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Keep on Ridin’
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Discussion Starter #1
Before I get blasted for starting yet another oil pressure thread, let me say that I have been trying to research my problem for nearly a year, searching and reading every thread I could find that I thought might be relevant. I've PM'd a couple of gurus and talked to the local HD dealer service manager and a well-regarded local indie. If someone points out an obvious answer in a thread that I've missed, I'll gladly slink off into the bushes with my tail tucked. So here goes...

My 2004 Road King (bought used with 44K, don't know its history) has low to no oil pressure at idle when cold. The light will go out if I rev it above 1500-1800 rpm (estimated). Here's the curious part--Once the engine warms up completely (about 10 minutes) the light stops coming on at idle and stays out for the duration of the ride, even if I ride all day, 300 miles or more. Only if the engine completely cools back down (overnight) does the problem show up again. Even 'curiouser', when the engine is first started cold, the light goes out immediately for about 15-30 seconds before it comes back on to stay (at low rpm only) until full warmup is reached.

I just finished replaced both cam chain tensioners and disassembled the stock oil pump for inspection. I did not detect any damage. In fact, everything inside the cam chest looked beautifully clean, with the exception of the tensioner shoes. The outer had the expected wear and the inner was completely worn through--not really shocking. The o-rings that seal the cam carrier plate to the crankcase were pretty stiff and flat-sided (replaced all, of course) and I thought that would straighten things out. It did not. (sigh) I went to Harley straight 50 wt HD oil as an experiment--no help. Had also tried lighter weight 5w30 synthetic as a diagnostic attempt.
That made it worse. Got that out of there quickly.

If anybody is still with me so far, here's my theory: I think it has to be the pump itself. I think that it is not priming itself when cold and only picks up the oil from the feed passage after the gerotors expand from heat to close up tolerances. I think the oil that's still inside the pump from the last ride is the reason the light goes out immediately on startup, but when that oil is pumped out, the pump is losing prime.

Like I said, the pump looked fine inside to my inexperienced eye, so I was reluctant to spend money on a new pump. I have checked pressure with a test gauge and the gauge readings bear out what the light is telling me. Once the pressure comes up, I get 40-60 psi at 2000 rpm and 15-20 psi at idle. I have changed the filter and the oil pressure sensor with genuine HD parts. I've put several thousand miles on with this condition, with seemingly no ill effects. The engine runs great with no smoke, no oil consumption and no odd noises. But I have to get this fixed or I'll go nuts.

QUESTIONS:

While I just can't afford the SE high output pump upgrade or a Feuling pump, I'm wondering if anybody has tried one of the ebay oil pumps (high output billet oil pump). I have more time than money and I'm pretty fair with the wrenches.

Is there a way to tell if you're getting oil flow to the pump pickup hole from the pan?

Anyone? Anyone? I would really appreciate comments from Schmidty, Hillside or anyone. Dave63, are you lurking?
 

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May be the pressure relief valve in the cam plate? Maybe it's partially stuck. That would explain why the oil flows better when it gets hotter. Hotter equals thinner.


Sent from Motorcycle.com App
 

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Keep on Ridin’
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Discussion Starter #3
I thought about that. But wouldn't it have to be stuck open? Is that likely? I just don't know. I will be going back in soon and I think I will change the check valve and spring before I change the pump. Less work and need to do it anyway if I end up changing the pump. Just looking for input -- different takes or reinforcement.
 

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Keep on Ridin’
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Discussion Starter #5
Certainly willing to try that. But isn't that typically a fix for low oil pressure when hot? i.e. When the oil is thinner? (Trying to understand the 'why')

Thanks for the link.
 

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You are right, that is typically a fix for low pressure at cruising RPMs.

But what happens is tensioner shoe crud gets in that passage where the spring is, and leaves the bypass partially open causing low pressure at idle.

The Baisley spring will bump up the pressure to that of the newer 07+ oil pump.

Whether or not you change the spring, inspect the plunger that the spring pushes against to make sure it isn't sticking in the passage.
 

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Keep on Ridin’
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Discussion Starter #7
Will absolutely do that on my next trip in there. The hard o-rings sandbagged me--I just knew that was the problem - it wasn't.
 

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Keep on Ridin’
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Discussion Starter #9
Shim -- meaning the wavy spring washer inside the pump with the gerotors?
 

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Keep on Ridin’
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Discussion Starter #10
Ok. I see now. You're referring to the shim for the pressure relief valve spring. That would increase opening pressure, resulting in higher overall pressure. I have good oil pressure once the engine warms up. I think my next move needs to be pulling the spring and plunger and checking for burrs and trapped debris inside the cam plate bore for the pressure relief passage.

Thanks guys!
 

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Remove the spring and plunger. Clean all, including the passages. Replace. If you want to shim, a correct diameter flat washer works as well as the pricy one.
 

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Keep on Ridin’
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Discussion Starter #12
I think I just gotta bite the bullet and take the cam plate back out, take it all the way down for thorough cleaning. Also need to remove the oil pan for cleanout and blow out the feed and return passages through the trans housing. No getting around it. That's just labor time and gaskets. if that doesn't do it, then it's oil pump time.
 

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Keep on Ridin’
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Discussion Starter #13
OK, update time if anybody's still interested.

I opened up the cam chest tonight to install the Baisley spring and their relief valve plunger. I think I've discovered the cause of my problem. With the spring removed, I still can't get the plunger out. It's stuck in the bore of the cam plate. Which means it is not moving, which means it is more than likely stuck in an open or partially open position, allowing oil to continually by-pass, thus resulting in low oil pressure.

So my new question is: Does anybody have a hot tip for removing a stuck relief valve plunger without removing the cam plate? I'll do that if I have to, but that's adding another level of labor -- pushrods, lifters, cams, etc. I'm hoping to avoid that if possible.

My thought is to heat the cam plate casting in that area with a heat gun and hope it expands the aluminum more rapidly than the steel plunger. But I'm open to suggestions about how to grab the plunger and pull it out.
 

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Yup, use a magnet while tapping on the side of the cam plate with a plastic mallet. I've had to bang the plates on my wooden work bench already to get the plungers freed up and out ! Also, if the plate is removed, remove the plug from the top of the plate, spray brake clean into it and blow it clear with compressed air.
 

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Often the plunger gets a little cocked in the bore. Tap it gently with a drift, the correct size to fit the bore, being careful not to damage the bore. That usually will free it and then using a magnet, an easy out, or my preference, a tap the right size to thread into the plunger, extract it. Then clean the bore and usually replace the plunger.
 

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Keep on Ridin’
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Discussion Starter #18
Thanks, guys! All good suggestions. I was hoping to get it out without removing the plate. But even if I can, I'm not sure I'm feeling too good about not totally cleaning out all the passages and making sure the new plunger (Baisley) is very free in the bore. So I think I'm gonna pull it all the way back down. I just had it out to change my tensioners, so I have the SE adjustable pushrods -- won't be too big a deal to repeat.

Really appreciate the feedback. Just needed a little reinforcement on my thought process.
 

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Keep on Ridin’
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Discussion Starter #19
Fixed! The pressure relief plunger was really stuck. Would not budge with a magnet. I went to Home Depot to brainstorm the problem. Bought a 5/16" wedge lock anchor and it worked perfectly -- as well as if Harley had designed it as a special tool. I believe it was jammed on debris from the old destroyed inner cam tensioner shoe. Opened up the pump; it looked perfect, so I replaced the wavy washer and put it back together. I did a thorough cleanout of the cam plate passages. Now, the oil pressure light goes out immediately on startup and stays off at cold idle like it's supposed to.

:nod
 
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