Quick oil pressure question

Morgan3820

Morgan3820

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Just installed an EI CGR-30P. All is fine except at run-up the oil pressure is reading 140 psi !

OP appears to be normal at idle.

Any ideas?
 
Is the oil pressure relief valve stuck? It may leak down enough through bearings at idle, and go high otherwise. Also good to stick another gauge in there, to see if the numbers are accurate.
 
If you have the original gauge and plumbing, could you hook it back up to see what that says? (I assume the -30P is a digital oil P replacement)
 
Kenny Phillips said:
Is the oil pressure relief valve stuck? It may leak down enough through bearings at idle, and go high otherwise. Also good to stick another gauge in there, to see if the numbers are accurate.
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Yes, a dirty oil pressure relief valve is on the list of things to look at, as is hooking up another gauge.

The old analogue gauge didn't previously show abnormal high readings except on startup when it would go past redline until warm-up.

Is a dirty relief valve common?
 
Morgan3820 said:
Just installed an EI CGR-30P. All is fine except at run-up the oil pressure is reading 140 psi !

OP appears to be normal at idle.

Any ideas?
Click to expand...

This, combined with your subsequent post about the oil pressure being over redline at startup until the engine warms up, sounds to me like someone has screwed the relief valve adjustment down tight. You risk blowing an oil filter apart that way.

What engine is it? Lyc and Continental have different relief valves. Lycoming's is very unlikely to stick.
 
I wouldn't be flying it if mine, until I had it checked out, and if the pressure is actually that high, the cause was repaired. 80 psi is fine, 140 is really bad.
 
Ok, today we disassembled/cleaned the relief valve. Oil pressure still at 108 psi at 2000rpm. tomorrow We are going to borrow a calibrated mechanical gauge to compare against the CGR-30P. We were unable to adjust the screw on the relief valve as it was too tight, like a locknut is under the cap but the cap does not want to come off. I wish that I took a picture to show y’all. This is the screw type adjustment, not the stacked washer type.
 
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Dan Thomas said:
This, combined with your subsequent post about the oil pressure being over redline at startup until the engine warms up, sounds to me like someone has screwed the relief valve adjustment down tight. You risk blowing an oil filter apart that way.

What engine is it? Lyc and Continental have different relief valves. Lycoming's is very unlikely to stick.
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Lycoming. Do you know if there is a locknut under the cap?
 
Morgan3820 said:
Lycoming. Do you know if there is a locknut under the cap?
Click to expand...

There isn't. The threaded shaft runs a plastic (teflon?) piston back and forth, and the piston puts pressure on the spring. The piston seals against the housing so oil doesn't seep past the threads, and the piston's friction holds the adjustment in place.
 
Dan Thomas said:
There isn't. The threaded shaft runs a plastic (teflon?) piston back and forth, and the piston puts pressure on the spring. The piston seals against the housing so oil doesn't seep past the threads, and the piston's friction holds the adjustment in place.
Click to expand...

Why is the thread so tight? we stopped because we felt that we might break it.
 
Morgan3820 said:
Why is the thread so tight? we stopped because we felt that we might break it.
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Are you turning the right thing/ The nut pinned on the threaded shaft?

FP03072011A0007K.jpg



If it won't turn, something is seized. Parts for that assembly aren't available. It comes as a complete assembly.

Maybe you have the older style with the metal cap that retains an oil seal on the threads. Doesn't have the plastic piston.

Oil%20Pressure%20Relief%20Valve.jpg
 
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Yes, Turning the nut. I was starting to feel the roll pin bend. I will know more tomorrow when we put the calibrated gauge on.
What bothers me is that I may have been flying around not knowing that my oil pressure was past redline.
 
I have the same rig as yours, past redline on startup is common on these Lyco IO-360s. It comes down with warmup. Worse in the winter than in the summer. I have the same reading profiles as you did on your stock gauge for the last 6 years. 400 hours and I haven't died yet. I have a stock gauge as well. I bet your electronic doo dad is reading wrong. Be that as it may, the "hard to turn" symptom on the regulating valve might warrant attention on its own merit.

We'll see what the mechanical gauge says when you hook it up and warm up the engine. Considering you haven't blown an oil filter yet, my guess is it reads in limits once warm. Good luck and keep us posted!
 
Morgan3820 said:
Yes, Turning the nut. I was starting to feel the roll pin bend. I will know more tomorrow when we put the calibrated gauge on.
What bothers me is that I may have been flying around not knowing that my oil pressure was past redline.
Click to expand...

If it is that tight, you need a new assembly anyway...
 
Ok, the calibrated gauge reads in perfect agreement with the value on the new engine monitor. So, hopefully the new pressure regulator will resolve the issue.
 
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