No oil pressure

vmirv8bldr · #1 01-06-2012, 08:11 PM

Today I prepared the plane for first engine start and after topping off ht oil and removing the bottom plugs, hand propped several rotations, probably 20, then engaged the starter (plugs still out) hoping to see some pressure. None, zilch. I ran the starter for probably 10-15 seconds. I did this cycle a few times with no joy.

The engine came from Barrett and has run before (90 minutes on the dyno.) It was pickled by them a couple of years ago, dessicant plugs and all that. I added about 7qts of oil and the dipstick reads right at 8 at level flight attitude.

Any suggestions?

Thanks,
Bart

Ron Lee · #2 01-06-2012, 08:15 PM

Sensor wiring to your indicator to include grounding if required. Assume a simple problem first.

What is your indicator? Separate gauge? EFIS?

jbagley · #3 01-06-2012, 08:16 PM

Had the same problem.

My oil pressure indicator wasn't working. I was fortunate to have one of the local mechanics helping; he happened to have a mechanical oil pressure gauge that we could plug in quickly.

frankh · #4 01-06-2012, 08:26 PM

I notice that when i change the oil and spin the motor over with the plugs removed it can take about that long before I get any oil pressure indication.

Frank

N427EF · #5 01-06-2012, 09:17 PM

More like 30 seconds the first time you try to get oil pressure.
You really can't hurt that engine spinning it on the starter without plugs installed. I remember I had the same thoughts a couple of month ago.
It took about 3 tries of more than 10 seconds each to finally register oil pressure about 45 psi . It seems a very long time when you are grinding the starter and normally it would be but with the plugs removed you really are not putting any load on the crankshaft or its bearings.

Ironflight · #6 01-06-2012, 09:19 PM

It's very common to take a good thirty seconds of cranking (no plugs) to get an indication Bart. Remember that you've got air in the lines from the engine to the oil pressure gauge (or transducer, and you've also got an orifice in the fitting coming out of the engine. Common practice is to disconnect the line at the gauge/transducer, and hold the end in a rag while cranking. Once you get oil to that point, attach it to the gauge, and you'll have pressure.

skylor · #7 01-07-2012, 12:59 AM

Quote:

Originally Posted by frankh

I notice that when i change the oil and spin the motor over with the plugs removed it can take about that long before I get any oil pressure indication.

Frank

Note that it's perfectly OK and good practice to Pre-fill a new oil filter by hand prior to installing it when changing your oil. Obviously, if you have a standard horizontally mounted filter you don't want to fill it so full that the oil spills when you install it, but you can put a surprising amount of oil in. This helps th OP to come up much faster after an oil change.

Skylor

rv9av8tr · #8 01-07-2012, 01:45 AM

Paul is exactly right..... which is typical 8-)

ao.frog · #9 01-07-2012, 01:46 AM

I second Paul's suggestion.

I did the same prior to first start, and it took a surprisingly long time before oil came out of the line.

At first, there was a mix beetween oil and air coming out, but after a few sec's, there was steady oil-flow. After hooking up the line, oilpress-indication was there.

Let us know how it goes.

pierre smith · #10 01-07-2012, 06:00 AM

A friend of mine is fighting that problem with a Conti IO-520 that had to be disassembled after a prop strike.

After that 2 years of sitting, your oil pump has lost its prime and you can refill it by removing the oil filter and using a funnel and a piece of flexible clear plastic tubing, fill the oil pump from the center of the oil filter hole and turn the prop backwards so the pump gears suck the oil in from that end.

Best,