There was recently a post on the FB Seneca group which incidentally talked about time in between overhaul for the turbos. My Seneca V turbos (in use on my TSIO360RB1B and LTSIO360RB1B engines), were last overhauled around 650 hours ago. There was some mention to expect OH around 700-800 hours.
Anyone have experience with turbos on a Seneca V (ie. the engines above) needing to be overhauled around that time frame...or....longer?
Also, what to watch for to indicate it's time for the overhaul. It was mentioned degradation of performance at altitude, but I'd like to know more.
I received this very useful reply back from Gary Main regarding time between overhauls for Turbos. This suggests something "better" than the 700-800 hours we've seen bandied about.
Brad, The turbocharger is rated to the TBO of the engine. We find that a good time to start thinking about overhaul is 1000 -1100 hours because the bearing housing to turbine housing relationship starts to degrade. I have enclosed a little maintenance tip that helps explain this and you can keep an eye on it. Just have your mechanic look at this area specifically at annual inspections in addition to the normal inspections called out for in the maintenance manual.
The cost range for this units will be between $5500 and $7800 in 2025. Hartzell has raised the price on the parts for these units quite a bit in the last few years. The turn time for overhaul is running about a week.
Sincerely, Gary Main Main Turbo Systems Inc. FAA Approved Repair Station# MAMR190K Certificate No: EASA.145.6274 (800) 847-8815 or (559) 635-3322 www.mainturbo.com
We just replaced a turbo this week after what appears to be 1600 hour of service. By the logbooks, it was part of the original overhauled engine when installed.
We just happened to speak with Gary Main also in our review process. Boy he was professional, helpful, and knowledgeable. Price from Air Power was ~$8,100, with $650 core charge. Took 5 days. Gary's shop did not have any avail at the time, but he said they generally have a few on the shelf ready.
We started to feel asymmetrical thrust on takeoff requiring a slight need for heavy right-steering (and even a shameful toe-tap breaking) on takeoff for the first ~200 feet. However, the MP gauge did not display a difference on takeoff, although with eyes on runway it could be difficult to catch a temporary lag, maybe.
We then noticed the turbo ran out of breath at 10,500, (29' MP) while the other engine was still ready and able to produce much more.
We inspected, and although likely an inexact science, the turbine blades/rotor would rotate with the push of a finger, but it took effort and stopped immediately when not being pushed. That is, it did not free-spin at al, zip.
All that data combined, we just fully replaced and thanked it for its many hours of service.
