High Oil Pressure?

OkieAviator

OkieAviator

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OkieAviator
On take off today when I looked at the oil pressure it was into the black space between green and red. I was wheels up when I noticed so climbed out a bit and reduced my RPMs down to 2300-2400.

For note it's a 172N, 180 with an 0-360. I had exactly 6 qts (15w50) showing in preflight and the temp was about 40 outside, not sure what it was in the hangar and the plane started right up.

Typically I run the engine about 10 mins to get the oil temp into the green before I take off. Today I left the second it started moving up, so maybe 8 mins. Here's a few pictures I took. The one without the RPM was about 3 mins after takeoff, leaving the throttle full open. Then second was when I leveled out about 2500 AGL and throttled back to my normal cruise.


Three Questions-
1) Is the higher oil pressure on takeoff normal if the engine hasn't warmed up enough and it's pushing syrup through the engine?
2) Should I plan to throttle out a bit on longer climbs if the engine isn't completely warmed up?
3) What else could I do or is this completely normal and I'm over reacting because I'm a diaper baby?
 

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OkieAviator said:
On take off today when I looked at the oil pressure it was into the black space between green and red. I was wheels up when I noticed so climbed out a bit and reduced my RPMs down to 2300-2400.

For note it's a 172N, 180 with an 0-360. I had exactly 6 qts (15w50) showing in preflight and the temp was about 40 outside, not sure what it was in the hangar and the plane started right up.

Typically I run the engine about 10 mins to get the oil temp into the green before I take off. Today I left the second it started moving up, so maybe 8 mins. Here's a few pictures I took. The one without the RPM was about 3 mins after takeoff, leaving the throttle full open. Then second was when I leveled out about 2500 AGL and throttled back to my normal cruise.


Three Questions-
1) Is the higher oil pressure on takeoff normal if the engine hasn't warmed up enough and it's pushing syrup through the engine?
2) Should I plan to throttle out a bit on longer climbs if the engine isn't completely warmed up?
3) What else could I do or is this completely normal and I'm over reacting because I'm a diaper baby?
Click to expand...

1. Yes.
2. Yes.
3. Let it warm up a bit more. If the oil pressure is too high you can damage the oil cooler. Don't do it.

What grade oil do you run?
 
OkieAviator said:
On take off today when I looked at the oil pressure it was into the black space between green and red. I was wheels up when I noticed so climbed out a bit and reduced my RPMs down to 2300-2400.

For note it's a 172N, 180 with an 0-360. I had exactly 6 qts (15w50) showing in preflight and the temp was about 40 outside, not sure what it was in the hangar and the plane started right up.

Typically I run the engine about 10 mins to get the oil temp into the green before I take off. Today I left the second it started moving up, so maybe 8 mins. Here's a few pictures I took. The one without the RPM was about 3 mins after takeoff, leaving the throttle full open. Then second was when I leveled out about 2500 AGL and throttled back to my normal cruise.


Three Questions-
1) Is the higher oil pressure on takeoff normal if the engine hasn't warmed up enough and it's pushing syrup through the engine?
2) Should I plan to throttle out a bit on longer climbs if the engine isn't completely warmed up?
3) What else could I do or is this completely normal and I'm over reacting because I'm a diaper baby?
Click to expand...


There are several reasons why oil pressure can go up, most of them are pretty benign, one is not. This is not meant to scare you or serve as a diagnostic, but the moment you start hearing a knocking, reduce power to the bare minimum you need to make a close airport. When a main or rod bearing 'spins' and slips in its bore, the oil port gets blocked and oil flow stops. This creates an imbalance in the system and the system pressure goes up.

Not a very likely scenario at all, but if it happens, reduce power as soon as you can. The less power you carry, the longer you can carry it, in fact, there is enough oil splashing around in there, if you reduce it enough it will run quite a while.
 
Make a preheater. And get a cowl blanket or walmart sleeping bag to cover the cowl and block the inlets
 
OkieAviator said:
I have Aeroshell 15w50 in it (http://www.sportys.com/pilotShop/product/14464)

I have some Philips 66 20w50 mineral oil we used for the break-in period. Should I alternate that in while it's cold?
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I would only use the Phillips. It is not "mineral" oil in that sense (though it is all mineral oil regardless). The Aeroshell has a synthetic base stock in it that does not play well with AvGas.
 
Henning said:
I would only use the Phillips. It is not "mineral" oil in that sense (though it is all mineral oil regardless). The Aeroshell has a synthetic base stock in it that does not play well with AvGas.
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I just switched over from 15w50 to 20w50 with camguard, after reading some stuff about the 15w50 not being the best choice for some Continentals, the books says ether is fine, so between the costs and avalibility I went with 20w50, don't think it's much of a diffrence in quality ether way.

I think the OP would do well to just get the thing warmed up a little better, set the preheater up and go get breakfast, come back and takeoff.
 
What I remember is that red line is gauged for normal operations and Lycoming understands that oil pressure may run a little higher in a cold engine. I don't think you have reason to be concerned. I wish I could refer you to that Lycoming document but I can't find it at the moment.
 
Henning said:
There are several reasons why oil pressure can go up, most of them are pretty benign, one is not. This is not meant to scare you or serve as a diagnostic, but the moment you start hearing a knocking, reduce power to the bare minimum you need to make a close airport. When a main or rod bearing 'spins' and slips in its bore, the oil port gets blocked and oil flow stops. This creates an imbalance in the system and the system pressure goes up.

Not a very likely scenario at all, but if it happens, reduce power as soon as you can. The less power you carry, the longer you can carry it, in fact, there is enough oil splashing around in there, if you reduce it enough it will run quite a while.
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That's impossible, the 0-360 has a pressure regulator.
 
Tom-D said:
That's impossible, the 0-360 has a pressure regulator.
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It can't be overwhelmed?:dunno: I know a Chevy has a fixed pressure pop off that can still let you spike oil pressure when you spin a bearing.
 
Henning said:
It can't be overwhelmed?:dunno: I know a Chevy has a fixed pressure pop off that can still let you spike oil pressure when you spin a bearing.
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This isn't a chevy.
 
Tom-D said:
This isn't a chevy.
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Pressure bleed is pressure bleed regardless, it's not like it works different. If the pressure pick up is between the pump and regulator, the pressure on the gauge will go up some regardless.
 
Henning said:
Pressure bleed is pressure bleed regardless, it's not like it works different. If the pressure pick up is between the pump and regulator, the pressure on the gauge will go up some regardless.
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It's virtually impossible to spin a main bearing in a Lycoming. You should study the oil system for a 0-360.

 
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Tom-D said:
It's virtually impossible to spin a main bearing in a Lycoming. You should study the oil system for a 0-360.
Click to expand...

Yeah, I know, however rod bearings are a different matter. Regardless, I'm in no way raising an alarm, just mentioning something I would bump up a level on the attentiveness scale is all, and have a reaction plan at the front of my mind.

If I reduced throttle and heard a 'thock' after seeing an increase in oil pressure event, I would be more concerned than if I heard it without the rise.

As for not spinning the mains, I thought that is Bush's entire argument about not doing a full top end.
 
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Henning said:
Yeah, I know, however rod bearings are a different matter. Regardless, I'm in no way raising an alarm, just mentioning something I would bump up a level on the attentiveness scale is all, and have a reaction plan at the front of my mind.

If I reduced throttle and heard a 'thock' after seeing an increase in oil pressure event, I would be more concerned than if I heard it without the rise.
Click to expand...

When you destroy any bearing in the lower end the oil pressure will drop due to excess oil flow after the pressure regulator. the regulator will close in an attempt to provide the bearing more oil. After the regulator is fully closed the bearing clearance will increase, and there is no more oil flow to keep the pressure at normal levels.

Ask anyone who has had a failure of this type and they will tell you the first indication was no oil pressure

Your theory of a blockage in the system is simply wrong, because the pressure regulator will simply open and control the pressure at a set level. when you see the diagram of the Lycoming oil system you will see the regular is prior the the bearings in the flow within the engine. any blockage down stream from there will simply be compensated for.
 
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Tom-D said:
When you destroy any bearing in the lower end the oil pressure will drop due to excess oil flow after the pressure regulator. the regulator will close in an attempt to provide the bearing more oil. After the regulator is fully closed the bearing clearance will increase, and there is no more oil flow to keep the pressure at normal levels.

Ask anyone who has had a failure of this type and they will tell you the first indication was no oil pressure
Click to expand...

Unless the bearing moves in the bore and blocks the oiling flow, then you typically see a rise, and yes it can happen. I have had several of these failures when I lifted my foot in the traps and watched oil pressure peg and heard a rod start tapping moments later.
 
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Henning said:
Unless the bearing moves in the bore and blocks the oiling flow, then you typically see a rise, and yes it can happen.
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wrong again.
see my edit
 
Tom-D said:
wrong again.
see my edit
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I understand the pressure regulator. When you block flow through a gallery, the blocked flow creates a situation where the pressure relief is wide open and can't flow enough. It's designed to regulate a normal flow balanced between the pump volume and all the gallery flow under normal bearing tolerance variation.
 
Henning said:
I understand the pressure regulator. When you block flow through a gallery, the blocked flow creates a situation where the pressure relief is wide open and can't flow enough.
Click to expand...

You got it backwards.
 
Hello! The OP is talking about high oil pressure on take off! Think cold oil! Hello!
 
Henning said:
Most likely, although 40 isn't very cold.
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It is if the oil wasn't warmed up to 100F! I can red line my OP easily if I don't warm the oil up to 100F.

Remember, that is take off temp. If the plane has been sitting, and is not cold soaked in the teens the oil is not gonna warm up to temp in 8 mins of idling.
 
Just curious, did the pressure go back down once sufficiently warmed up? or did it stay high?
 
My O-360 shows the same symptoms. POH calls for warming oil to minimum of 75 degrees F before take off. I wait until 80 on my oil temperature gauge and take off. Oil pressure can reach 105 psig for a minute or so until the oil gets hotter (upper red line is 100). Then it falls to normal.

It had gone as high as 115 psig in the past until the shop adjusted the regulator out.

I think the gauge. It is part of a new engine analyzer with new transducer.
 
Geico266 said:
It is if the oil wasn't warmed up to 100F! I can red line my OP easily if I don't warm the oil up to 100F.

Remember, that is take off temp. If the plane has been sitting, and is not cold soaked in the teens the oil is not gonna warm up to temp in 8 mins of idling.
Click to expand...

That's what I mean, starting at 40°F, unless you have no taxi to do, and you do a real quick run up, you'll be seeing 100° oil most likely.
 
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