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Permalink Reply by Shay King on April 6, 2017 at 12:00pm

Had a similar problem to this a few years ago with erratic oil pressure indications, not as high as yours though. The solution was to change the small spherical ball bearing in the oil pressure relief valve to the new style mushroom shaped relief widget. The 912 forum on www.rotax-owner.com would be a good place to get more info about this issue.

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Permalink Reply by Bob Pustell on April 6, 2017 at 3:29pm

I would suggest the simple things first. Since you mention a sender I presume you have an electric pressure gage of some type. To eliminate indication system errors I would suggest temporarily installing a simple mechanical oil pressure gage. You can buy a cheap one at an auto parts store as a test item. It should come with the gage, some type of mounting bracket, some flexible tube to run to the engine from the gage and a fitting to screw into the engine and attach the flex line to.

By installing a direct reading mechanical gage you eliminate all the other variables. It the gage reads the same high pressure you know it's real. If it reads normal pressure you know something is wrong in the fancy electrical stuff rather than in you engine's oil pumping system.

If putting a direct reading mechanical gage in as a permanent installation, do not use a cheapo gage but for a temporary trouble shooting installation a cheapo will do the job.

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Permalink Reply by Raymond Paul on April 7, 2017 at 5:13am

Hi Andre I have seen this problem on 3 912 motors here in Zimbabwe. All motors were checked with a cheap mechanical oil pressure gauge and all motors checked out perfectly.

Replaced the electric sender oil pressure unit (VDO) and all pressures returned to normal readings on the instrument panel gauges.

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Permalink Reply by Andre Zeman on April 7, 2017 at 5:18am

Thank you all for replies. I have ordered the VDO sensor and mechanical oil pressure gauge. I will check the oil pressure and if normal I will replace the VDO sensor. I will keep you posted. 

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Permalink Reply by Andre Zeman on April 7, 2017 at 6:09am

How do you apply proper torque to the VDO sensor. I have torque wrench that takes sockets. Do I need spanner type of torque wrench? Also the rotax-owner video about this is calling for Locktite 243. Difficult to find here. Can I use this?

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