Oil Analysis

ablight · Post by **ablight** » Fri Mar 28, 2008 14:29

I received a call from Avlabs today. I am told my Iron PPM is 74. Last oil change it was 22. They told me inactivity could be the cause (corrosion) but to have a compression check ASAP. Any thoughts? C85-12F with 0200 STC. New milleniums - 90 hours TT. Andy

Nathan K. Hammond · Post by **Nathan K. Hammond** » Sat Mar 29, 2008 01:58

Hey Andy,

Don't fret over one bad analysis; instead look at the trend. One bad reading isn't something to worry about, but if you get 3 or 4 high readings in a row, then you might want to investigate a little closer. I'd run the engine for another 2 oil changes, then see if it was a one-timer or an honest trend of high iron.

On the good side, it's a very low time engine and is probably still finding it's home, hence the metal. Plus iron is most likely the rings which take the most beating, especially if the airplane sits for extended periods (3-4 weeks) without use.

Did the airplane sit for a while? How much time on the oil?

nkh

CptKelly · Post by **CptKelly** » Sat Mar 29, 2008 09:27

The first thing I'd do is to check for particle size foreign material in the oil. Check the screens or oil filter. If nothing is there, the contaminant is microscopic, and not of immediate concern. At 90 hours, you are probablly still picking up overhaul generated contaminants, so, if the screens (or oil filter) is clear, like Nathan said, look for the trend in future oil analysis tests.

Mike

ablight · Post by **ablight** » Sun Mar 30, 2008 20:32

I have a spin on filter. Cut it open and not much was there. Little brass colored particles, and not many. The engine did sit for about 3 weeks between flights this winter. Terrible WX... My last 4 samples were 19, 69, 22, and 74 for Iron. Can't figure out the ups and downs. Thanks for the replies...Andy

Nathan K. Hammond · Post by **Nathan K. Hammond** » Sun Mar 30, 2008 23:21

I would attribute it to a new engine breaking in, and not worry about it much. The up and down is a little weird; did you switch something during that time? Brand or weight of oil, brand of oil filter?

nkh

Jimmy Payne · Post by **Jimmy Payne** » Mon Mar 31, 2008 08:17

Did each of the samples have close to the same amount of time on since the last oil change? If not, you are not getting a good comparison or base line.

Paul Agaliotis · Post by **Paul Agaliotis** » Mon Mar 31, 2008 08:47

Andy,
If you have a pull type starter installed, make sure the pinion is fully disengaged.
If you have a generator check that the drive cushions are still installed. If they are not there the cup will wear on the drive tang.
If you have Slick mags the impulse spring will start wearing on the coupling after about 300hrs.
Paul

ablight · Post by **ablight** » Mon Mar 31, 2008 08:51

After about 60 hours I put a can of Avblend in. The next oil change gave me the 69 value for Iron. That scared me so i did not use Avblend again. The next oil change was 22. Then the airplane sat over the winter and only flew 10 hours. The next oil analysis was the 74 value. I am using aeroshell 80 or 100 Plus now, no Avblend....Andy

ablight · Post by **ablight** » Tue Apr 01, 2008 08:18

Paul

I have all those things - Slicks, generator, pull start. What I am looking at to make sure those issues are not my problem? How do I tell if my starter is fully disengaged? Andy

Captgrumps · Post by **Captgrumps** » Tue Apr 01, 2008 12:04

Anyone have a source for the long engine mount for a Champ to mount starter and generator without modifying firewall? 7CCM (L16-B)type mount?

Doug

Paul Agaliotis · Post by **Paul Agaliotis** » Tue Apr 01, 2008 12:54

Andy,
The bracket the pull cable is attached to has a specific rigging location. This assures the clutch assembly is fully engaged before the switch powers the motor. It should be in the service manual.
A quick check will be to look for clearance between the arm and the clutch plunger. If there is none rotate the prop and see if the clutch spins if it does it is not releasing. If some gap exists pull on the plunger to see if it will move aft, if it does the clutch may not be fully released. The plunger should be kept clean and lightly oiled.
Be careful!!! If you push the little button on the top of the starter it will crank.
The generator has rubber cushions in the drive assembly. They should have been replaced at overhaul. You can try to look at the armature to see if it lags the prop rotation or try to move it. It's probable easiest to remove it.
Paul

Nathan K. Hammond · Post by **Nathan K. Hammond** » Tue Apr 01, 2008 14:19

Doug, try Buzz Wagner, or go with the smaller B&C or Sky-Tec starter and generator.

nkh

ablight · Post by **ablight** » Thu Apr 03, 2008 14:28

Had my compression checked today. 77, 77, 77, 74. Andy

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Oil Analysis

Oil Analysis

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