Zero Oil Pressure - Page 4

Mark Dickens · #31 07-09-2019, 09:13 AM

Quote:

Originally Posted by William

Have you removed the oil pressure relief valve and inspected for debris under the ball?

Bill

I did remove the valve to inspect it, but I probably didn't inspect the ball seat as well as I should have. I'll do that this afternoon. Nothing was visible but again I didn't get down and really hawk it

skylor · #32 07-09-2019, 10:05 AM

Quote:

Originally Posted by Mark Dickens

I did remove the valve to inspect it, but I probably didn't inspect the ball seat as well as I should have. I'll do that this afternoon. Nothing was visible but again I didn't get down and really hawk it

Is it possible something has gotten into the sump (rag) that could be blocking the oil pick-up tube?

Skylor
RV-8

Mark Dickens · #33 07-09-2019, 03:06 PM

Quote:

Originally Posted by Mark Dickens

I did remove the valve to inspect it, but I probably didn't inspect the ball seat as well as I should have. I'll do that this afternoon. Nothing was visible but again I didn't get down and really hawk it

I did it again this time with a flashlight and magnet. Other than a microscopic sliver of metal about the size of a small hair, nothing was found. I don't think this is the issue, unfortunately.

airguy · #34 07-09-2019, 03:36 PM

Blown gasket on the governor? Can it bypass that much oil in that case?

Mark Dickens · #35 07-09-2019, 03:51 PM

Quote:

Originally Posted by airguy

Blown gasket on the governor? Can it bypass that much oil in that case?

Another good question I can't answer but I can think hard about. As frustrating as this has been, it's been a puzzle to solve, and I like doing that. I still do not understand how the oil cooler gets hot if the oil pump is dead...

mahlon_r · #36 07-09-2019, 04:56 PM

no oil flow out of the pump from that fitting will not produce metal in the filter or at the relief valve. There was no flow. that fitting goes directly into the oil pump output port. No flow there no flow anywhere. Either the oil pump failed or the suction screen is blocked. Nothing down stream from the pump could cause no flow out the center oil cooler fitting. BTW Mark the plug missing from the rear on the crank shaft nose section will not cause zero oil pressure. The prop won't work so good but you would still have pressure. Also, even with the relief valve ball out of the engine, you will still have about 50 psi oil pressure at power. Really low at idle but you would still have pressure.
Why was the cooler hot? Can't say. Hot air from the cylinders blowing on it? In a normal situation, there is just a very little flow through the cooler if you have a vernatherm installed until you get the oil to temperature (150- 165F plus). If you did a couple of quick runs to power from cold status, the oil cooler wouldn't normally get any flow, until you got the oil pretty hot. So the cooler wouldn't start to get hot from oil flow until you had at least above 150f oil in the sump.
Hope there was enough residual oil on the bearings and at the front thrust surface to have prevented any serious damage but the only way to tell for sure is to look. Especially at that front thrust area of the case and shaft, really susceptible with no oil flow there.
Good Luck,
Mahlon

Mark Dickens · #37 07-09-2019, 05:55 PM

At this point, it seems to be only a matter of choosing an engine shop. I have a quote from Continental/Titan. I will be getting at least two others. Barrett will be one of them. Recommendations are welcome. PM if you want.

Thanks to Mahlon for his input. I do have the Dynon data logs at the office and will take a look at the CHTs to see if heat from the #2 and #4 cylinders could have heated the cooler up, but it's really no matter since the engine has to be looked at. It's really more a matter of curiosity at this point.

Toobuilder · #38 07-09-2019, 06:10 PM

Did I miss it in the thread, but what does the suction screen look like?

Mark Dickens · #39 07-09-2019, 06:15 PM

Quote:

Originally Posted by Toobuilder

Did I miss it in the thread, but what does the suction screen look like?

I pulled it early in the process. 1-2 very small carbon specks. I showed it to a local A&P/IA who happened by the hangar and his comment was "that's normal".

William · #40 07-09-2019, 06:47 PM

Do you know if your oil pickup tube is attached to the lower face of the accessory housing? Most older Lycoming o-320s use this type of pickup. perhaps the safety wire was not installed and the screws backed out and the pickup tube fell off the accessory case mount. Just another way you could end up with 0 psi oil pressure. Being your engine is a new 370; I don’t think they use this configuration of oil pickup. Could be wrong though.

Bill