To Overhaul or Not Overhaul

[OR75]

This may already have been addressed (please re-route me to the relevant thread if it is the case): 

My J's IO-360-A3B6D is getting close to TBO (~1850) . It was factory rebuilt in 1995 and has been operating flawlessly. Compressions are in the 76 - 78 range for all 4 cylinders. UOA is normal and I consider oil consumption as low. The engine has been reliable, including those hot starts !!

Questions I have >>>

What shall I do ? keep running past TBO if the engine still runs well ? field O/H ? .... ?

Do insurers "worry" if an engine is past TBO (policy premuim for engines past TBO) ? Do I risk a denied claim if something happens and the engine is past TBO.  

Thanks for the input.

 

[jetdriven]

Check Mike Busch's info on the web. 

 

Basically, an engine is airworthy if it conforms to its type certificate.  IF it is not making metal, makes rated power, and has no large deficiencies (cracked case, oil leak, etc)  then fly that engine until it gives symptoms of needing overhauled.  Within reason of course, perhaps 4000 SMOH is a lot.   Insurance companies do not care as long as it passes annual.  It is either airworthy or not. a TBO number is a number from the manufacturer. It is not mandatory.

[KSMooniac]

Keep flying it!  Wait until you get some definitive signs that it needs to be overhauled, such as abnormal metal in the filter or worrisome readings in the oil analysis.

[fantom]

TBO time is about as meaningful as a SB. It's just a suggestion to watch it, and a guide for folks who don't know much about their plane.

Your engine will tell you when it wants you to spend a lot of money.

[skyking]

I am with the group on this one.

I had an engine make it to almost 3000 hours once. As long as it passes the annual for compression etc i say fly it.

Fantom put it best...the engine will tell you when its time to empty out the ol' wallet.

[N33GG]

With an aging engine, also keep an eye on the oil pressure, especially in hot weather.  If oil pressure stays good and oil analysis is OK, I would fly it until you hear "Houston, we have a problem".  It's no guaranty that you won't have a problem in flight, but you can have a problem in flight with a low time engine as well.

Sounds like your engine is doing great.

[Parker_Woodruff]

Sounds like you need to keep flying it.  I'd establish a trend with oil analysis at Blackstone if you aren't doing that already.

I had a 180hp Cessna 172 that me and my friend flew through something like 2500 SMOH in 4 years (over 3000 hobbs hours!).  That was a 3rd run on that engine I believe.  The lowest compression was something like 77/80 and all I did was replace rings right around the time I sold it.  The current owner has still been flying it on the engine I sold the plane with.

[Cruiser]

I traded the original engine on my '84J on a FREM when it had 6200 TT and 2200 SMOH. It had already had two overhauls both going to 2000 hrs.

Although it was still performing well and the oil analysis was good, the case was leaking (fretting?) and it had a noticeably different sound when working hard in a climb. Maybe, if I had more exerience with that engine (I just purchased it) I would have run it longer.

Finally, I was concerned that if something catastrophic occurred, the engine would have no trade-in value with the factory.

[Seth]

As many have said - keep flying it.  As long as it's not making metal, compressions are good, and you don't sense it is going to fail - keep flying it.  If you get more and more worried, and just stop trusting it, even if it is still performing well, that becomes a dilemma.  I'd keep flying it until it burns a lof of oil, has low compressions, develops oil leaks, etc . . . It will be time to complete the overhaul at some point, but that some point may be years from now and hundreds of happy flying hours later.

-Seth

[flyboy0681]

Quote: fantom

Your engine will tell you when it wants you to spend a lot of money.

[John Pleisse]

Sure...keep flying it, but be realistic. Clogged nozzles, sticking valves, skipping-long starting mags, unbalanced prop, sloppy fuel injector servo, heavy oil consumption....all should be taken seriously and point to bigger issues. Don't let a mature engine nickel and dime you to death. I would carefully triangulate evaluation of dollars spent on ....an aging engine vs. prudent safety vs. dollars toward an OH.....from here on out.

[Mooneymite]

Keep flying it, but keep watching it, too.

You don't want to get into a condition where the engine, not you, decides when it's overhaul time!

Once you have a fresh overhaul, reman, or new engine.....then you REALLY have to watch it.

 

[N33GG]

Quote: Mooneymite

Once you have a fresh overhaul, reman, or new engine.....then you REALLY have to watch it.

 

[OR75]

Thank you all for the input.

Any thoughts on how insurance companies ses it ?

They ask every year about engine hours. 

[danb35]

I've never been asked about engine hours on my insurance renewal.  I've been asked about my hours, but nothing about my plane, except when I was initially insuring it, to establish the value.

[Piloto]

You already have an engine that has proven itself. When you overhaul you are a taking a minor risk that the new engine may have a problem. Also a new engine may be subject to a new ad that would not have applied to the old engine. Keep it running until you see engine wear signs like low oil pressure in idle, low compression, oil filter deposits and high oil consumption.  

[KSMooniac]

The two insurance companies I've used in the past have never asked about engine hours either, just hull value.

[201er]

Do you report the overhaul to the insurance company to increase hull value by the newly overhauled engine?

[KSMooniac]

I haven't overhauled my engine (yet) but have made other improvements over the almost 5 years I've owned my J.  In my case, I raised the hull value after some improvements, or left it the same even as I've flown 100-150 hours per year which of course reduces the value somewhat.  If I were to overhaul today, I would probably bump my hull value up by $10k or so at my next renewal.  I've already done paint, dual WAAS upgrade, GTX-330ES xponder, Wilmar tank job, MT prop, plus a few speed mods.  My hull value is close to what it might cost me to buy another similar Mooney and bring it up to what I have now.

You need to chose your hull value somewhat intelligently... enough to replace your plane in the event of a total loss, but not so much (ie over-insured) that the insurance company would feel compelled to repair what should be a total back into a flyable airplane.  (as an extreme example, insuring a $50k market value E or F to $100k such that a company might spend $50k in repairs after a loss, leaving you with a severe damage history)

[fantom]

The constant challenge of equalizing upgrades with depreciation 

[KSMooniac]

Sooner or later upgrades start adding to the hull value, right????  ;-)

[jelswick]

Seeing the few notes on the risk with new or newly overhauled engines on here is interesting in the timing of them.  If  you look at AOPA's Real Pilot Stories story they just added on their home page, it's someone that had engine issues/emergency on a recently overhauled engine while in IMC.

[John Pleisse]

I've had two...one Firewall Forward, the other factory new. Never an issue with a new or recently overhauled engine. Likewise, for several years, there were 4 Mooney 201's tied down next to me at my then home base. 3 were overhauled in addition to mine. 1 Mattituck, 1 Zephyr and 1 Factory. Nobody had an issue. A Lycoming engine past 50 hours/oil consumption is the safest piston you can fly.