for a long time, maybe running too lean in climb (thus hotter cht), etc.  in cruise, those usually aren’t issues.

Both cases need to make sure the reading is accurate which is why I asked about pressure.  Oil pressure is very sensitive to temp changes.  Very.  It will drop noticeably as temp rises.  On my JPI, I can start to see pressure drop a couple psi with ~10 degrees increase in Oil temp.

[Guest]

9 hours ago, Htmlkid said:

I climb at 26/26 and I’ve noticed during the climb my oil temp has been going into the red around 230 degrees. Anyone experience this?

What model of airplane do you own?

The first step is to confirm the accuracy of the data.  Is this from an original gauge or an engine monitor?  Remove the oil temperature thermocouple from the engine and boil it in water and see what the gauge reads.  Depending on your field elevation it should be very close to 212 F.

Clarence

[alextstone]

Vernatherm testing and replacement steps...

[Nippernaper]

I had problems with high oil temps (and associated low pressure) since I got my J about 2 years ago. The mechanic doing my annual finally figured it out; the oil lines to and from the oil cooler were quite old, and weren't allowing full flow. This was after checking the flow through the oil cooler itself and operation of the vernatherm.


Sent from my iPhone using Tapatalk

[MATTS875]

18 hours ago, Ragsf15e said:

Cruise is kind of a different animal.  Curious though... what is your oil pressure at takeoff and what does it do as oil temp rises up that high?

In climb, it’s common for people to see high oil temp by climbing at Vx or Vy for a long time, maybe running too lean in climb (thus hotter cht), etc.  in cruise, those usually aren’t issues.

Both cases need to make sure the reading is accurate which is why I asked about pressure.  Oil pressure is very sensitive to temp changes.  Very.  It will drop noticeably as temp rises.  On my JPI, I can start to see pressure drop a couple psi with ~10 degrees increase in Oil temp.

As the oil temp rises the pressure drops. I had it flown back to Jewell Aviation today and he is checking the baffling. Hopefully this will fix the problem

 

 

 

[Ragsf15e]

Good that you’re having it looked at.  Generally baffling cools the cylinders which can lead to cooler oil if they were running hot... were they upper 300s, maybe low 400s?  There is a piece of baffling on some airplanes that may or may not direct airflow away from the back of the oil cooler and allow more air to come through the front of it.  Some have it, some not.
 

 If chts were all 330-350, baffling is unlikely to help.  It will then be time to check out the vernatherm and/or oil cooler.

[MATTS875]

58 minutes ago, Ragsf15e said:

Good that you’re having it looked at.  Generally baffling cools the cylinders which can lead to cooler oil if they were running hot... were they upper 300s, maybe low 400s?  There is a piece of baffling on some airplanes that may or may not direct airflow away from the back of the oil cooler and allow more air to come through the front of it.  Some have it, some not.
 

 If chts were all 330-350, baffling is unlikely to help.  It will then be time to check out the vernatherm and/or oil cooler.

CHT,S were all running below 350. I’ve had the oil cooler sent off and completely overhauled. If this doesn’t work I might try new oil lines

[carusoam]

Check the oil lines while they are disconnected... kind of like a drain snake... to see if anything is hiding in them...

If ancient... they may be not holding their shape any longer...(?)
 

PP thoughts only...

Best regards,

-a-

 

[MATTS875]

12 hours ago, carusoam said:

Check the oil lines while they are disconnected... kind of like a drain snake... to see if anything is hiding in them...

If ancient... they may be not holding their shape any longer...(?)
 

PP thoughts only...

Best regards,

-a-

 

Thank you. I just emailed a Jewell and requested they be replaced. Hopefully this will help

[Htmlkid]

On 5/17/2020 at 9:44 PM, Ragsf15e said:

@carusoamhas good questions and your  the oil cooler/vernatherm could definitely be the issue, but lets do a little data collection first...

1. What speed are you climbing at?

2. Is this a new condition?  Have you had the plane long?

3.  What do your CHTs look like in climb?

4.  What does your oil pressure do as your oil temp climbs?

I’m climbing around 100 and it’s a new condition. It happens on extended climbs above 4000’. The cylinder head temps are normal. I’m not sure about the oil pressure. The temp on extended climbs gets to around 230 degrees. It goes away quickly when I level off.

[Htmlkid]

On 5/18/2020 at 6:56 AM, M20Doc said:

What model of airplane do you own?

The first step is to confirm the accuracy of the data.  Is this from an original gauge or an engine monitor?  Remove the oil temperature thermocouple from the engine and boil it in water and see what the gauge reads.  Depending on your field elevation it should be very close to 212 F.

Clarenceits

 

it’s a Mooney M20F and the data is from a JPI 730 temps get to 230 on extended climbs

[Ragsf15e]

1 hour ago, Htmlkid said:

I’m climbing around 100 and it’s a new condition. It happens on extended climbs above 4000’. The cylinder head temps are normal. I’m not sure about the oil pressure. The temp on extended climbs gets to around 230 degrees. It goes away quickly when I level off.

Interesting...  I have an 68F as well, here’s my thoughts/techniques...

So 100mph should be right around your Vy.  Generally a good place to be initially unless of course obstacles are a concern, then use Vx.  Most people will “cruise climb” above about 1000’agl and use around 120mph.  You will find only a slight reduction in climb rate, higher forward speed, better visibility, and much improved cylinder and oil cooling.

As you get higher (you said above 4,000’), the air gets thinner.  There are less molecules of air passing through the engine and oil cooler to remove heat.  Increasing speed definitely helps.  If you’re still climbing at 100mph at 4,000, you will see a definite improvement at 120mph.

The total amount of oil matters too as there’s more oil to “hold more heat”.  My engine likes 6 quarts.  If I put in 7, the oil temp holds better during a long summer climb.  5.5 quarts is not good for a long summer climb.  This doesn’t have much effect in cruise that I can see.

If your temp is legitimately that high, you should definitely be seeing a reduced oil pressure.  As opposed to the volume of oil helping a little, this is very noticeable.  Check oil pressure at takeoff and through the climb. 
 

Finally, mine is about 195 in climb at 120mph and 185 in cruise, but oat matters and I live in a cold place.  If yours is as high as you say and it’s new, probably better to get it checked.  Stuff like testing the sensor, the vernatherm, and the oil cooler lines is pretty easy.

[carusoam]

+1 on cruise climb above 1k’agl... 120 IAS...

It is a good combination of performance and engine cooling...

Air volume doesn’t change... but the density / cooling capacity sure does... 

PP thoughts only,

-a-

[Ragsf15e]

13 minutes ago, carusoam said:

+1 on cruise climb above 1k’agl... 120 IAS...

It is a good combination of performance and engine cooling...

Air volume doesn’t change... but the density / cooling capacity sure does... 

PP thoughts only,

-a-

Ok, you got me there, you’re right, the volume doesn’t change at all.  I should’ve explained that much better!  Thanks!

[MikeOH]

3 hours ago, Ragsf15e said:

Ok, you got me there, you’re right, the volume doesn’t change at all.  I should’ve explained that much better!  Thanks!

I didn't see where you said, 'volume.'. Your comment about fewer air molecules was spot on; you 'splained it fine

[Ragsf15e]

Well yeah, after Anthony caught my “volume” misuse, I sheepishly went back and edited it!

[ziggy122]

I've also been having high oil temps too in my M20C.   I've been pulling back the throttle in the climb to keep it below 230/aiming for below 225 (continuous range from POH) on the JPI, and been climbing up to 8500 to get the cooler air up high.   Seems like 4500' isn't high enough to maintain below 225 consistently at WOT.  I thought it was just the 100F+ days, but methinks I should go clean off the radiator now to start, and maybe dig in further A/R...  Appreciate the post!

Edited June 15, 2020 by ziggy122

[takair]

On 5/19/2020 at 4:07 PM, Htmlkid said:

 

it’s a Mooney M20F and the data is from a JPI 730 temps get to 230 on extended climbs

What does the ships gauge read?  Do you know where the JPI temp probe is mounted?  

[wburger1]

I was very close to the red on original garwin oil temp gauge even when it was 45 degrees outside climbing and in cruise.   Took out oil temp probe  and put it in 200 degree oil and it actually read 200.  Before I put it in oil it read OAT.  Then I took out vernatherm and put it in oil and heated the oil and it did not open until 225 degrees.  So I got a new vernatherm and now I am in the green even when 95 degrees outside.  One note is that when I heated the oil it took a really long time to cool the oil down. Like 15 minutes for just a few degrees.  My vernatherm was original to my 67 M20F. 

[Prior owner]

On 5/18/2020 at 9:28 PM, carusoam said:

Check the oil lines while they are disconnected... kind of like a drain snake... to see if anything is hiding in them...

If ancient... they may be not holding their shape any longer...(?)
 

PP thoughts only...

Best regards,

-a-

 

Here’s an obscure bit of info:

There is a ball bearing test that can be conducted on flexible lines...I believe 43.13 specifies the correct diameter ball bearing to use for each size hose. I have yet to meet an A&P who has a set of ball bearings for this purpose though... you drop the ball bearing in the hose, and if it makes it to the other end, then the inner diameter is within min spec.