rocketman Posted October 18, 2017 Report Share Posted October 18, 2017 I have a factory rebuild engine in my bravo with a new JPI instrument. Oil pressure in cruise is typically 55 psi at 2400 rpm 65% power. Sometimes it gets down to 52 psi. That reading puts the gauge in the yellow. I have checked the JPI with a calibrated gauge and the JPI is only 2 psi less than the other gauge. So the JPI is accurate enough. The pressure transducer is located above the right mag and not over the right alternator. Oil temp is stable and fine. Oil level typically 9 quarts. No oil burn. All other engine parameters are normal. any suggestions? Is this oil pressure normal? What are other bravo pilots experiencing. The engine is under factory warranty. Ron Dubin Quote Link to comment Share on other sites More sharing options...
KSMooniac Posted October 18, 2017 Report Share Posted October 18, 2017 I have a factory rebuild engine in my bravo with a new JPI instrument. Oil pressure in cruise is typically 55 psi at 2400 rpm 65% power. Sometimes it gets down to 52 psi. That reading puts the gauge in the yellow. I have checked the JPI with a calibrated gauge and the JPI is only 2 psi less than the other gauge. So the JPI is accurate enough. The pressure transducer is located above the right mag and not over the right alternator. Oil temp is stable and fine. Oil level typically 9 quarts. No oil burn. All other engine parameters are normal. any suggestions? Is this oil pressure normal? What are other bravo pilots experiencing. The engine is under factory warranty. Ron Dubin If it is like the 360, is simply adjust the oil pressure up...simple task that your local mechanic should be able to do. Some use extra washers against the relief spring, others have a screw adjustment. Sent from my LG-US996 using Tapatalk Quote Link to comment Share on other sites More sharing options...
carusoam Posted October 23, 2017 Report Share Posted October 23, 2017 Any notable change in oil temp? I don't have a guideline for a temp vs. viscosity curve, especially with multi-weight viscosity engine oils... a little warmer is less viscous and will drop the pressure... Akin to warmer oil at the top of the green oil T range, starts showing lower oil pressure near the bottom of the oil pressure green range... Have you changed to a new engine oil since break-in? If the engine break-in was done on one oil and the long term oil is lower viscosity... it may make sense to have the oil pressure valve adjusted to meet the engine's spec with the long term oil in it. Check and see what oil got put in it. In case you didn't get the weight you were expecting... PP thoughts only, not a mechanic... Best regards, -a- Quote Link to comment Share on other sites More sharing options...
Bravoman Posted October 23, 2017 Report Share Posted October 23, 2017 (edited) Ron as you may recall we both got factory remains installed about the same time. My oil pressure reads between 60-65 psi which is in the green. I have about 230 hrs on my engine. Runs great. I may however have an engine driven fuel pump issue. At low altitudes and on the ground no problem so far as the fuel pressure gauge reading is concerned. Reads 35 -40. On an extended climb to high teens the needle bounces quickly between about 20 -30 psi. In cruise this smooths out to 35 or so psi. When I hit the electric pump it reads a solid 40 psi. The engine never skips a beat but like you I don’t like anything approaching the yellow. We have notified lycoming about this issue. Never a dull moment. Edited October 23, 2017 by Bravoman Quote Link to comment Share on other sites More sharing options...
INA201 Posted April 29, 2018 Report Share Posted April 29, 2018 Just got my plane back from annual and had the oil cooler rebuilt. I noticed my oil pressure in flight 24” 24mp was close to 60 in the green and temps around 178-180(oil cooler doing great). I thought the pressure was a little low as it’s usually 70ish. Checked the oil level and it was at let’s say 4.8-5qts somewhere in there. Would that cause oil pressure to be lower? Has anyone experienced lower pressure with reduced oil volume? I’m thinking the rebuilt cooler, new filter, 7 hours or so since oil change lowered my oil level to this level too. I checked it when I got the plane back and was at 6.25 qts but hadn’t been run. The plane burns oil at 7-10 hours per qt depending. Quote Link to comment Share on other sites More sharing options...
carusoam Posted April 30, 2018 Report Share Posted April 30, 2018 Two things that change OilP... Temperature and oil type... Then there are the other things like the oil pressure regulator/spring and bearing wear..... Anything like that going on? Best regards, -a- Quote Link to comment Share on other sites More sharing options...
Awful_Charlie Posted April 30, 2018 Report Share Posted April 30, 2018 I don't have the JPI oil pressure option (although it is something I keep thinking about adding), but my understanding is that the oil pressure is *always* measured from a point off the accessory housing - the option at the front of the engine is only for oil temperature. That said, I normally expect ~70PSI on the ship gauge after everything is up to temperature, but that is on the 2200 hour engine that is just coming out to be replaced with a factory rebuilt :-o I'd need the opinion of someone who knows then engine guts better than me, but my understanding of the oil relief valve spring/washers is that it sets the maximum pressure, and normally only comes into play with cold oil - ie if you see a higher figure after the first start up of the day, then adjusting this won't do a lot @M20Doc can you shed any more light? Quote Link to comment Share on other sites More sharing options...
tls pilot Posted May 3, 2018 Report Share Posted May 3, 2018 Ron Please refer to one of my first posts in Oct 2014. The issue remained into early 2015 for my engine. see post.... Bravo Oil Pressure By tls pilot, October 9, 2014 in Mooney Bravo Owners after reading old post, a few thoughts.... I do not recall when you purchased your reman from Lycoming. But it seems like it was around 2015 when they were finally figuring out my issue. Is your issue decreasing oil pressure as you climb? and Then as you decrease altitude the oil pressure increases? In my case the issue was easily documented since I have dual oil pressure guages, the ships transducer guage and a direct reading Scott. As well, I have two oil temp guages, the ships and a JPI. Once the engine was installed, the oil pressure difference was related to altitude. See the original post, basically, the higher I went the lower the oil pressure. It was a consistent decrease in oil pressure on climb until I reached FL 140 where the oil pressure went into the yellow. At that point, I did not go higher. I documented the incremental oil pressure loss with a spreadsheet and pics. Noting the readings on both pressure guages and the oil temps. Lycoming suggested adjusting the oil relief valve, an easy task on our engine, no need for washers, ( you can also het a stiffer spring, purple or white?) use a 9/16 th wrench on the aft cylinder in front of the oil cooler. The problem is this is NOT the fix. It only allowed me to climb to FL 170 vs FL 140 before the oil pressure went into the yellow. No real fix... At least in my case it was not a fix. If your oil pressure is decreasing with each 1000 feet as you climb, it may be the same issue I had. Lycoming is and was clearly aware that the new lifters (tappets), parabolic ones, used in our TIO540AF1B was not allowing proper oil pressure especially once we got into the FLs. Apparently due to our oilers and the ability of the oil pump? It is a practice that was stopped sometime in 2015 or early 2016, with Lycoming only using straight tappets. In my case, after flying the reman engine for 21 hrs, the engine was pulled and rebuilt w another new camshaft and new tappets, the original design type. After that, I can fly up to FL240 without any oil pressure drop. It certainly fixed the issue. No sense having an engine and plane that can fly at FL240 but you need to fly with the oil pressure in the red or yellow.... IF you have the same data of oil pressure loss w altitude increase, I suggest you call Lycoming and ask very specific questions as to what tappets were used in your install. Obviously, there are other issues that may cause a drop in oil pressure; Boyles law and oil temps, the turbo system, and prop governor. Good luck. 2 Quote Link to comment Share on other sites More sharing options...
carusoam Posted May 3, 2018 Report Share Posted May 3, 2018 TLS P, Nice Pirep! I’ll invite @Bravoman and @rocketman to stop by and read that piece... Its been a while since this post was started... Best regards,, -a- Quote Link to comment Share on other sites More sharing options...
mike_elliott Posted May 3, 2018 Report Share Posted May 3, 2018 9 hours ago, tls pilot said: In my case, after flying the reman engine for 21 hrs, the engine was pulled and rebuilt w another new camshaft and new tappets, the original design type. After that, I can fly up to FL240 without any oil pressure drop. It certainly fixed the issue. @tls pilotDid Lycoming cover this change, assuming it was a Lycoming re manufactured engine? If they did, were they the ones who installed the new camshaft and tappets? Are the new tappets the new Lycoming DHC tappets? Quote Link to comment Share on other sites More sharing options...
rocketman Posted May 3, 2018 Author Report Share Posted May 3, 2018 I just called lycoming and talked to tech support. They said they not aware of any tapper issue with these engines. I’m not inclined to believe them. My engine was made in 2015 so it would fit into the time frame. I never paid much attention to altitude but I know what I’m going to do next week when I fly it next. Yep get my o2 masks on and check it. 1 Quote Link to comment Share on other sites More sharing options...
Bravoman Posted May 6, 2018 Report Share Posted May 6, 2018 I have not noticed any problem with oil pressure even into the flight levels but I’m gonna double check also. I’m also going to check my engine log but I believe my engine was made in mid 2016. Quote Link to comment Share on other sites More sharing options...
Piloto Posted May 6, 2018 Report Share Posted May 6, 2018 Oil pressure is mostly affected by bearings and rings wear. Check the oil pressure at idle, if it goes down slightly then most likely is due to the pressure relief valve setting. José Quote Link to comment Share on other sites More sharing options...
rocketman Posted May 6, 2018 Author Report Share Posted May 6, 2018 My oil pressure does drop with lower RPM. Quote Link to comment Share on other sites More sharing options...
rocketman Posted May 9, 2018 Author Report Share Posted May 9, 2018 I took my Bravo for a 30 minute flight at 3000 ft MSL and the oil pressure was still around 50. So I guess its not the tappets and need to turn the pressure valve up a bit. Just don't understand why the factory sent it to me with low oil pressure in the low greens. Quote Link to comment Share on other sites More sharing options...
Awful_Charlie Posted May 9, 2018 Report Share Posted May 9, 2018 4 hours ago, rocketman said: I took my Bravo for a 30 minute flight at 3000 ft MSL and the oil pressure was still around 50. So I guess its not the tappets and need to turn the pressure valve up a bit. Just don't understand why the factory sent it to me with low oil pressure in the low greens. What figures did Lycoming get on their test cell? (printed on the yellow "Engine Test Log" sheets) AIUI the low value is 75PSI, so if yours is significantly less, then on the basis you have checked the gauges/senders, maybe you have an installation problem? Quote Link to comment Share on other sites More sharing options...
JohnB Posted June 18, 2018 Report Share Posted June 18, 2018 I’m having the same issue drop in oil pressure with increasing altitude, for me it’s about 1psi drop with every 1000 feet above 11k starting at 55psi. My engine was built in 1993. Already did all of the attempted fixes above except changing tappets. I’ll be calling Lycoming tomorrow. But is this an actual problem? I heard from reliable mechanic that it’s not unusual for bravos to run fine below 55psi at altitude. Quote Link to comment Share on other sites More sharing options...
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