Oil Pressure too high

[Geo]

Hello.
2009 RV7A, 250hrs on Mattituck IO360, 250hrs TTSN.
Recently my oil pressure has been running too high, as indicated by my EIS4000 engine monitor.
The norm was 85-90 psi on takeoff, then as oil warmed up it would settle in the upper 70's at cruise.
Now it reads 97-98 on takeoff, even if i let the oil get warm before i take off. and even if i pull back at low MP, it stays 94-95.
I run Aeroshell 15W50 (but, again, this high pressure seems unrelated to oil temp), current oil/filter set has 15 hrs on it.
Before I go through with oil, filter change and transducer replacement, I want to show a picture of the oil pressure relief valve I took last night.
(Please note that I have never touched it so far).
If I put a wrench to the locknut I can easily turn it clockwise (without taking the locking pin out), so easily that I can almost do it by hand. It does not turn counterclockwise (it seems bottomed-out).
Is this normal? Do you have any suggestions?
Thanks.

[DanH]

Originally Posted by Geo

Do you have any suggestions?

Yes, check the oil pressure sender before assuming an engine problem. In my experience, instrument error is more common than actual malfunction.

[Ironflight]

I am with Dan on this - that is a very common failure description for VDO oil pressure transducers - I've seen it multiple times.

Paul

[RKellogg]

Does oil pressure indicator show zero when engine is not running? Some sensor failures create a zero offset error, too.

I think there is supposed to be safety wire though that roll pin...

[Yen]

I had this problem and it was caused by a poor connection. Check the connection at the sender and also at the instrument, also earths. Mine was a poor connection at the instrument, but it is easier to go to the sender first and hope you don't have to scrabble at the back of the panel.

[Doug]

I just joined the club of VDO oil pressure sender failures (GRT EIS4000). Cruise OP was sliding between 86 and 97psi with no correllation with any other engine parameter. Replaced the sender, now rock solid between 79 and 81 psi again in cruise. 226 hours O-320

[erich weaver]

Originally Posted by RKellogg

Does oil pressure indicator show zero when engine is not running?

this is definitely worth checking. My sensor from GRT did not indicate zero when engine was off. I asked GRT about it and their hi-tech suggestion was to tap on the sensor with your finger a few times. Voila! All fixed.

[Geo]

It was a bad electrical connection between the sender body and the (grounded) manifold.
After cleaning it up, pressure is now normal again.
Thank you all for the advice.
I'm still puzzled by that pressure relief valve, though.....
;-)

[HIIFLY]

I want to show a picture of the oil pressure relief valve I took last night.
(Please note that I have never touched it so far).
If I put a wrench to the locknut I can easily turn it clockwise (without taking the locking pin out), so easily that I can almost do it by hand. It does not turn counterclockwise (it seems bottomed-out).
Is this normal? Do you have any suggestions?
Thanks.[/quote]

If I understand your statement above , the castle nut on the threaded shaft of the pressure relief valve screws away from the roll / lock pin , then when reversed screws back and stops when it is against the roll pin ? If this the case then the adjustment castle nut is Not installed properly . The Castle nut should be locked to the threaded shaft when the roll pin is installed , this is so when you turn the "Nut" the threaded "Shaft " turns and screws in and out to adjust the spring and Ball pressure inside the unit . Raising or lowering the oil pressure . Other type units that do not have this nut and shaft use washers to shim the spring tension up and down . PS I run safety wire thru the hole in the roll pin and tie it off so the shaft can't turn and change the pressure , just in case ???
I hope this helps .

[Antoine.S]

For some mouths i've observed an elevation of the standard in flight oil pressure
at the same operating temperature. about 2-3psi..
was seeing 79-82, now 83-86..

I got the van's series oil pressure gauge/sender. IEVOP100 & IE 411K
and the plane/motor is 220h TT.

After reading your thread, i made some investigations..
i've clean all contacts but still the same.

it look like i got the zero offset problem..

Cold motor, don't run since a week (no residual pressure),
master switch on:

Oil pressure needle goes up 2mm over the 0psi stop pin. (around 1.5psi-2psi)
it seem's to be the same gap that indicate 85psi instead of 81psi in flight.

When the I.E 411K sender is unscrew of the oil line, breathing free,
same indication..
When i disconnect the lead off the sender, the oil pressure needle goes back to the zero stop pin.

I've check the resistance of my lead wire and it is normal.
I've check the resistance of the sender and it is 231.5ohm..
i've read It should be 240ohm at 0psi, 33.5ohm at 100psi.

The 8.5ohm delta between 231.5ohm & 240ohm can be significant to induce this little error in my opinion.
So y guess it is the problem. the delta is may be the same on all the range..

Do you think i'm right?

Is somebody can ohm test a working sender (showing a real 0psi)
to give us a reference?

it seem's that the I.E.411K is the same than stewart warner 201359.
(read on VAF)
mine look exactly the same than this one.
http://i.ebayimg.com/00/s/MTIwMFgxNjAw/z/3ZMAAOSwnDxUc4y2/$_35.JPG