Back to the shop

I've been super slammed trying to close on a new house as well as at work and had a wild business trip to Vegas.  Now that's all sorted it's time to get the plane fixed. I emailed Chris at maintenance express and he thinks there is an induction leak or blockage somewhere, a loose clamp(s) on the rubber induction tube connection boots, a loose MP hose where it attaches to the rear, curved induction tube or induction tube not bolted to its cylinder flange tightly or else some congealed oil got into the intake manifold. The last option is the one I think most likely... as it heats up it goes liquid and the engine runs just fine.  Cold and it's blocked air through the induction tube causing lower manifold pressure.  I'm going to fly it over there on Monday and get it fixed.

Manifold pressure split

Tonight I took a short flight to test out the manifold pressure split I was seeing after maintenance, and sure enough it is still there after first startup.  Here is a shot.

After a short 20 minute flight I landed and ran it up again, and it was normal again.  Hmmm, confounding!

Got her back

Today I finally picked up the plane from Maintenance Express.  Jerry flew me over in his A55 which was a big help (Thanks again Jerry!).  His plane is even faster and more powerful than mine as it has the Colemill President II conversion which uses IO550 engines instead of the 520's that mine has.

The maintenance work looks good, the main gear forks now correctly sit "over center", meaning the up lock tension is correct.  I compared visually to Jerry's very well maintained plane and they look the same now.  Also the new flight custom III tires look great.  When I hopped in the plane I was a bit puzzled because my headset mic wouldn't work on my Zulu and I couldn't contact ground control at LVK.  I have no idea what's up with that, but luckily I brought my QT Halo along and after monkeying with the audio panel for a bit, I tried the Halo and it worked fine.  I think the Zulu mic may have gone Tango Uniform... I tested my other Zulu when I got back to my hangar and it works fine... unless there is a mic mute control on the headset somewhere that I don't know about, I'll suppose I'll be sending it in to Lightspeed for repair... grrr.

When I did the run up the plane felt a bit different, it seemed to run a bit rougher than normal and at 1700 RPM there was a wide split in manifold pressure with the left engine having about 3 or 4 inches less pressure.  Also the left prop seemed to feather slower than the right one in my feather test.  I was a bit concerned at first, and I would have gone back to the shop to have them look at it, but they were closed and Chris had departed to Oshkosh in an F33A a few hours earlier.  My ride Jerry had also just departed.  I spent some time trouble shooting it and ran the engines up to full power on the ground.  At full power both engines seemed normal, and the manifold pressure, oil temp and pressure and fuel flows all looked normal.  I decided to depart and had an uneventful flight home.

Back at CCR I did another runup before shutting down and the MP split was back to normal and I didn't notice any of the roughness.  Strange!  I did notice that the left engine was low on oil on the preflight, they must have lost some during the lifter inspection and not replaced it.  I'll mention that to Chris as I feel he should have left me with full oil for the flight back.  Since the shop was closed when I picked up the plane, it would have been very inconvenient for me to hunt down oil at that point, and Chris knew I was picking up the plane after hours.  In any event, I'm wondering if the low oil caused the left prop to feather a bit differently.  I'm stabbing in the dark a bit as at this point I have no idea.  I've got oil in my hangar and will top off the engine and we'll see if it happens again next flight.
 

Tomorrow tomorrow

The plane is still not done!  Apparently one of the bolts on the nose gear assembly is stuck.  It can't be unscrewed and Chris doesn't know why.  He thinks it might be bent or else some rust is causing it to stick.  I told him to order a new bolt as I don't want a bent or rusted bolt up there and he is going to take the whole nose assembly off and knock the bolt free.   The new bolt costs $43 plus whatever overnight shipping costs.  Unbelievable, these planes are truly worth way, way less than the sum of their parts.  Chris is heading to Oshkosh on Wednesday, so I'm praying he get's this last item resolved tomorrow.  I'm also a wee bit nervous about the first flight after this maintenance, the landing gear especially.  I'll want them to swing the gear at least a dozen times or so on the jacks to make sure it's all good.  In the end though I'll feel much better about my gear forks now properly aligning over center, and also having all new bushings and brand new Goodyear flight custom III tires.  I'll also be stoked if the next oil change produces no more metal as I'll then know for sure it came from the chipped lifter.

Stuck in Mx

Well a 2 day exercise to do a cam & lifter inspection and replace my tires has spun out into two weeks.  Welcome to aviation...  to be fair I dropped the plane off last Tuesday night and they didn't start working on it until Wednesday.  First the lifter took 3 days to arrive via UPS and then today I got the message that the uplock tension wire arrived too late to install today, so they're not going to finish until Monday.  Grrrr.  Two weekends without my plane!  Frustrating.

Replaced a lifter

I've been going back and forth with Chris at Maintenance Express about the lifter issue.  Chris called TCM and they said that if the lifter has less than 10% of the face spalled, leave it be, otherwise replace it.  Chris described mine as being way less than 10%... in fact he said he wouldn't even call it "spalling".  It's basically about 10-20 pin sized holes or "pits", with the exception of the one that is chipped.  We decided to replace the chipped lifter only.  Hopefully that's where the metal came from and my next change will be clean, but given that there is the beginning of some pitting on the cam lobes, it looks like I'm not too far off from a major overhaul.

My plan is to baby the engine along and hope for the best.  I knew when I bought the plane that it had sat for a few years getting very little use, hence the very low time airframe and my incredibly "good deal".  Flying 6 hours in two years was okay for the airframe since it is corrosion proofed and was resting in a hangar, but was not so great for the engine.  This type of spalling is caused by metal corrosion due to moisture in the engine.  The best thing for an engine is to run regularly... at least once a week or so according to all the engine gurus I have spoken with about this issue.  If it's going to sit for a month or so it really should be filled with special "pickling" oil to stave off the corrosion.  Also when I eventually get the motor overhauled, I'm going to consider some kind of dehumidifier for the hangar... what the heck, electric is included!  There is a reason why all the airlines park their out of service airplanes down in Phoenix and not in Florida.

Cam & Lifter Inspection

On Tuesday night I took the plane over to Livermore to see Chris at Maintenance Express for the Cam & Lifter inspection on the left engine and also for 3 new tires and some minor landing gear squawks I got from the ABS service clinic.  Today Chris called me and let me know that he had the engine opened up and found very slight spalling on the lifters and also on the Cam lobes.  He also found one of the lifters had a slight chip in it, which is most likely the metal I found in the oil.  I was going to replace the lifters if I found this, but apparently Continental doesn't recommend replacement of the lifters as you're not supposed to mix new and used parts in the engine that way, since apparently the parts wear together.  If I had known that at first I wouldn't have even done this inspection!  So basically I just need to keep watching the oil to see if it starts to get worse and fly it until overhaul time.  Chris also found a problem with one of the valve guides on the #4 cylinder which is leading to oil blow-by.  That explains my oil consumption issue on this engine as well.  Rather than replace this cylinder, considering the CAM/Lifter issue, I'm just going to keep flying the sucker until overhaul time, hopefully in a at least a year or so.

Tires are going on next, and then I get to pay the bill!  Chris and the shop at Maintenance Express have been great to work with.  One thing I really like about them is they are responsive on email, which is key for me since I'm always at my desk but quite busy and the phone can be difficult to grab me on.  I'm hoping to have the plane back Friday.

QT Thumbs Up

It was severe clear yesterday and little wind, perfect flying weather for a weekend jaunt with zero turbulence even over the hills.  We headed down to LA for the weekend, and I filed IFR and of course they route you out of the way of all the bay area inbound traffic.  I didn't mind because it was so smooth and beautiful at sunset, and I wanted time to test out the QT Halo.  Overall it works surprisingly well.  I tried both the little rubber insert and the foam one.  The foam one seems to block more noise.  The only issue I had was that after about an hour I felt like my ear canal needed a good itch.  That might be because it was baking on the ground at about 90 degrees and so I started out sweaty. Overall the headset seems to be a good value for the money, though as of right now I think I still prefer the Zulu.  Both kids kept the Zulu's on for the whole flight though, woohoo!  Dina is going to try out the Halo on the flight back and if she likes it I'll buy another one... if not I'll get another Zulu.

In other news I finally found a new house and I'll now be only 10 minutes from the airport... yeeehaw!  That sounds great to me especially after the drive to the airport yesterday... we got stuck in the holiday weekend rush driving around in the madness, fetching the kids and getting to the airport took almost as long as the flight itself.  Also I'm really loving IFR in this plane.  The G600 coupled to the auto pilot with GPSS makes it so freakin nice.  I just love this plane!  Next week she goes in for new tires and to get a few squawks from the ABS clinic sorted out.  I decided to take it to Maintenance Express in Livermore, which is the shop where the ABS clinic was held.  They're expensive at $95 an hour, but they seem really cool and knowledgeable, and more importantly they seem to work quickly and efficiently.  I've learned the hard way it's tough to judge the relative cost of a shop based on their hourly rate.  If they take twice as long to do things then their hourly rate doesn't mean much.  Here is my squawk list:

Tighten RT flap actuator bolt
Service airframe hinges
Left engine lifter/ cam inspection
Rig landing gear this includes all of the landing gear rigging
adjustment listed on the squawk sheet
Service Shimmy dampener with 5606
Hydraulic Fluid
replace nose gear steering yoke bushing
replace nose gear idler arm bushing
Replace aft nose gear attachment bearing
Replace all three tires, service wheel bearings, and balance wheelassembly
Nose Tire FCIII
2 Main Tires, Goodyear FC III

We'll see how it goes.