June 2005-
Q: I am thinking of buying a 1959 PA-24-180 and am interested in knowing of any maintenance issues of which I need to be aware. The airplane is current with all ADs.
A: We checked with Mark Rieger, an A&P since 1976 and an IA since 1985, and this is what he had to say:
“I cannot think of anything on a Comanche 180 that would be an issue other than the normal items that you’d look for on any pre-purchase inspection. I’d be sure that ALL the ADs were complied with and are current.
“But having a pre-buy inspection accomplished by a competent mechanic is key before making a purchase. Definitely inspect the interior of the wings and tail for corrosion.
An engine compression check is a must, and a gear retraction on jacks where the gear can be inspected for wear would be pretty important. Excessive wear in the gear can run the price of an annual inspection to a pretty high price.
“Just a good general pre-purchase inspection of the entire aircraft and engine—and a careful review of the logbook—can sometimes save the buyer a lot of money, and alert you to would-be future expensive repairs. The money spent on a pre-purchase inspection is some of the best money you can spend.
“You may even want to change the oil filter and do a cut open and inspection of the old filter—it just depends on how much you want to know about the plane you are thinking of buying.
“Again, a competent mechanic will know what to look for; but he is also limited by what the would-be buyer is willing to spend for a look-over.”
Q: I have a Continental TSIO-360E on a Seneca II. I had the cylinders rebuilt. For some reason I am having oil siphoning out of my oil dipstick. It gets worse when I have the cowl flaps closed, in flight. What may be the cause of this?
A: You definitely have a crankcase pressure problem.
We checked with Teledyne Continental and this is what they had to say: “A mechanic needs to check for that probable cause by using TCM Service Bulletin M89-9 ‘Excessive Crankcase Pressures.’”
“If the pressures are high, proceed with an inspection of the crankshaft nose seal at the front of the engine where the crankshaft comes out of the case and bolts to the propeller. If that does not appear to be a problem then your mechanic should verify the cylinder compression values and oil consumption rates are within the standards set forth in TCM Service Bulletin SB03-3.”
We also checked with Superior Air Parts and they said to first check the filler cap. There is a seal in the filler cap that can go bad and let air leak into the crankcase. Sometimes it’s just that easy of a fix. Get a new seal and tighten the filler cap. They also said that it may be one of the crankcase seals that may need to be replaced. (Thank you TCM and Superior Air Parts for assisting with this member’s question).
Q: I have a Lycoming engine and when I pull the mixture cut-off, it continues to run for quite a while before finally shutting down. What could be causing this?
A: You did not indicate whether it was fuel-injected or carbureted.
We checked with Lycoming Engines and here is a list of possible causes for fuel injected and carbureted engines: 1) Improper rigging of mixture control linkage; 2) Mixture control valve is scored or not seating properly, or “O” ring on mixture jet is broken or deformed; 3) Vapor in lines; 4) Dirt is in the air bleed hole of fuel injector nozzle; 5) Fuel jet in nozzles is improperly located; 6) Valve in flow divider is sticking.
