Does anyone here have any experience with a Piper Apache with the 180 hp Geronimo conversion? Im asking for a friend on mine who has one that is in for annual right now. The engines are about 12-1300 hours SOH and just seem to be blowing an excessive amount of oil out the breather tube. Engines seem to burn about a quart of oil every 5 hours or so and oil gets dirty fairly quickly...within 10-12 hours. One of the engines has started "backfiring" quite a bit at lower power settings...ie on the ground. Also, I guess her spark plugs were extremely dirty. The mechanic just told her "she needs to lean more". Ive seen her lean...she can't lean anymore. The mechanic also told her not to worry about the excessive oil blow by and dirty oil because "those engines just do that". I believe they are O-360's. To me, with my limited knowledge of piston engines, it seems like there is some serious excessive blow by happening. Could that be causing the fouled plugs and backfiring? The mechanic said the compression were "fine". I feel like I've read that doing compression checks on a cold engine vs one that has just been running can lead to different results. Is that true?

I sure appreciate any input you could give me that I could pass along to her!

Merry Christmas!

The Geronimo has the Lycoming 360's

Thanks Arlen...I couldn't remember! I will edit!

He's absolutely right "those" engines do. I don't think that is a trait of an 0-360 though.

What is the N number? I flew 2 different Geronimos part time for a mapping company lots of years ago. Saw one of them recently at the Mt. Pocono airport.

My O-360 (about 1450 SMOH) uses a half quart every 25 hours. Very little blow-by. I would suggest a second opinion on your friend's engines.

While I don't have experience with the PA23, I do have a 360 in my Cherokee. From my experience the consumption does seem high on your friend's engines I have no oil coming out the breather tube.

The anomaly/clue is that the issues are with both engines.

Diamond aire (look for them on internet) seem to be the ones most familiar with Geronimos. I like Geronimos, but never flown one.

Rgs,

Patrick

I have a couple hundred hours riding in the back seat of a Geronimo with my sister, some coloring books and a deck of cards. I still remember my dad cranking that trim on the ceiling. N711NL. I wonder whatever happened to that plane.

Jeff,

Its 4143P. Based in Sarasota. SRQ.

After every flight, oil is literally dripping off the gear doors!!

Thats kinda what I'm thinking too Russ!

Does your friend fill the missing oil back to the full line everytime?
The aztec I fly likes its oil on 9, if I put an additional quart up to 10 it throws it overboard. Maybe he/she needs to find the sweet spot........ But a second opinion would be of great value.

I would get the plane out of annual and get a second opinion. Blow by from the rings into the crank case can cause the engine to use oil and turn the oil black. I do not like to hear backfiring in a engine. It is a sign something is not right.

Thanks Steve. I'm going to recommend that she does. I just hope she listens!