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High Oil Pressure and High Oil Temp

Tcheairs

Well Known Member
I've been having a problem with my oil pressure relief valve (Titan XIO 360 with 140 hrs TT). I had been running 45 psi in cruise flight and attempts to raise the oil pressure with the PRV (pressure relief valve) adjustments were not successful. Removed the PRV and cleaned the seat, spring and ball. Re assembled and still no increase in cruise pressure, however cold starts (85 degrees ambient temperature) produced 55 psi at idle and 75 at engine runup to 1700 and 100 degrees oil temp. So, I suspected a weak spring in the PRV which weakened with oil temperature rise to 185*. (All of my EMS temp and pressure values have been verified with mechanical gauges.) and I tightened it to within 2 or 3 threads of full travel. Flew to my destination still looking at 45psi oil pressure.

But today on my return trip, after takeoff and during climb to altitude, the oil pressure pegged at 99 psi on my Dynon D-100 and oil temperature rose to 210* resulting in a nervous turn back to the airport. Oil pressure came back down to about 80 psi at idle. I have never seen these high values before and that pretty well shoots down my weak spring theory and obviously the PRV kicked in with overkill.

So, I guess I need to bite the bullet and order a new Oil pressure relief valve since mine seems to have gone "nuts". Other ideas? Comments? Thanks
 
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Mechanical gauge hooked up directly to oil pressure outlet on top rear of engine just behind # 3 cylinder. This is a continuation of a series of my posts on this problem. I'll send you a link so that we don't have to start at square 1 with the questions. Verified actual mechanical pressure. Also verified accuracy of VOD transducer with air pressure..This problem goes far beyond all of the actual indication questions. The indications on the EMS have been verified as accurate.

https://vansairforce.net/community/showthread.php?t=198929
 
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Any chance you have a restriction in the breather line? A friend had similar symptoms and didn’t find it until the front seal failed.
 
I haven't checked the breather line. going to pull the sump screen however and see if there is anything in it..
 
Let me confirm. You were getting 15 at idle and 50 at cruise for a long time. You took apart and reassembled the relief valve and the next flight, you got 75 at idle and 45 in cruise? Followed by a whole bunch of inconsistent OP readings?

If the only change was this, I would have someone with experience look at the relief valve, as this is the likely culprit. I would consider a sticking OP sender, however, it was very consistent UNTIL you took apart the relief valve. That really points to something going on in the valve.

Was the mechanical gauge installed during the above flights or did you put the old sender back for the flights?

Was there a round cage sticking out of the case that holds the ball centered over the hole? Did the inside of the relief assembly have a bore that was just large enough to hold the ball or was it larger, where the ball could move around? Also post a pic of the relief assembly (on the engine is fine). When I had the mismatched relief assembly on my 540, I would get high readings at idle and lower readings at full power and it was somewhat intermittent, with occasionally higher readings at full power.

I am thinking the ball was pushed off the the side and held there, giving low readings across the board. After reassembly, the ball was now on the seat and you got the high idle pressures. As soon as the RPMs come up, the ball goes off to the side and pressures drop. However, this time it is doing what mine did and pop back onto the seat when the RPMs drop. The reason it is doing this NOW, is that you have made the spring tighter, so it can't get permanently pushed off to the side. The tear apart allowed the ball off the edge, where before, tightening the spring just further locked it to the side.

Larry
 
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No cage on PRV...ordered a new one from Superior this am. Also ordered the LL11713 heavy duty spring just in case. Going to pull the oil sump screen just to make sure there's not something else going on. Thanks.
 
No cage on PRV...ordered a new one from Superior this am. Also ordered the LL11713 heavy duty spring just in case. Going to pull the oil sump screen just to make sure there's not something else going on. Thanks.

Re-read post, as i added. Also, if you are getting 75 psi at idle, your problem is NOT a weak spring. The fact that you saw 100 PSI at high RPM would indicate no issues with the sump. Please answer the questions I asked.
 
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Re-read post, as i added. Also, if you are getting 75 psi at idle, your problem is NOT a weak spring. The fact that you saw 100 PSI at high RPM would indicate no issues with the sump. Please answer the questions I asked.

Your relief system MUST have some way of holding the ball centered over the tapered seat, otherwise you get high psi at idle and low psi at high RPM. It is either a cage attached to the crankcase OR a relief assembly with a bore small enough to hold the ball centered. They make two different relief assemblies. One with a small bore to hold the ball and one with a large bore to fit over the cage on the case. I am guessing you have the latter, with no cage on the case. This would explain your most recent OP readings.
 
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I think your question I missed concerned the mechanical gauge. It was connected while on the ground. The engine was ground run to 2000 rpm and the mechanical gauge agreed exactly with the Dynon D-100 EMS in the cockpit. I also verified the reading of the electrical transducer by applying 60 lb of air pressure and it agreed exactly with the reading on the EMS. My PRV does NOT
have a cage.

I'm unable to send you a photo of it because I don't know how to post photos on this forum. Requires a web address for the photo and my photos don't have a HTTP address. If you want to PM me an email address, I'll send you a photo of the valve.

thanks for your input.
 
I think your question I missed concerned the mechanical gauge. It was connected while on the ground. The engine was ground run to 2000 rpm and the mechanical gauge agreed exactly with the Dynon D-100 EMS in the cockpit. I also verified the reading of the electrical transducer by applying 60 lb of air pressure and it agreed exactly with the reading on the EMS. My PRV does NOT
have a cage.

I'm unable to send you a photo of it because I don't know how to post photos on this forum. Requires a web address for the photo and my photos don't have a HTTP address. If you want to PM me an email address, I'll send you a photo of the valve.

thanks for your input.

Do you remember if the inside bore of the relief assembly was the same size as the ball or larger (about 1.5 X ball size)? I assume there was no cage sticking out around the tappered seat on the crankcase.
 
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I do not know the answer to the ball fit in the cylinder...I had an A/P remove, clean and replace it..I'll know more when my new PRV arrives later this week. As I said in my post, I tightened the stud to within 2 or 3 threads of full travel. Then the high oil pressure (and abnormally high oil temp) occurred. I'm going to back off the stud 2 whole turns and run on the ground to see what I get. However, I will install the new PRV when it comes in. I also ordered a heavy duty spring just in case it is needed. I also will pull the oil sump screen and check before I install the new PRV.

FYI I called the Continental tech rep in Fairhope and he told me that there were some problems with the PRV on engines assembled in San Antonio in 2012, the year my engine was assembled. I am not the builder. I bought the airplane from the builder with only 125 hours TTAFE..
 
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Cut the filter. Remove the sump screen and check the ID.
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The sump screen is made from perforated metal rolled into a tube. The oil from the sump is fed to the inside of the tube. It then flows from inside to outside, and onward up to the pump. Any captured trash will be found on the inner surface. Perhaps "ID" was a poor term.

The oil filter is in the flow path after the pump. Cut the filter can open for a visual inspection of the element. A blocked element causes the filter's internal bypass to open, or in the case an an AC-style filter adapter, opens the adapter's own bypass. There would be a pressure drop associated with bypass opening.

These are not "Do this to fix your problem" items. They are task items to methodically check off the list given any case of low oil pressure. Either could be the cause, and/or inspection determines if the low pressure has done damage.
 
Roger Wilco Dan..I know these inspections are important. I will accomplish both before installing and operating with the new PRV which will be in Thursday. I also ordered a spare high tension spring.
 
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