A

avi8tor50

Well Known Member
Hi all-

Have a Van's oil pressure gauge AND have a second transducer for my DYNON EMS. New O-320-D1A getting break-in with mineral oil. When I start the engine the DYNON EMS shows oil pressure immediately and in normal range. The Van's gauge takes 1-2 minutes to show pressure. When it does it is in the normal range and correlates with the DYNON. Any thoughts?
I did pre-oil the engine before first start and I know there IS oil pressure.
Has anyone else noticed a slow oil pressure rise for a Van's gauge? I am inclined to believe the DYNON but would like the opinions of others.
Thanks.

Peter K
9A
 
Do you have a restrictor fitting on the gauge? If so, where is it located - on the gauge itself, or near the engine?
 
How are the transducers plumbed?

i.e. one hose to a manifold with two transducers in the same location and orientation?

or

one transducer off the rear case and one off the front?

or

some other variation?


Might also be a "air in the line" issue contributing to the delay.

Different transducers? Isn't the Vans one significantly bigger?


The 1-2 minutes is the part I'm perplexed about. None of the above should cause that much of a delay....
 
Two minutes?
I have never heard of that type of time delay but try this anyway.
Remove a plug from each cyl. crack loose the oil pressure sense hose at the oil pressure sensor. Crank the engine with the starter until oil begins to leak at the loosened hose and then re tighten. Reinstall the spark plugs and re-check the gauge operation.
 
I've installed two of Van's oil pressure gauges; and they have both been immediate to show pressure.

L.Adamson --- RV6A
 
Thanks to those who replied.
The set up is both transducers for oil pressure coming off the manifold supplied by VAN'S on the firewall. One oil line supplies pressure to both transducers.
Prior to engine start I pulled the plugs and pre-oiled the engine until I had good flow from the end of the pressure hose that had been disconnected from the transducer manifold.
Both transducers are about the same size.
Restrictor fitting is at the engine.

I am perplexed as well as is my A&P/IA friend.

Peter K
9A
 
A couple more checks...

Maybe you've already done this, but also recheck each wire in the circuit with an Ohm meter for continuity. The 1-2 minutes seems flakey though... It could be a bad ground or connection, or perhaps a cracked wire. I've heard of situations with electronic oil temp gauges working erratically due to a bad engine/airframe ground strap connection, so anything is possible when it comes to electrons...:eek:
 
Joe Blank said:
Maybe you've already done this, but also recheck each wire in the circuit with an Ohm meter for continuity. The 1-2 minutes seems flakey though... It could be a bad ground or connection, or perhaps a cracked wire. I've heard of situations with electronic oil temp gauges working erratically due to a bad engine/airframe ground strap connection, so anything is possible when it comes to electrons...:eek:
Click to expand...

Since both sensors are plumbed at the same point, I agree with Joe.
The Van's sensor's ground is through the pipe threads. Check for good ground continuity between the body of the sensor and airframe ground.
 
Switch the wires. Even if the ohms are different you might see the delay move with the sensor. Sounds like you are down to 3 possibilities.

(1) ground or wire

(2) transducer

(3) gauge
 
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