Low oil pressure: Causes and remedies

['79Lowrider]

Generally speaking, what are the causes of low oil pressure in a Harley Davidson type engine?

Not specifically shovel related and for that my apologies.

Pulled the Ultima 120" out of the green 'King I wrote off a few years ago and had my independent install it in a '98 Roadking. I wanted to see some dyno numbers from it but between it being too cold to do a pull and issues with the dyno that wasn't possible. Picked the bike up a little while ago and noticed that the oil pressure light was flickering at idle. If you'd give it a blip of throttle it'd go out but come back on after a few seconds of idling.

Ordered an oil pressure gauge and installed it yesterday and upon initial startup (running Amsoil 20W-50) the gauge came up to somewhere between 20-30 psi. After running for a few minutes (the heads were starting to get warm to the touch) the oil pressure fell off to zero. Give it a blip of throttle and it would increase to 20 something psi but then gradually fall off to zero after returning to idling.

The motor has 2500 ish kms on it and the cylinders were pulled to remedy a seeping base gasket before it was installed. It never had any oil pressure issues in the old bike (pre-wreck) although I can't specifically say what psi it was making as I didn't have a gauge at that time. The engine died in the crash, it was not running when buddy got turned around and came back so it couldn't have run for more than a few moments after I let go of it. I don't recall anything from that escapade other than feeling the rear tire sliding as if on glass when I closed the throttle, attempting to correct it and then coming to in the ambulance some time later. lol Not my finest moment to say the least!

What should I look at first? Get into the cam chest and see that everything looks ok, or should I just pull the oil pump and get another? I talked to Beeker about it, (the shop owner that did the install) and he said even at a hot idle it should still have about 20 psi so somethings not right. He was away on holidays when the swap got done but his mechanics are all top pretty top notch and riders themselves so I don't think I can really blame it on them.

What kind of damage could have been sustained in the crash to cause this? Like I say, it couldn't have run for more than a few seconds after starting to slide and with all roller bearing bottom ends these type of motors should be able to run with next to no oil pressure for a few minutes at a time without doing any serious harm. Low oil pressure at a hot idle has always been a concern on Harleys but they seem to be able to handle it. This seems excessively low though...

Thanks!
Later,
Marc

[Dennman]

Ya don't wanna hear what I've got to say about this post.

['79Lowrider]

Go ahead and delete this this thread if it's too off topic but since the oiling system and bottom ends are basically the same between the two designs I thought I would ask for opinions.

[sunnydog]

Dammit Marc...don't say the E or T words around here, it's like swearing at the dinner table or farting in church lmao...maybe you could repost and say...my Shovel isn't developing oil pressure the way I'd expect? I dunno, maybe your oil pump has some blockages in oil passages due to all that dust from the land of shitty roads? It's certainly worth taking it off and exploring that possibility...simple things first eh? My Shovel shows 40+ pounds cold start, then settles in at about 12-15 pounds at operating temps. But it's just a lowly Shovel, not an ultimate machine lmao!

[coopsta]

When the bike was on its side it may have starved the pump from oil. Yes the bottom ends and the bushings don't mind doing with out oil for short periods of time but that pump could easily become scored without a constant supply of oil. Consequently that could be why at low idle your not seeing the pressure, yet with some revs it comes back up to 20psi. With an oil pump the tolerances are so close the slightest wear would probably not even be noticeable either, without some sophisticated measuring devices. Probably the best thing to do is get yourself a new S&S pump and install. What you may find out this summer when the weather gets much warmer you may be going down the highway and start hearing top end noise like unadjusted solid lifters, a rattle every so often. As your oil thins out your pump will not be able to supply enough pressure to keep your lifters pumped up properly.
I also highly recommend if and when you do change the pump to take your cone cover off and remove your pinion gear and oil pump drive gear while tightening up the pump body to the case to make absolute sure that there is not one tiny bit of drag on that pump drive shaft. The instructions will tell you you can get away without doing this step and just weasel the pump off and replace but you will never know if that shaft is binding. If it does bind and eventually shear the drive gear keyway you will potentially blow your motor due to no oil circulation.

OR………just put that shovel together ya fucker and leave that road king in the shed or better yet just put it on kijiji!!!!


Coop

['79Lowrider]

What can I say? I've always been an uncouth mf'er that gets a rise outta freakin' out the squares... lol

Thank you very much for the advice, gentlemen!

Now, back to your regularly scheduled programming... ;-)

Later,
Marc

[kootenai]

very important tip about having the cone cover off when tightening the pump body to the case,,,i didn't the first time,,discovered a topic about it on the u.s. site,,started getting the heebie jeebies,and whispering in my brain,,so I tore it open to check and sure nuff I had a tight spot,,,,saved me some grief going back in to it,,,,,,,,and like coop says just chuck it in the shed,,,save yourself some grief and just get that shovel runnin......................

[Clark Kent]

Hey Koots. You still getting that whispering in your brain??

[kootenai]

Hey Koots. You still getting that whispering in your brain??

shit man!!! I always have voices in my head,,its what gets me through life,,,me and my co pilots in this furry noggin of mine.........

[jmac11]

Koot,s do you get a little nervouce when the voice,s in your head go quite.I do couse I never know what the fuckers are planning next jmac

[Clark Kent]

You mofos think the voices in our noggins are related?

[Big Dave]

If the voices know each other were fucked

Dave

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