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Ditto, Noel. I burst my first oil cooler the same way. I use the Kavlico O/P sender now. Previously I had a VDO. Clean-up was a pain.

pappas wrote:Ditto, Noel. I burst my first oil cooler the same way. I use the Kavlico O/P sender now. Previously I had a VDO. Clean-up was a pain.

Which Kavlico part number did you buy? Is it a direct replacement for the the VDO? Is the setup of your EFIS/engine monitor the same? How many engine hours do you have using that unit? Any problems?

Just to chime in on high oil pressure issue, I too had well over 100 lbs pressure in the first 10--15 hrs. my bottom mounted cooler is an after market, double size, racing cooler rated tor something like 300 psi. the rear pressure regulator was indeed the problem, and final fix was to shorten the stock spring one coil, and to put spring centering plug on the on the bottom of the piston to keep the upper end of the spring from rubbing on the bore, and creating particles inside the bore. this has worked 100%, cold pressure 70-75, hot pressure 60 to 65. No leaks on the engine either! tt now 57+ hrs.

Hi Guys,

I was out this morning doing some stop and goes to check some wheel maintenance I did yesterday. Every thing there works fine.
However, on my third takeoff the oil pressure went to 85 P.S.I. and stayed there. That is 15 PSI higher than normal. I could reduce the pressure some by reducing throttle but on climb out I didn't want to pull it back too far. When I landed the pressure dropped to 35 P.S.I. That's lower than normal. Both of these conditions together makes me wonder if the oil control valve is sticking some. I seem to remember that some guys polish a little off the plunger to eliminate sticking.

Question: For those that have polished the plunger, what did you "polish" it with?

Thanks for Your Time,

Wes

Maroon Scotch Brite pad by hand.

Hi Bill,

Was your plunger sticking and polishing it fixed the problem? Can you give me an idea of how long you worked on it with the Maroon Scotch Brite pad?

Thanks,

Wes

Don’t forget to check the sender to see if your readings are real. The standard VDO sender maxes out at around 80 PSI equivalent depending on the calibration curve in your EFIS. If you are seeing readings significantly higher than that it is likely that your sender is bad. If you are seeing consistent readings around 80 psi it likely means you actually have oil pressure much higher than that. A few pieces of tubing and a cheap oil pressure gage from any auto parts store will confirm if what you are seeing in your display is real or not. Before you start tearing into an engine check the sender first especially if the engine was operating normally for a time period before getting unusual oil pressure readings.

Wes -See kmacht’s post above.

As for polishing: Maroon scotchbrite is what I used. I lightly polished the sides of the plunger, and then I paid special attention to the corners/chamfers around the top and bottom of the plunger. I wanted to make sure there wasn’t an edge that could catch or dig into the bore as it slid up & down.

—Noel

P.S. Because my plunger jammed in the bore after the initial engine run, I also made a sanding rod by wrapping some 600-grit sandpaper around a wooden dowel that was approximately the same size as the plunger. I worked that up and down the bore and tried to abrade evenly all around the circumference of the bore to slightly widen and smooth it out. Then I used rubbing alcohol in a squirt bottle to gently flush the particulates out of the bore, followed by a low-lint cloth to clean it out. Be careful not to use anything that might shred or leave lint or materials that could clog the oil galleries!

kmacht wrote:Don’t forget to check the sender to see if your readings are real. The standard VDO sender maxes out at around 80 PSI equivalent depending on the calibration curve in your EFIS. If you are seeing readings significantly higher than that it is likely that your sender is bad. If you are seeing consistent readings around 80 psi it likely means you actually have oil pressure much higher than that. A few pieces of tubing and a cheap oil pressure gage from any auto parts store will confirm if what you are seeing in your display is real or not. Before you start tearing into an engine check the sender first especially if the engine was operating normally for a time period before getting unusual oil pressure readings.

If I'm not mistaken theVDO 80 psi sender should have 5 Bar stamped on it the 150 psi would be 10 Bar. The Hummel engines come with the 150 psi senders.

Hi Guys,

Thanks for the replies.

wlarson861 wrote:Maroon Scotch Brite pad by hand.

OK, Maroon Scotch Brite it is.

kmacht wrote:Don’t forget to check the sender to see if your readings are real.

I did reduce power a little during climb out and the reading dropped slightly. So, it seems I was still in the active range of the sensor.

NWade wrote:As for polishing: Maroon scotchbrite is what I used. I lightly polished the sides of the plunger, and then I paid special attention to the corners/chamfers around the top and bottom of the plunger. I wanted to make sure there wasn’t an edge that could catch or dig into the bore as it slid up & down.

OK, that's what I'll try.

Mike53 wrote:If I'm not mistaken theVDO 80 psi sender should have 5 Bar stamped on it the 150 psi would be 10 Bar. The Hummel engines come with the 150 psi senders.

I'll check the sender. I'm thinking mine came from GRT with the EIS. I did buy a second one from them to verify the original. One read slightly higher than the original but was close.

This is an intermittent problem. It's acted up some in the past but it was more pronounced this time. Sure seems like a little "sticktion" of the plunger is likely.

Thanks Again, We'll See,

Wes