RV-12 No Oil Pressure during purge

[Walt Shipley]

Today I hooked up a pressure regulator per instructions in the Rotax SI bulletin to purge my Rotax engine. After some aerobic exercise turning the prop, I was unable to make the oil pressure gage move off zero.

On glancing through the FlightDek D180 installation manual, it appears that
I will need to enter parameters for the various engine instruments, oil pressure gage included. Is this correct?

Initially I was under the impression that all I had to do with the D180 was basically turn it on, but maybe not.

Walt Shipley

 

[Dave12]

Walt, make sure that the master and avionics switches are on. The D180 can be powered up without them on and I don't think you will get a reading without them being on. I can get 50+ lbs. pulling the prop through (no spark plugs of course). You might want to check it with a mechanical gauge as it would not be unforeseen for the Honeywell sending unit to be defective. If you have used the relocation kit, try bleeding the oil line. If you don't have it, strongly consider it. Good luck

 

[Walt Shipley]

Dave, both the master and avionics switches were on. Dumb question: what is a "relocation kit?" Haven't heard of that before.

Walt

 

[Dave12]

Relocation kit

It is available from Lockwood Aviation and it includes all the parts to move the oil pressure sender from the front of the motor to the firewall. It takes the sender away from the vibration and heat. You will have rock-solid readings instead of the fluctuations many have experienced. It think it will make the Honeywell sender last longer (hopefully). My sender lasted exactly 50 hours, fuel pressure lasted 65 hours.

 

[Jetguy]

If only it was that easy!

On glancing through the FlightDek D180 installation manual, it appears that I will need to enter parameters for the various engine instruments, oil pressure gage included. Is this correct?

Ohh so sorry. but no you dont need to do this assuming you are going E-LSA and bought your D-180 from Vans. All the parameters are pre-set and some cannot be changed per Vans request to Dynon. This is called locked settings. In section 6 you don't need to do,
Alarm & Color Threshold Config
Global Para Setup
Engine Type Config
Flaps Cal
Tachometer
Manifold Press
Oil Press
Oil Temp
EGT
CHT
Fuel Press
Fuel Level
Voltage
Current
Gen Purpose Inputs
Contacts
General Pur Therm
These should all be preset.
Dont worry about relocating your Oil pressure sensor at this point just concentrate on getting everything up and running for now then later we can talk about the relocation thing.

Initially I was under the impression that all I had to do with the D180 was basically turn it on, but maybe not.

I thought that about a Windows PC to. No Im sorry. First off the manual stinks and its like you are reading another language. When you first turn on the D-180 you will need to run the DSAB. See Chapter 7. This procedure lets the D180 find all the other components in the system, kind of like plug and play on a computer. Such components would be the AHARS(compass you put on the top of the tail-boom) in the tail, the Outside Temp Probe, Servos if you have an Autopilot, the A/P control head if you have one, the EMS(Engine Monitor System), etc. After you do this you will see a list of all the components, make sure everything is found.(see PG 7-6 for an example) Remember the list can go on to page 2 when looking at the display. If everything is not found you have a problem. Next you need to do a compass calibration. (see PG 5-2). Then you need to do fuel calibration. (see PG 6-5, confusing as all getout) Then you need to do Trim calibration. (see PG 6-6) You have 50% chance to get it going backwards. My trim Tab moved in the correct direction but it was displayed backwards on the D-180. Next if you have an Autopilot then you will need to set that up.(see Section 8) Also fuel flow will need a Kfactor number.(see PG6-14) Thats all I think for for now. Good luck!

PS think about joining this web site. http://www.rotax-owner.com/ They have some great videos on the Rotax engine, there is one on oil purging.

 

[Walt Shipley]

Dave & JOhn, many thanks for your input to my problem. I want you to know I really appreciate your help.

I'll be following up on your suggestions, and hopefully I'l be able to work through this.

Walt

P.S. John I'm already on the Rotax Owner's group. It's a great help.

 

[KALEWIS]

Our experience :

Purged oil system as described in Rotax service bulletin. Disconnected "in" line and capped. The "in" line was left in place near the oil tank and we attached a longer hose to drain in excess oil out from that line. Pressurized the tank and removed plugs, handcranked and saw oil psi hit 55 in the green. Cranked the engine via the starter and pressure held steady at 60-62. However, no oil did not vent out thru the "in" line. Hooked the lines back up and plugs and "burped" the engine. Oil level after that was at the max line.

Question.
Should oil have vented out or is it ok if it did not during the purge ?

 

[Tony_T]

Our experience :

Purged oil system as described in Rotax service bulletin. Disconnected "in" line and capped. The "in" line was left in place near the oil tank and we attached a longer hose to drain in excess oil out from that line. Pressurized the tank and removed plugs, handcranked and saw oil psi hit 55 in the green. Cranked the engine via the starter and pressure held steady at 60-62. However, no oil did not vent out thru the "in" line. Hooked the lines back up and plugs and "burped" the engine. Oil level after that was at the max line.

Question.
Should oil have vented out or is it ok if it did not during the purge ?

OK, If I understand how the Rotax works, it is crankcase pressure from piston blowby that purges the crankcase and returns the oil to the tank (and causes the burb which my wife gets a chuckle out of). Since when you are turning the prop with the plugs out there can be no crankcase pressure that is why with your return hose up at tank level no oil came out. And that is why the factory procedure has you route the return hose down below the crankcase during the purge so the oil in the crankcase drains. It is a pain to reroute the hose, I have seen a Rotax pro do the purge with the hose end up at tank level. So, I don't think this means your purge was not a good one, I assume the hammer handle test found no soft lifters.

Just my 02¢ worth, I have not read an official explanation of this.

Tony

 

[KALEWIS]

Tony,

We called vans and inquired about the location of the hose during the process and the answer was " no reason why it could not stay in place since oil is pumped upward anyway during normal operation". We have not checked the lifters yet.

 

[BigJohn]

I think Tony is right on with his explanation. When I first added oil to my new engine I followed the written procedures exactly, and all worked well. In subsequent oil/filter changes I do not purge the system, just drain the tank and change the filter. On start-up there is little or no delay in getting pressure back up.

But to get back to the original stated problem, no oil pressure indication, it seems to me there is something wrong with the pressure sensor or (more likely) the wiring to the Dynon. That is where I would start looking.

 

[Dave12]

To elaborate on what Big John stated, my D180 and related sensors has tried numerous times to lie about the Rotax. It has had me flying with CHT's in the red, EGT's in the red, low oil pressure, High fuel pressure, no oil pressure and oil temps in the red. Suspect the D180! The Rotax is an excellent product. My .02

 

[rvbuilder2002]

Tony,

We called vans and inquired about the location of the hose during the process and the answer was " no reason why it could not stay in place since oil is pumped upward anyway during normal operation". We have not checked the lifters yet.

Unfortunately, since not all of the tech. guys at Van's have a lot of Rotax experience, there was a mis- communication of info.

Tony has it right. Oil will not return from the crankcase unless the cyl. are producing compression when turning the prop. (it wont have compression if the bottom plugs are removed). That is why you are directed to lower the hose during the purge procedure so that it will drain via gravity. I usually do a purge procedure without lowering the hose, but I stop rotating the prop as soon as I see an oil pressure indication. This puts a minimal amount of oil in the crank case which is easily burped back to the tank after reinstalling the spark plugs

 

[KALEWIS]

Unfortunately, since not all of the tech. guys at Van's have a lot of Rotax experience, there was a mis- communication of info.

Tony has it right. Oil will not return from the crankcase unless the cyl. are producing compression when turning the prop. (it wont have compression if the bottom plugs are removed). That is why you are directed to lower the hose during the purge procedure so that it will drain via gravity. I usually do a purge procedure without lowering the hose, but I stop rotating the prop as soon as I see an oil pressure indication. This puts a minimal amount of oil in the crank case which is easily burped back to the tank after reinstalling the spark plugs

I assume that burping until it no longer gurgles will take the oil out of the crankcase. Spinning the prop by hand or starter shows an immediate rise in oil psi. Thanks for the info. Sounds like we are ok.

 

[Mich48041]

I assume that burping until it no longer gurgles will take the oil out of the crankcase.

I quit turning the prop when the oil gurgles. I assume that if the prop continues to turn, that the oil will continue to gurgle. Perhaps someone more knowledgeable will confirm or enlighten me.
Joe Gores