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[panhead1]

on an 06 103 after rebuilt having weird fluctuations with the oil pressure.  Any idea's on what can cause any loss of oil pressure on these bikes?  Before the top end when the oil was cold would run up around 45-50lbs then when warmed up always right around 32.  Now when cold might hit 35lbs.  Will run right at 32lbs while riding till you slow down and come to an idle.  Then it very slowly goes back up but will only hit about 28 and if you get down to 2000 rpms then it sitting around 20lbs. The motor does seem to make more noise when the oil pressure drops down.  But sounds like its a noise in the bottom end.  It still idles at around 10lbs before and after the rebuild.  I took out the cams and the oil pump today to see if i could see anything.  The oil pump has 20k miles on it and still looks brand new.  No marks anywhere and completely clean in the camchest.  Both the tenseners front and back look about new also. 

What made me think of the oil pump problems was i went and adjusted one of my exhaust lifters a little loose yesterday and it pumped right up at idle and made no noise.  Then as i took off riding you could hear that it was a little loose.  But would fluctuate.  Sometimes when giving it gas it would start making noise but when letting off the throttle it would pump back up but never really made noise at an idle.  So i thought maybe something in the oil pump wasn't working right.  The bike has made some weird noise since the top end was dont but its not really valve train noise.  Only other thing i did other than the motor was took the inner and out primary off to replace a tranny seal.  Not sure if i could of changed anything doing that. 

[panhead1]

No idea's or other things to check while i have things apart?  Kind of at a loss here.  Have checked about everything i can think of. 

[twinotter]

 Check the pressure relief plunger, make sure it is not sticking! A tiny spec of dirt would cause it to bind. If your oil pressure gauge is mechanical, check the line for leaks, cracks which would allow air into the line, causing a fluctuating gauge (ask me how I know-hehe). FWIW twinotter 

[sadunbar]

on an 06 103 after rebuilt having weird fluctuations with the oil pressure.  Any idea's on what can cause any loss of oil pressure on these bikes?  Before the top end when the oil was cold would run up around 45-50lbs then when warmed up always right around 32.  Now when cold might hit 35lbs.  Will run right at 32lbs while riding till you slow down and come to an idle.  Then it very slowly goes back up but will only hit about 28 and if you get down to 2000 rpms then it sitting around 20lbs. The motor does seem to make more noise when the oil pressure drops down.  But sounds like its a noise in the bottom end.  It still idles at around 10lbs before and after the rebuild.  I took out the cams and the oil pump today to see if i could see anything.  The oil pump has 20k miles on it and still looks brand new.  No marks anywhere and completely clean in the camchest.  Both the tenseners front and back look about new also. 

What made me think of the oil pump problems was i went and adjusted one of my exhaust lifters a little loose yesterday and it pumped right up at idle and made no noise.  Then as i took off riding you could hear that it was a little loose.  But would fluctuate.  Sometimes when giving it gas it would start making noise but when letting off the throttle it would pump back up but never really made noise at an idle.  So i thought maybe something in the oil pump wasn't working right.  The bike has made some weird noise since the top end was dont but its not really valve train noise.  Only other thing i did other than the motor was took the inner and out primary off to replace a tranny seal.  Not sure if i could of changed anything doing that. 

To be honest, what your oil pressure is doing now is more "normal". 

For a stock motor/oil pump, 45 lbs to 50 lbs. oil pressure when cold is abnormal...  What exactly was replaced/changed with your recent motor work?

[grc]

Yup.  Unless you are talking winter time, 35 psi at idle on a cold start is pretty much normal; significantly higher pressures tend to indicate a modified relief valve spring or extra heavy motor oil or perhaps a restriction somewhere.  Normal for a stock oil system tends to be 30 - 38 psi at normal operating temp and 2000 rpm, dropping off to around 8 - 12 psi at idle.  This stuff varies quite a bit because Harley's junky parts vary quite a bit.  If you've ever heard the old expression "close enough for government work", you might have an idea of how Harley approaches things.

Before you condemn the oil pump or other parts, make sure you're getting a true indication of oil pressure.  Sticking or out of calibration sending units can cause what you've described, so to be sure it is best to bypass the stock gauge and tap a calibrated mechanics gauge into the system.  And if in fact the oil pressure really is varying like you described and it's not a defective gauge system, I'd suspect the oil pressure relief valve in the cam plate.  There are tons of those floating around with lousy machining and tiny bits of crap that cause the valve to stick.


Jerry

[panhead1]

Sadunbar.  I just did a top end put in higher compression pistons and cleaned up the heads.  That was a bout it other than having to take the inner and outer primary off to fix a seal in the tranny.  


Jerry.  Even cold the bike wont idle at 35lbs when you first start it up. It used to.  Now when you start it up cold it will be around 20-25lbs.  Before the rebuild i would run right at 32lbs at around 3k rpm.  It still does now till you drop the rpms then it just never comes back up very well again.  Its kinda strange.  

I am going to pull the pin on the cam plate now and pull out the relief valve and clean it up and see if thats whats going on.  Just think the bike developed a gremlin and was pissed i redid everything on the bike because of a 2 dollar seal.  Cause i also put in the monotubes for the front end and ohlins shocks on the rear.  Only put on about 400 miles on the bike since i have done this trying to track down what the hell is making noise in the motor now.  I might go insane.

Oh by the way i am running the newer style oil pump and cam plate cause i did a conversion about 20k miles ago with that and woods t5-6 cams.  pulled off both tensioners and can't really even see any wear on them.  Was pretty surprised.

[panhead1]

Pulled out the relief valve.  It came right out and everything in there was clean.  Guess i will just put everything in the camchest back in.  Doesn't look like anything else could be wrong on this side.

[VANAMAL]

Im no expert but i think its designed to idle at a low psi. The cooling jets that squirt oil onto the piston bottoms have a relief valve that opens at ? Maybe 12psi. For some reason i cant recall they dont want those oilers opening at idle. What i read said 8-10 idle to 30-38 while running. Why it would change after whats been done im not sure. Jim says its more about volume than psi

[panhead1]

Im no expert but i think its designed to idle at a low psi. The cooling jets that squirt oil onto the piston bottoms have a relief valve that opens at ? Maybe 12psi. For some reason i cant recall they dont want those oilers opening at idle. What i read said 8-10 idle to 30-38 while running. Why it would change after whats been done im not sure. Jim says its more about volume than psi

your right.  I have no problem with it idling.  Thats always the same once its hot before or after the rebuild.  Really doesn't make much noise at an idle either. 

[cvobiker]

I'm thinking one of the 'O' rings in the oil pump is pinched....has me how I know that one.