Fixing my oil temp/press issue w/a steep climb

timwinters

timwinters

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For those of you who thought I was crazy...or lying...here's the proof of what I've been saying about my oil temp/press issues.

Sorry for the bouncing, it was a bumpy day around here yesterday. I tried to edit out the worst bouncing so you didn't get vertigo while watching.

Edit: One data point I failed to include in the video...OAT = 75dF at cruise altitude.

 
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What was the problem you were having? I'm not familiar with the history of this.
 
Clark1961 said:
Time to get yer chemistry checked. Yer imagining everything.
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Well, they did bust the local pot supplier here just last week. 400+ plants on his property and over 10 pounds processed in his house.

So much for my mind altering excursions for a while. He's going to be hard to replace. I might have to come visit you, Clark! :goofy:
 
Holy ****...YGBFSM!!...WTF??...and every other exclamation you can think of.

My engine was overhauled, the ONLY thing that was reused was the case.

And...

I still have this same issue...

Flew it four hours yesterday. Oil temp was 180 and pressure 39 in level flight @4500'. Pressure hasn't been where I like to see it since OH...upper 30's...low 40's. I like seeing 50. Thought it was just an adjustment issue.

So I thought...what the hell??...and yanked the yoke back into a steep climb of 2000fpm, climbed 500', leveled off, then rolled the trim slightly forward for a 300 fpm descent back down to 4500'. By the time I got back to 4500' the oil temp had dropped 20dF and the pressure had risen to 50. And it stayed there for the duration of the flight, about two hours. No throttle, prop, or mixture settings were changed during the climb.

WTF?

CHTs and EGTs don't change.

And it's not a sensor/indication issue because both my engine monitor and stock gauges show the change and they are completely independent of each other.

(Oh, and we changed the location of the oil temp probe during the OH, it was in the sump. Now it's just downstream of the oil cooler, best I can tell, it reads 20dF cooler in the new location.)
 
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My post from last year quoted below. Since the condition still exists, it might be a little more credible than before. Is there any visible difference between the cooling air inlets on your 182 vs. others such as smoothness of finish or perhaps a bent piece of sheetmetal? Are there any after market configuration changes inside your cowling that could affect the air flow path compared to stock? Not very feasible but it would be interesting to know if VGs in the inlets would have any effect.

An everyday example of meta-stable fluid flow is what is known as "hydraulic jump" in a stream. Since there are two solutions of depth/velocity conditions that satisfy conservation of energy in the fluid flow equation, the stream can jump back and forth between a deeper/slower and a shallower/faster condition.

"Tim, I have seen meta-stable fluid flow patterns shifting back and forth with no discernable trigger. Air is a (compressible) fluid. Pretty far fetched but could the maneuvering trigger shifts in the air flow pattern through the engine compartment that result in different air pressures at the back side of the cooler? This would change the air flow through the cooler. This would not account for the changes after an oil change. or - if the temperature in the sump isn't totally homogenous, flow pattern shifts in the sump could result in picking up warmer or cooler oil.

Where I've seen this is was in the outlet pipe (hot leg) of a power plant reactor with water at about 2000 psi and 500 plus degrees. The outlet temperature across the top of the core is not uniform across about a 12 ft. diameter and had not become totally mixed before reaching the temperature sensor in the hot leg. At steady state conditions, the indicated temperature would shift between two different values as the flow pattern shifted from one meta-stable condition to the other."​
 
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Bobby,

I'm starting to think that's about the only thing it can be. It's the only constant..."it" being the installation.

All cowling and baffling is original design, no modifications. New baffling (flex seal) was installed at the OH. The rigid baffling was IRAN'ed.
 
Those temps and pressures seem fine to me. 180F and 40psi is good. 160 and 50psi is good. The oil is thicker at cooler temps. Your 300fpm descent raised airflow through the cylinders and oil cooler, its completely expected that the oil will cool, become more viscous and the pressure will be higher.
 
Seeing these numbers vary some without having an exact correlation is fine, because of the location of the temp and pressure sensors.
 
Checkout_my_Six said:
bad gauge......lol
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timwinters said:
And it's not a sensor/indication issue because both my engine monitor and stock gauges show the change and they are completely independent of each other.
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dell30rb said:
Your 300fpm descent raised airflow through the cylinders and oil cooler, its completely expected that the oil will cool, become more viscous and the pressure will be higher.
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timwinters said:
And it stayed there for the duration of the flight, about two hours.
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Some of you guys really need remedial reading comprehension tutoring. :smirk:
 
Does your engine have a thermostat that controls the flow through the oil cooler? Cowl flaps on that older 182?

I watched the video. I'm seeing that you have an oil temp of close to 200F and oil PSI around 40. You pop up 500' quickly and level off. Oil temp starts dropping and oil pressure rises, about 20F and 10psi respectively.

If you have cowl flaps, my guess is that you take off and level at 1500ft, accelerate to cruise speed, then close them? The air is pushing on them and they close tightly. Then you pull 2.5 G and airspeed falls to 60-70kt. Maybe they are opening a bit due to some slack or misalignment in the system, and staying that way.
 
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Yes, it's called a vernatherm. It is new.

I also replaced it last summer with a new one when first experiencing the issue...no change. So now I have two for sale! (Seriously)

No cowl flaps.
 
dell30rb said:
Does your engine have a thermostat that controls the flow through the oil cooler? Cowl flaps on that older 182?
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Nope. He has an A model and cowl flaps came out first on the '59 B models. BTW, does anybody know if there is an aftermarket mod to put cowl flaps on the A model?

Thanks,

Jim
 
Could you try this with the mixture pig rich, see if you get the same result?

Without touching any power settings, climbing 500' could change your air/fuel ratio enough to get you out of a hot running power setting or very minor detonation.
 
Crazy thought time: Something wonky going on in your prop? Sticky relief valve there or contamination/crud in it?

I didn't see whether you overhauled your prop with the engine or if you had any metal contamination which would mandate doing so.
 
Nate,

Prop was IRAN'ed and governor was overhauled. There was no contamination in the screen when disassembled. It was a good thought though. Thanks!

I wonder is maybe there was a crack in the pickup tube that was missed during OH. I can't explain why the temps/press would remain corrected for hours if this was the problem though.

It's like something is losing prime and a steep climb fixes it.

I might try pulling the oil filter adapter (pistol grip style) off of it, reinstalling a stock screen, and seeing if that makes a difference. Though the oil filter adapter is new also, I went from an F&M to an OEM model and from an 08 filter to a 10.
 
dell30rb said:
Could you try this with the mixture pig rich, see if you get the same result?
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I've been running it pretty rich since day one since I'm breaking it in. 14 to 15 GPH.

dell30rb said:
Without touching any power settings, climbing 500' could change your air/fuel ratio enough to get you out of a hot running power setting or very minor detonation.
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Yes, but I descended to the original altitude within a few minutes and stayed there to my destination.
 
What does your builder have to say about it?
 
best guess is vernatherm not quite opening all the way and the induced stress/heat of the climb gets it to "pop" that last little bit...
 
jaybee said:
best guess is vernatherm not quite opening all the way and the induced stress/heat of the climb gets it to "pop" that last little bit...
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Yeah, but... he's on Vernatherm number three, I believe now.

Just continuing on "crazy train" thoughts for you @timwinters - thinking in terms of contamination and plugged up stuff... was the oil cooler itself new or the old one? Sent to a shop for a pressure clean out? Crud stuck in there that the maneuver gets out of the way for a while?

That's a horrible idea, but it's the best I've got...
 
@denverpilot

I'm not sure if the cooler is new but it was definitely overhauled. Everything was gone thru.

And you're right. I'm on vernatherm #3 since this started.
 
denverpilot said:
Yeah, but... he's on Vernatherm number three, I believe now.

Just continuing on "crazy train" thoughts for you @timwinters - thinking in terms of contamination and plugged up stuff... was the oil cooler itself new or the old one? Sent to a shop for a pressure clean out? Crud stuck in there that the maneuver gets out of the way for a while?

That's a horrible idea, but it's the best I've got...
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25 years of mechanicing... new don't mean ****... but... yes, three with the same symptom unlikely(that is the case right?). in fact, in the biz - NEW means Never Ever Worked ;)
 
timwinters said:
@denverpilot

I'm not sure if the cooler is new but it was definitely overhauled. Everything was gone thru.

And you're right. I'm on vernatherm #3 since this started.
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I'm more concerned about how it was "overhauled".

It's usually specialty shops that can clean them out when they're gunked up. If all some place did was straighten out any bent fins for airflow and clean the outside...

Dunno. It's a sucky idea anyway. :(
 
image.jpg Nate, it looks brand new. Also, I took the old one off and had a local radiator shop boil it out last summer when the problem first popped up. It had some gunk inside, they cleaned it up nicely. Made no change.

Keep the ideas coming though...
 
Well with a head scratcher like that one, I think I'd be willing to give John Frank a call at CPA just to see if he's got any similar weirdness filed away in his brain from years past.

Or maybe the guy Troy used for his pre-buy on his 182RG. Umm. John Effinger I think? Troy?
 
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