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- Apr 2, 2018
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Hi! Were looking for any ideas to help us investigate high oil temperatures on our new (to us) 1979 Dakota. Heres what weve seen and what weve done:
We purchased the airplane in early June after a combined pre-buy and annual. The inspections noted 27 items, most of them minor (i.e. missing safety wires, zip ties instead of clamps). We fixed most things and saved several items for future upgrades/inspection. Everything else indicated a strong well-running engine. We arranged to pick up the airplane on 07/05. On our first flight (with a CFII), we noticed oil temps at redline just after climb-out and levelling at ~3000. We immediately returned to the airport and taxied to maintenance. Everyone assured us that this was the first time they had seen high oil temps and it had been in the normal range on all previous flights. Over the next 24 hours, the A&P changed the vernatherm (test flight), oil cooler (test flight), changed from Phillips 20w-50 to Aeroshell W100 plus (filter inspected and looked clean) and reamed vernatherm seat (test flight). Nothing worked. We are now waiting for a new accessory case to ensure the vernatherm seat isnt flawed or damaged. We have a ~2 month wait to see if that fixes things. I suspect it wont. Other things that have been mentioned, and checked, include hoses, winterization plate, and baffles. The avionics include a JPI EDM 700. After some delay, we purchased the proprietary cable and downloaded the data. The attached plot show flights before the annual, the flights in red are on 07/05-06. It appears this issue is in fact a new problem.
Both the original temp gauge and the EDM agree on temperature increase and redline values, oil pressure decreases as indicated temperature increases. Outside air temperatures ranged from ~60 F - ~85 F during the test flights on 07/05-06. EGTs and CHTs all were in normal range see attached plots.
Everyone weve been dealing with from the CFII, the A&P, and the seller have been great and are trying to solve the problem, but I think theyre running out of ideas. Any help would be greatly appreciated.
Thanks!
We purchased the airplane in early June after a combined pre-buy and annual. The inspections noted 27 items, most of them minor (i.e. missing safety wires, zip ties instead of clamps). We fixed most things and saved several items for future upgrades/inspection. Everything else indicated a strong well-running engine. We arranged to pick up the airplane on 07/05. On our first flight (with a CFII), we noticed oil temps at redline just after climb-out and levelling at ~3000. We immediately returned to the airport and taxied to maintenance. Everyone assured us that this was the first time they had seen high oil temps and it had been in the normal range on all previous flights. Over the next 24 hours, the A&P changed the vernatherm (test flight), oil cooler (test flight), changed from Phillips 20w-50 to Aeroshell W100 plus (filter inspected and looked clean) and reamed vernatherm seat (test flight). Nothing worked. We are now waiting for a new accessory case to ensure the vernatherm seat isnt flawed or damaged. We have a ~2 month wait to see if that fixes things. I suspect it wont. Other things that have been mentioned, and checked, include hoses, winterization plate, and baffles. The avionics include a JPI EDM 700. After some delay, we purchased the proprietary cable and downloaded the data. The attached plot show flights before the annual, the flights in red are on 07/05-06. It appears this issue is in fact a new problem.
Both the original temp gauge and the EDM agree on temperature increase and redline values, oil pressure decreases as indicated temperature increases. Outside air temperatures ranged from ~60 F - ~85 F during the test flights on 07/05-06. EGTs and CHTs all were in normal range see attached plots.
Everyone weve been dealing with from the CFII, the A&P, and the seller have been great and are trying to solve the problem, but I think theyre running out of ideas. Any help would be greatly appreciated.
Thanks!
