March 28, 2024, 10:50:41 AM

News:


Oil pressure drops from 30 to 0

Started by 97dyna, July 08, 2017, 06:08:21 AM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

97dyna

The EVO motor seemed like it was running hot so I installed oil pressure gauge.  The oil pressure indicator light comes on prior to cranking and goes off at start up.  Oil pressure gauge shows 30.  Over a 15 minute ride the pressure slowly drops to 0.  But the oil pressure indicator light never comes on.  No oil leaks and the oil level is not decreasing. Prior to installing the oil pressure gauge, I removed the tappet screen and have removed and inspected after a few rides.  Both times the screen was clean.  I'm not hearing any any unusual engine noise.
So where should I start and proceed my troubleshooting?

Wicked

Guages are scary indicators at best. This "0" - is that at idle while hot? Idiot light still hooked up right? That switch is around a 3psi switch. What psi do you have while riding when hot?

rigidthumper

Another shining example of too much data, not enough information.

The system works on volume, not pressure. Pressure (as indicated on that gauge) is simply resistance to flow. If your oil light comes on before startup, that indicates the lamp and switch are working. The 30# cold indicates the pump is good, pushing thick fluid around the engine, with high resistance. As the fluid heats up, it flows more like water, so the gauge indicates this with a smaller number (less resistance to flow). At idle, there is very little RPM to spin the oil pump, compared to highway riding, where the pimp spins 3 times as fast. If the pressure drops to a true zero at highway speed, something's not right.  As long as the oil light doesn't come on while riding, then you have no issue.
Ignorance is bliss, and accuracy expensive. How much of either can you afford?

jbexeter

As others have said and hinted at....

1/ gauges only get trusted when tripled, two out of three being right, when verified and calibrated, and when installed correctly, this is before we even get into the arguments about mechanical gauges and remote sensing electronic ones.

2/ oil itself serves two purposes, it carries heat (and particulate waste) away, and it provides lube.

3/ in *plain* bearings provided there is enough *flow* to maintain the film, pressure isn't relevant, in fact in a reciprocating big end bearing (different story for mains) pressure can be nagative, eg centripetal force draws the oil out to the big ends, provided the supply is sufficient

4/ different parts of an engine require both different pressures and different flows when working, usually this is achieved by the layout and dimensions of oil galleries etc

5/ "oil pressure gauges" usually read at a set point just after the oil pump outlet, they don't tell you anything about flow or pressure to any other part of the engine, and I have *never* seen a street automotive application where the owner would not have been *better* served by ripping out the aftermarket oil pressure gauge and fitting a decent quality oil temperature gauge

6/ in a cold engine there is no heat for the oil to carry away, so it doesn't matter much if flow takes 60 second to get up to nominal, for EVERYTHING EXCEPT PLAIN BEARINGS

7/ for plain bearings flow is everything and it matters an awful lot if it takes time to build up, and it *will* UNLESS you have hand or electric pre oiling pumps you won't have these in automotive circles) so it's all down to oil temp and viscocity, so idle that bitch on zero load for at least 60 seconds, and keep loads and rpms *light* until oil comes up to temp.

8/ turbo motors (ok not HD related yet, maybe 2018 eh) the oil carries masses of heat away from the exhaust side turbine bearing, so *always* let the bitch idle for 2 or 3 minutes before shutting it down

9/ oil pressure gauge is useless in automotive circles, oil pressure switch and light not so much, if it was me i'd wire it with a press to make switch into the starter and ignition circuits so no minimum pressure no ignition, as others have said oil pressure switch is usually of the order of 2 to 5 psi, basically bugger all.

My advice is ignore it, pull the pressure gauge and fit a temp gauge, and if you're worried fit a new pressure switch, and like a new thermostat in a car, test it before you fit it...

HTH etc

Burnout

By the manual (which no one reads or choose to ignore) the recommended oil for summer temps 80° is 60w oil.

To run 20/50w oil in summer temps you should have an oil cooler on it. (it doesn't say that in the manual, read between the lines...).

Also Harley motors are not pressure lubed they only need flow, the only thing that needs any real pressure is your hydraulic lifters and that is only enough to keep them full.

If your lifters are not clattering and you are getting oil return, you are good to go.
If you can't see return oil in the tank, feel the oil filter if it's hot oil is being returned.

My advice is to take the gauge off and give it to someone you don't like (watch the light).

Also your idle should not fall below 950rpm, since the motor is basically splash lubricated.
Especially cold the motor needs 1500rpm to throw the cold thick heavy oil up to lube the pistons.
Letting the motor sit there and chug to "warm up" will ruin your pistons.
It is best to run the motor at 1500 rpm until the spark plugs are warm enough to ride away without stalling.
Then take it easy until the oil tank is hot.

"You can't see an oil pressure gauge at night"    :doh:
They don't call me Ironhead Rick just because I'm "hard headed"

thumper 823

The liquid filled O.P gauges have always worked for me .
It is in the traditional place on the engine.
True it is model "T"  technology, but it brings me some solace to look dwn at it once in awhile and see it .
You can put in higher spring rates in the relief valve, albeit I have been told it is both a good and a bad idea.
D Troop 3/5, - C/16 ,162AHC, Mekong delta.
Rising from the Ashes  UHIH

jbexeter

Quote from: thumper 823 on July 08, 2017, 01:18:18 PM
The liquid filled O.P gauges have always worked for me .
It is in the traditional place on the engine.
True it is model "T"  technology, but it brings me some solace to look dwn at it once in awhile and see it .
You can put in higher spring rates in the relief valve, albeit I have been told it is both a good and a bad idea.

Bad idea, the people who designed the engine (and specified the oil filter) know what the max safe pressure should be.

It's based on an assumption that oil being dumped by the relief valve isn't going to cool and lube the motor, and that must be a bad thing.. if it was a bad thing, manufacturers would all have saved 5 bucks and left the PRV out.

Flow is all that matters, and too much can be as bad as too little.

Oil temp gauge plus knowing your oil viscocity properties will tell you everything you need to know.

I've seen excessive oil pressure get in the seam between bearing shells and lift them, resulting in pickup and bottom end destruction, you NEED the wedge effect in the lube film

http://www.machinerylubrication.com/Read/779/journal-bearing-lubrication

thumper 823

I think you are referring to "skating" .
There are people who argue it both directions and I will not pose
or pretend I know more or even less.
What I do know is I have a slightly stronger spring.
I have ridden this to the ends of the earth .
Sturgis and more, and getting ready to do it again.
Two up and very HVY.
No problems.
BUT I do use an expensive oil, and an oil cooler.
It is no proof it works or not.
It works for me.
I like seeing the 10 lbs O.P. at idle .
D Troop 3/5, - C/16 ,162AHC, Mekong delta.
Rising from the Ashes  UHIH

Dan89flstc

Quote from: 97dyna on July 08, 2017, 06:08:21 AM
So where should I start and proceed my troubleshooting?

There is nothing to troubleshoot...
US Navy Veteran
A&P Mechanic

Burnout

Quote from: Dan89flstc on July 09, 2017, 05:37:47 AM
Quote from: 97dyna on July 08, 2017, 06:08:21 AM
So where should I start and proceed my troubleshooting?

There is nothing to troubleshoot...

Exactly!

The only trouble is a gauge is installed where there should be none.
Take the gauge for a long walk on a short pier.
They don't call me Ironhead Rick just because I'm "hard headed"

JW113

Old thread, yes I know, but now this exact same thing is happening to ME!!
:cry:

The basic info:

1992 Softail
Mostly stock
Just replaced the cases with Ultima for cracked at apex above tappet blocks
Oil pump stock
Oil: Castrol GTX 20w50
Temp: 60s-70s
Idle speed: 1000 rpm
I have both oil pressure idiot light and gauge (just added)

Symptom:
Before changing the cases, no issues what-so-ever (other than oil leaks).
Now, at start up, gauge pegs at 30psi, light off.
After 10-15 minutes of riding, the oil pressure drops considerably. Reads a tick over 0 psi doing 65 on the freeway, the oil light is not on, tappets not chattering.
At stop/idle, the light is on solid, oil gauge reads 0, but no noise from the tappets, although I've not let it idle for long lengths of time to see if  they bleed down. Might try that.
If I wind the piss out of the motor, the oil pressure goes up somewhere between 5 and 10 psi.
Oil is getting warm, and can be seen bubbling out of the return inside the tank.
Last weekend I pulled the tappet screen and pressure relief plugs, inspected, found nothing out of the ordinary.

OK, I read all of the above, and basically agree that if the tappets are not chattering, oil is getting pumped through the motor. That said, I've never had this problem of oil light on solid at idle and just off idle before. And now that there is a gauge on it, reading freakin' ZERO, that is not a comforting feeling.

So where is the leak inside the motor? Everything seems just fine until the oil (or the metal of the motor) gets the slightest bit warm.

-JW
2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber

MikeL

I know this is an evo post but my 1980 shovel will peg the oil pressure gauge with 60W oil when cold as it heats up it goes to between 5 and 10 psi at idle. At highway 35 to 40 psi hot.
97dyna say he felt it was running hot. Could it be sumping??? Maybe the breather gear isn't turning or sheared off the scavenge side woodruff key in the oil pump. I had a 1985 evo do that and it still returned oil to the tank just not enough it really messed with trouble shooting cause it was still pumping back to the tank.

                                                                                                       MIKE 

david lee

i flicked my shovel gauge yrs ago for not giving a correct reading

Flhfxd

Has any work been done on the oil pump recently? As in... pump gaskets replaced? Had a similar issue with mine and it turned out to be the the pretty rubberized gaskets were just a bit too thick. Replaced with paper ones and problem was solved.
"And the road goes on forever...... But I got one more silver dollar.....'

JW113

As a matter of fact...

When I assembled with the new cases, used James gaskets, which had silicone coated steel gaskets for the oil pump. Although I think I used that one on the pump-to-case gasket, which is the scavenge side, yes? At any rate, I'm going to replace the whole pump.

I rode home from work, air temp was maybe 80deg. 30psi at start up, then dropped to 20psi after 2 miles on the freeway, then 10 psi after 4 miles, and shortly after that, a tick over zero, just enough to keep the light off. If the rpms dropped below 1500-2000, light would flicker on, and on solid below 1500. I'm sorry, but you know what, this ain't right. Something is broken. I don't have the time to troubleshoot this to death, so will start with the shotgun approach and hope a new oil pump takes care of it.

-JW
2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber

MikeL

Quote from: JW113 on April 25, 2019, 07:38:17 PM
As a matter of fact...

When I assembled with the new cases, used James gaskets, which had silicone coated steel gaskets for the oil pump. Although I think I used that one on the pump-to-case gasket, which is the scavenge side, yes? At any rate, I'm going to replace the whole pump.

I rode home from work, air temp was maybe 80deg. 30psi at start up, then dropped to 20psi after 2 miles on the freeway, then 10 psi after 4 miles, and shortly after that, a tick over zero, just enough to keep the light off. If the rpms dropped below 1500-2000, light would flicker on, and on solid below 1500. I'm sorry, but you know what, this ain't right. Something is broken. I don't have the time to troubleshoot this to death, so will start with the shotgun approach and hope a new oil pump takes care of it.

-JW
This was many yrs ago for me. Not an EVO but..... I replaced an oil pump on a shovel with an S&S oil pump. I had to purchase a drill guide plate and drill an 1/8th hole at an angle using the plate to make the S&S pump work on that case. Don't know what would happen if this procedure was not executed.
Maybe the cases you purchased need a specific oil pump. Having an oil light flicker to me is like a ticking time bomb.

                                                                                                       MIKE

JW113

Well my friend, we are in complete agreement there! And this is not a flicker, is it a solid ON at idle and above. The oil pressure light means only one thing to me: NO OIL PRESSURE. How can that be good?

And I'm with you 100% on the new cases thing. The cases are Ultima. Guess what oil pump I ordered?

-JW
2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber

MikeL

Quote from: JW113 on April 26, 2019, 08:26:55 AM
Well my friend, we are in complete agreement there! And this is not a flicker, is it a solid ON at idle and above. The oil pressure light means only one thing to me: NO OIL PRESSURE. How can that be good?

And I'm with you 100% on the new cases thing. The cases are Ultima. Guess what oil pump I ordered?

-JW
JW Here another thing I do. I don't use multi vis lube oil in my bikes. Ages range from 1951-2007. I use 60sae full synthetic in all of them. A lot of people will say "oh the horror" especially when in a cold climate. Yes I live in Florida now, but I used 60sae when I lived in NJ just would let them warm up a bit B4 hitting the road when cold outside
I like seeing 10-12psi consistently at idle hot and 60sae does it for me.

                                                                                                       MIKE

JW113

I have no argument against 60wt oil, except in winter I find it makes the motor spin over slow. Especially with my 113", which won't hardly spin over with 10wt on a hot day! But I'm pretty sure that heavier oil is not the solution to this problem. A possible band aid, but I want to fix it. Before the case swap, it ran perfect with 20w50, and the only time the oil light was on was went the ign was on and the motor not running. So clearly I f'd something up swapping the cases.

-JW
2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber

Sycho01

What I would do is verify the oil press gauge is acurate at the bottom of the scale. Gauges are usually calibrated for accuracy in the middle of the scale. Ex: running press 30#'s the gauge would be a 60# gauge. The gauge may not be aaccurate at the bottom or top of the scale.
A cheap gauge most likely would not be acurate.
You could always swap out the gauge for 10# gauge if you have acess to one just to see if your gauge is ok.
I have seen many bad gauges.
I hope this info helps some.

fbn ent

To the OP...Ditch the gauge. As stated, your idiot light and lifters will tell you all you need to know.
'02 FLTRI - 103" / '84 FLH - 88"<br />Hinton, Alberta

JW113

OK, one more time...

I only put the gauge on because the idiot light is on solid at idle and perhaps up to 1500-1700 rpm. Would you really ride around town with the oil light on all the time? And at freeway speed (3000rpm), it's only registering about 2 or 3 psi after the motor warms up a little, as in after 4 miles? Sorry folks but that sounds like a problem to me.

-JW
2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber

fbn ent

"The oil pressure indicator light comes on prior to cranking and goes off at start up.  Oil pressure gauge shows 30.  Over a 15 minute ride the pressure slowly drops to 0.  But the oil pressure indicator light never comes on."

Does the pressure drop to zero on the gauge during the ride?
'02 FLTRI - 103" / '84 FLH - 88"<br />Hinton, Alberta

JW113

2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber

thumper 823

My EVO  idles at about  10 lbs no matter how hot it is .
No matter where it is .
Like many have said -
Swap out gauge,  see if that changes the results.
D Troop 3/5, - C/16 ,162AHC, Mekong delta.
Rising from the Ashes  UHIH