I am the original owner of a 99 Ultra with 16,000 miles. I thought I would share an experience I had recently witherratic oil pressure.I had no issues withthe HD petroleum lube oil I was using but decided to switch to synthetic,Syn3. After about 90 miles at 65 mphthe oil pressure gauge started to fall from ~30 psi to near 0 then back to various levels near 30. No unusual noises detected. I switched back to the HD lube oil I was using and again replaced theHD oil filter. Erratic gauge readings surfaced again after about 45 miles. In the process ofiinstalling a mechanical oil pressure gauge, I found that the oil pressure sensor / sending unit wason the verge of being loose. No leaks around the threads butalmostloose enough to unscrew by hand. I test rode the bike with the mechanical gauge for about 50 miles witha cruising pressure of~38 psi at 27/2800 RPM. The last mile to my house requires me to ride at near idle speeds which have historically indicated an oil pressure just above 0 on the instrument mounted gauge but the mechanical gauge was rock solid at ~18 psi.It appeared as thoughthe oil pressure sending unit was relying on the threads to complete the path to ground and the combination of being nearly loose with pipe dope may have been the root cause. I cleaned both the threads and the port plus applied a small amount of paste sealer before reinstalling the sending unit. So far oil pressure at the instrument gauge represents that noted on the mechaincal gauge after 100 miles at speed and idle.

 

Happens more than ya think - with all kinds of engines. Folks fergit that most electronics need an excellent ground, an' as a result fergit ta check fer such thangs.

 

Sending Unit!!

 

I have a 2002 elctra glide police special with a stage 3 screaming eagle kit already in it. About a month ago a lifter collapsed and had 4 new lifters installed and rode it a couple times since, but the oil gage was running about 45psi at 2000 and 30 at idle. went to go for a ride yesterday and fired her up all was well went about 1000' down the road stopped at the intersection and had no oil pressure and the light was on. checked with a mechanical gage and have nothing. what else can I check and what could be wrong with it? I hear of a lifter screen and it may be plugged but no one knows where it is. As I just had the oil changed and not sure what they put into it. Can anyone give me some info on what to check and where I can find it. Thanks Ray..