Engine overhaul time - Lycoming IO-360-M1A

[Rich]

Annual last week. I discovered that all 4 governor nuts needed to be re-torqued (aka “snugged up”). 40 hours since installation last December.

[mhoran]

It's possible, but I know James, the owner of the overhaul shop, is very careful about proper torque. I don't think my torque wrench can get in there, so I'll have to have someone take a look regardless. Sensenich Prop Services overhauled the governor and they have another location by the Lancaster, PA airport, so maybe I can have them take a look.

[Rich]

It's possible, but I know James, the owner of the overhaul shop, is very careful about proper torque. I don't think my torque wrench can get in there, so I'll have to have someone take a look regardless. Sensenich Prop Services overhauled the governor and they have another location by the Lancaster, PA airport, so maybe I can have them take a look.

You can’t get a torque wrench on all the nuts. I just put a 1/2 wrench on each and it’s obvious they didn’t retain proper torque, as I had checked them at installation.

I wonder if it’s possible the studs work a bit loose in the engine case?

[mhoran]

That was my thought but James didn't think it was likely.

[mhoran]

I managed to tighten down the nuts a bit. They were pretty tight, but I got a bit of a turn on all of them. I cleaned the engine and the cowlings and went for three laps around the pattern. There was some oil around the governor and on the cowlings afterwards, but nothing as bad as before. It could have just been residual. No more oil after another ground run. I don't want to get my hopes up though, as we've thought this was resolved before.

If this doesn't resolve, sounds like I may need to replace the governor entirely. Also, I no longer get 2700 RPM. I've verified that the control arm hits the stop and the cable seems to be adjusted properly. But if it doesn't leak I will probably just live with it. Static RPM is about 2600 and max RPM is about 2650.

[Lance Murray]

You said they used "gasket maker" on the governor. Can you expand on this? Could this be interfering with obtaining proper torque?

[mhoran]

Yeah, I was wondering about that. All I know is they put something (maybe Permatex?) on the gasket before installing the second replacement gasket. I don't know if they did that this time, and I don't know if Angel City Flyers used gasket maker on the first replacement, which also leaked.

[mhoran]

Unfortunately still leaking. So the governor will come off and go back to Sensenich. Jim at Take Flight thinks the adapter plate may have been damaged somehow. I checked some photos and it was clearly replaced. Hopefully Sensenich will honor the warranty and I won't have to buy a new governor.

[mhoran]

Turns out the adapter plate is warped. Not sure if it's been like this or if it keeps warping. Hopefully it can be replaced without needing a new governor -- and doesn't warp again.

[Charles]

As an update on my own overhaul, the engine runs great but cyl. #4 still runs 40F hotter than the other 3 which are all within a few degrees of each other. If it weren't for that issue, I would say it performs like a new engine. But that issue is impossible to ignore, with the CHT of that cylinder often in the 410-425F range

The shop has so far ruled out induction leaks and cooling baffles and they swapped the CHT sensor, spark plugs, injector, etc. with another cylinder. To say they are puzzled would be an understatement. It's a little frustrating and their calls to Lycoming have not done anything to improve that. Lycoming says the cylinder is good to 480F so those temps should not be a cause for concern and the cylinder may need up to 100 hrs. to settle. It's only at about 40 hrs. right now, and the shop is happy to leave it at that until I reach 100 hrs., and they say I should just fly normally and ignore it for now.

I welcome all suggestions at this point.