Tech help please: No Oil from the prop governor???

Thanks to this website, got a great deal on an new PCU5000X. However, after install tonight and two minute test run an 60+ oil pressure PSI, there is no oil making it from the prop governor, into the pad at the back of the engine thru the steel line to the front of the engine to feed the prop, and therefore no prop movement.

The engine is an O-360 A1A and the prop is a Hartzel Blended Airfoil CS.

I have rechecked and yes, the gasket is seated correctly between the governor and pad and yes, the prop governor holes are lined up with the two holes on the prop governor pad. intake and outlet I'm guessing.

When we disconnected the steel line that feeds the prop oil right behind the propeller connected to the front of the engine case, not a sign of oil. Disconnecting it down on the prop governor pad, small traces of oil but not much.

We pulled the spark plugs and turned the motor with the starter and it just barely spitted any oil out of the prop governor pad steel line outlet.

We then disconnected the PCU 5000X from the engine and it seemed full of oil. We again motored the engine with the starter and it squirted oil out of a hole in the governor pad.

So the mystery is, why are we not getting oil up to the prop? Why is the oil not getting up thru the steel line from the prop governor to the front of the engine?

Does it take awhile for the governor to 'prime' and so its not functioning yet? Does it take a long time to 'fill'? Is there an 'on' switch someshere?

I am very frustrated and can't find any knowledgable local help. It seems governors are a mystery to most mechanics??? If anyone has an idea, please let me know, we're stuck here???

Thanks in advance!

1700rpm

For us old woodward users you had to have the engine at 1700 rpm or more and cycle the control 3 times to get the system working. Any lower RPM and nothing would happen.

Could be the same for your governor

Gaskets

Are you sure you have the proper gasket. I got one that didn't have the holes correct for the PCU, it was lined up, looked correct but was missing a hole, hence no oil.
Also, I'm assuming you already had a c/s prop and the geared drive shaft for the governor was already installed.

Time to try a different governor

I bought a new Jihostroj governor when I got my propeller. And I had the same symptoms, very little, if any oil, at the front of the engine. Double checked the gasket,, etc. I ended up sending the governor back, and it turned out that, whatever the problem was; was inside the governor. (The replacement one they sent, worked fine).

Prop Governor

http://www.lycoming.textron.com/support/publications/service-instructions/pdfs/SI1462A.pdf

We had similiar problems although not exactly.
After ruling out the governor as the problem( had it bench checked)
you have to expand your thinking.
The above link to Lycoming's Service Letter has the information to build a plate to install on the governor pad. This plate allowed us to check the PSI of the oil feed to the governor. Ours was normal oil pressure plus some, but next, and this was the key to finding our problem, was to hook a plastic tubing line to the plate and check "flow".....we found our flow to be only 1 gt a minute and the PCU guys said it was capable of 8 qts. per minute. So we knew we had a supply problem.
Couple things to check.
Remove the governor drive adapter and check that the correct gasket is in place. Then check the drive adapter for blockage, by removing the small plug
in the casing and sliding something thru to make sure the machined passage ways are clear. Next, and while the drive adapter is off, go to the top of the accessory case and look for the plug on the top of the oil gally, it may be plugged or have a temp prob or something. If memory serves me right, it is next to the tach drive and under the case vent outlet. Remove the plug and look down the passageway, all the way to the bottom at the governor drive adapter, it sould be very clear! The oil pump is right behind this galleyway. So if the passage is clear and the engine oil pressure is normal, and the drive adapter is good, then you most likely have something robbing your oil supply, like a bad/improper bearing assembly. Don't ask me how I know!
You didn't give any background info on the engine like new/overhauled, converting from FP to C/s etc.....so I'll stop here.
Good luck

CW or CCW

Have you checked that the rotation of the prop governor drive is compatible with the way the governor is set up? Don't ask.

Thanks Doug R for the highlight!

First of all, thanks to Doug R for highlighting this thread. This newest situation has really caused me some frustration. Thanks also to the inputs so far. To answer a couple questions, yes, this is a newly overhauled engine that came off a Beech Travelair that had a feathering CS prop. I had to change the prop governor because it was set up to drive to feather rather than to drive to fine pitch losing oil. So I bought the PCU5000X. I have been on the phone with them all morning and they are being very helpful trying to figure this one out.

Oil is in the governor, well, it's on the hanger floor now. But when I removed the governor last night, lots of oil. However NONE to the 'servo discharge line' (word I learned this morning). Up at the noise of the plane it is dry, hardly anthing at the governor pad exit. So it appears that oil is getting to the unit but not leaving the PCU5000X.

Ideas so far is that the gear ratio may not be the 'standard' O-360 A1A ratio and therefore the counterweights in the PCU are not spinning up to release the line that tells the system to send oil. Or for some reason the pump is simply not putting out. FYI, according the the PCU folks, that pump should be putting out 300 PSI so SOMETHING should be coming out of the pump, if it is working correctly/allowed to work.

Another idea may be the control lever is not moving enough to begin circulation since if it is at its stop limits it stops flow. However that is just 60 degrees of movement needed and I have that easily.

YUCK! Anyway, it certainly hasn't been plug and play but have been very impressed with the PCU5000 folks, notably 'John' and their help. They have already said they will test and replace if necessary.....and it might come to that.

Thanks again everybody! It's like a black science!

Confirm with the governor people weather the "A" hole or the "B" hole in the governor should be plugged for your particular propeller and installation, then check to make sure the proper hole in the governor is actually plugged. There could be a problem there causing this type of an issue. If there is oil to the governor and none coming out of it, I think the solution is obvious.
Good Luck,
Mahlon
?The opinions and information provided in this and all of my posts are hopefully helpful to you. Please use the information provided responsibly and at your own risk."

I agree with Mahlon

JJ, I used an MT Govenor from Van's on the sister engine, reclocked it and it worked perfect. I think your problem may be in the A-B plug Mahlon is speaking of.

Good Luck

No A and B

Hey guys,

Just spoke with John at the PCU5000X company, there is no A and B on the PCU. It is either a flat pitch or a coarse pitch unit, can't be switched.

I am going to re-look at my linkage and make sure my movement is enough and if it is I am going to send it in and have it checked.

No DAR for me next weekend...

testing

JJ,
When I sent mine back to American Propeller for testing, it tested fine.
So they charged me 100. fee for the testing!
I live in Virginia and sent it to California.....thinking there was something wrong
and it would be fixed under warranty.
Given the time for shipping, think about having it checked out locally.
It might save a lot of time and maybe money too.
If there is something wrong, then you could send it back!
Or at least ask them if they are going to charge you to test it!
Just food for thought!

ps......I was told from one of the guys at American Propeller...they have never had a defective PCU unit YET!!

The plot thickens!

Flew down to Meacham Field this a.m. for a test of the PCU5000X at Byam Propeller Service. Carl himself, assisted by Bryan, did the testing and both my governors tested good. And both them and John at PCU are completely baffled as to why I'm not getting oil on my application. I am taking the advice from this post listing and doing the Lycoming sevice instruction but was told that until I get oil flowing thru the line from the governor to the front of the engine/prop, my problem is still more basic than the service instruction covers.

I have an obstuction or bad gasket or something that is not allowing oil to move from the governor pad...even tho the governor appears to be gettiing oil.

Oh well, no one said homebuilding would be boring!

BTW, I haven't met too many people nicer or more accommodating than Carl at Byam...great guys and I'd recommend the shop.

Do the test.

Jetj01 said:

I am taking the advice from this post listing and doing the Lycoming sevice instruction but was told that until I get oil flowing thru the line from the governor to the front of the engine/prop, my problem is still more basic than the service instruction covers.

I have an obstuction or bad gasket or something that is not allowing oil to move from the governor pad...even tho the governor appears to be gettiing oil.

Click to expand...

JJ, I agree.
The service instruction mainly is to check the nose assembly, but the "plate"
it talks about and shows how to make will allow you to check oil pressure and flow to the governor......this is very useful information.

BTW.......I had the same situation you have except I was converting a FP to a CS and my problem was the nose assembly. The testing of the oil pressure and flow at the governor pointed me to the nose assembly. My bad front bearing assembly was robbing my oil flow so much the governor was starved for oil volume. Like I said, I had normal engine oil pressure, but only 1gt per minute flow.
What puzzles me is that your engine was turning a C/S prop already!
So what is different from the original setup?? The Governor is, but that was checked and found to be fine.....I'm puzzled.
Good Luck.

Thank Bob!

Bob,

Your posts have been very helpful and I believe our engine issues may be closely related. THANKS!

I pressure tested my assembly tonight. It seems that unless I block off the 'blowby' tube, I can't develope pressure at the crankshaft. If i put my finger over the blowby tube (on the back of the engine next to the oil supply lines. The tube normally goes to an air oil seperator...) then pressure builds up at the chamber in front of the block of the crankshaft. I did take my prop off tonight o make SURE i had the appropriate plug in...i do.

Thinking about it tho, since I'm 'blowing' air into the governor pad, would it not be normal for the air to also go into the engine since that is the direction of flow, rather than the way oil would be coming out of the orifice into the prop governor. This air going into the case woiuld be releived at the blowby tube...I think. Long story short, I could not get the prop blades to move because so much air was escaping into the case and exiting the blowby port.

I truly am experimental here since I have no real clue what I'm doing, just slowly eliminating ideas. One A & P I talked to tonight told me just to run the engine with the governor on for an extended period and see if it finally gets right....I don't know. i think I'm getting the idea on experimental anyway...the going 'mental' part! Ha!

keep after it!

Jetj01 said:

Bob,

Your posts have been very helpful and I believe our engine issues may be closely related. THANKS!

I pressure tested my assembly tonight. It seems that unless I block off the 'blowby' tube, I can't develope pressure at the crankshaft. If i put my finger over the blowby tube (on the back of the engine next to the oil supply lines. The tube normally goes to an air oil seperator...) then pressure builds up at the chamber in front of the block of the crankshaft. I did take my prop off tonight o make SURE i had the appropriate plug in...i do.

Thinking about it tho, since I'm 'blowing' air into the governor pad, would it not be normal for the air to also go into the engine since that is the direction of flow, rather than the way oil would be coming out of the orifice into the prop governor. This air going into the case woiuld be releived at the blowby tube...I think. Long story short, I could not get the prop blades to move because so much air was escaping into the case and exiting the blowby port.

I truly am experimental here since I have no real clue what I'm doing, just slowly eliminating ideas. One A & P I talked to tonight told me just to run the engine with the governor on for an extended period and see if it finally gets right....I don't know. i think I'm getting the idea on experimental anyway...the going 'mental' part! Ha!

Click to expand...

JJ......glad my posts are helping....sorry you are having the problem.
I may not be reading your post right, but you should be blowing or actually using a compression differencial pressure tester on the nose fitting on the side of the engine behind the prop. That will be putting the air directly into the nose assembly. Maybe you made the plate and hooked the air up correctly to go to the prop......that might be what you mean.

To confirm.....you have followed the instructions in the service instructions and did the nose test and it "failed" ????
yes, the air that leaks by the bearing assembly goes into the crankcase....
I opened my oil filler tube and listened. Some leaking by is normal....
but it is suposed to hold a little pressure like 8lbs....I think!
If it doesn't hold any pressure......something is wrong.

another test that I did:
I bought a 0-400 psi liquid filled gauge from Northern Tool and hooked it up to the governor output......I got flucuating reading from 0 to 300 for a second or two then back to 0....
I did the same test to a known working RV with the same setup....it showed 325 or so....steady!!!!....of course with the appropriate cable input!
Assuming the governor is working(because of being tested) if the governor doesn't get "enough" oil.......it will not work correctly.
This test failure lead me to test pressure and flow "to" to governor.
my poor test results lead me to verify the oil galley was open.....
then once I confirmed the oil galley was open....it had to be the NOSE!

I can't see how putting it together and flying it would help at all....my .02.
I'm still puzzled that the original set up worked!
Keep after it, you will get it!
Good Luck.

It looks like you have already talked to many people smarter than me, but I'll give it a shot.

1. I would loosen the governor line at the front of the engine, pull the prop control to full aft, and crank the sucker to see if I could get any flow out. Ignore for now the crankshaft and chamber side.

2. If you get flow, and I believe from my understanding of whats going on, you should. Hook it back up, run the engine.. Once warm bring rpm up and start moving the prop control back. At about 2000rpm, you should be able to pull the prop control about halfway out and wait for the darn thing to start governing...

Even with a less-than-perfect seal up front, the PCU5000 should have enough umph to get it moving a little bit.

Governor operation

I have read this whole thread a couple of times and have a few questions/comments. It isn't clear how the engine was operated during the initial test. For the governor to send oil to the prop two things need to happen, the RPM has to be around 1700 minimum and the prop control needs to be pulled aft slightly. With the prop control at high RPM, the governor won't send any oil until you hit max RPM, probably around 2700. The governor is basically an adjustable RPM sensitive valve. The other issue is purging the air out of the system, especially the prop itself on a first run. As Gary stated in the second post, it will take a few cycles of the prop at runup RPM to purge the air.

John Clark ATP, CFI
EAA Flight Advisor
RV8 N18U "Sunshine"
KSBA

The problem found....darn it!

This morning an A&P, John W, from Emporia, KS called and told me he had been doing some research. He asked me to remove the line from the elbow going into the nose of the case coming from the prop governor pad. This is the line that should feed oil to the prop. He said to blow thru that hole while placing my hand over the crankshaft opening in front. I had already removed the prop last night to be sure about my crankcase plugs being in place and sound (they are). He said that the pressure should build in the crankshaft cylinder and be able to blow my hand off the front.

So I did this test and no, no pressure building. You could hear it escaping. The only way to get pressure to build was to plug off the crankcase vent line and dip stick.

Long story short, and it has been long...it appears when this O-360 A1A was overhauled before I bought it, the case was sent in for overhaul and the case was sent back as a fixed pitch case, ie. there was a hole made to send oil back to the case from the front bearing area. I think that makes it an O-360 A4M. Anyway, I have to remove the engine and send it in to get the case repaired back to a constant speed setup. This motor is a yellow tagged, certified motor that was overhauled to be reused by a Beechraft Travelair so it was supposed to be a constant speed engine. Appears a mistake may have been made in assembly.

We'll see. My plan is to take the engine back off my -4 and send it to get repaired.

Thanks to EVERYONE for all your help in the diagnosis. Couldn't have done it without you!

No DAR this weekend!

Jetj01 said:

Long story short, and it has been long...it appears when this O-360 A1A was overhauled before I bought it, the case was sent in for overhaul and the case was sent back as a fixed pitch case, ie. there was a hole made to send oil back to the case from the front bearing area. I think that makes it an O-360 A4M. Anyway, I have to remove the engine and send it in to get the case repaired back to a constant speed setup. This motor is a yellow tagged, certified motor that was overhauled to be reused by a Beechraft Travelair so it was supposed to be a constant speed engine. Appears a mistake may have been made in assembly.

We'll see. My plan is to take the engine back off my -4 and send it to get repaired.

Thanks to EVERYONE for all your help in the diagnosis. Couldn't have done it without you!

No DAR this weekend!

Click to expand...

If it makes you feel a little bit better, this is not the first time I have seen this (and it probably will not be the last).
There is a Lycoming service instruction for testing the leak-down rate on the nose section of the engine, but I didn't mention it because you said you had tested for oil output from the governer and that there was none.