Anyway to test an oil pump?

[spyug]

I've sort of come to the conclusion that the oil pump in the 550 is kaput since I can't seem to register any oil pressure on the hydraulic gauge I made and my OP light will not go off.

Today I opened up the sump and could fine no evidence of any problem so I figure I need to find another pump. I did locate a used one fairly close to me ( and I do have one in the spare engine) but it got me to thinking how do I know they're functioning properly. I could be buying yet another problem and or the spare one could be junk too.

Is there anyway to test a pump outside the engine ?

Cheers all,
spyug

 

[gearhead13]

Oil pumps would have to be REALLY messed up to not put out at least some oil pressure. I would be more inclined to inspect the pump drive system. The gears that drive the pump off of the clutch basket. The circlip and the pin that hold the gear on the pump shaft maybe?

 

[Redman]

First of all, do you know how much oil pressure there should be? I understand it is real low and does not register on most avaialble oil pressure guages.

.

 

[tkent02]

No he has a high pressure system.

 

[tkent02]

Spyug, do you have a diagram of the oil system on that engine?

 

[Guest]

Manual page 153 that has an awesome picture of the whole oil flow system.

How did the engine sound ? I know they start making noise as soon as the pressure is gone.



Lets think of what could be causing it.

You should have 45-78psi being a plain bearing motor.

Nothing you can do outside the engine except pull the oil pressure test plug just under the ignitor cover and turn the engine over by hand to see if there is anything being forced out.

First of all, Oil pump might be not turning and it could be the gearing has disengaged from the clutch or the pin has sheared on the pump shaft or the pin driving the rotor.

2 oil pump loose from engine and bypassing or broken line somewhere that is allowing all pressure to escape.

3 pressure relief valve has failed.

4 pluged filter


The way I see it in the diagram is that oil is picked up from the sump, then is pushed into the filter cavity around the filter.
Then the oil passes through the filter and is diverted to everything.


I would take the clutch cover off and see if the oil pump turns, check the gears, turn the clutch , watch the center shaft on the pump rotate.

Then if that's good I would take the pump out and have a look at the rotor for really heavy scoring.

what did you make to test the oil pressure and where did you put it ?

 

[musicman]

Any noises? Like rod knock or anything that would come with no oil pressure? If you pulled the pan and it's clean as a whistle, then it has oil pressure I'd say, otherwise that sucker would be making one heck of a racket. I would confirm function of the oil pressure gauge, where you hooked it up, etc.

 

[spyug]

Thanks guys. I appreciate the feedback.

what did you make to test the oil pressure and where did you put it ?

I bought a 100psi hydraulic gauge with 1/8" feed tube and appropriate fittings. I fitted it to the OP sender hole on the top of the crankcase. I did test the gauge with a shot of airpressure to see that it worked. I cranked the engine with it fitted and got nothing. Needle didn't even move.

After I removed the gauge and cranked the engine with an open hole and the oil did"puke" out but not with any force at all.

My next step will be , as you suggest, to pull off the clutch and inspect the gear and pump shaft. With a bit of luck I'll get to that this weekend.

I'll let you know what I find.

Cheers guys,
Spyug

 

[Guest]

Ok so it does move oil.

How did it sound before all of this ?

If the engine is cold you have to wait for all the air to escape all of the oil passages and for all the oil passages to fill up and the filter cavity to fill up before you will get any pressure. So cranking it might not give you anything.

Also the sensor and your gauge is a dead end.

I would crank the engine over by hand with the sensor and gauge off until oil started pumping out without any air and then connect the sensor and gauge.

Its like having air trapped in your brake system. You can push alot of something but your really not accomplishing anything or pushing much pressure.

That's my theory now and I have a feeling its nothing mechanical.

 

[spyug]

When I said cranking, I was meaning the engine was running. The whole issue started when I was road testing the bike after rebuilding the brakes. The oil pressure light and side stand light didn't go off even after 4 or 5 minutes of riding around the neighbourhood ( and I did that on 2 occassions). On my 750 and 750 Kat the OP sensor lights go off in seconds after starting the bike so I expected this bike to do the same.

At first I figured I had an electrical issue but the more I checked the more I became aware that something is off with the actual pressure of the oil. As a plain bearing engine its supposed to put out over 35 but under 78 psi and there certainly hasn't been anything like that from my tests so far.

When running, the engine has sounded normal with no knocks or weird sounds so I wouldn't have suspected anything wrong had it not been for the lights.

In addition to checking the pump gear and shaft I'm thinking of removing the valve cover for a look see. I should check and adjust the valves anyway.

At the moment and until I can confirm oil pressure on the gauge I'm just not feeling confident that something serious is not going on. I just can't put my finger on it yet. while I really didn't want to tear in to this engine, I don't see as how I'll have peace of mind until I figure out what's happening.

Thank you for helping me think this through.

cheers,
Spyug

 

[tkent02]

While you're in the valve cover, check to see if the cam bearing surfaces are burnt yet.

 

[spyug]

While you're in the valve cover, check to see if the cam bearing surfaces are burnt yet.

That's what I had in mind. That would tell me if its been a long standing thing or has just happened.

I'll let you know.

Cheers,
spyug

 

[Redman]

.....
You should have 45-78psi being a plain bearing motor.
....

oh, okay.

.

 

[Guest]

Without oil pressure that thing would sound like a sewing machine up top and it wouldn't last long, I would think maybe 2 minutes.

I think your getting just enough and something is allowing bleedthrough.

what's the filter like ?

Where are you checking for pressure?

It should be the test plug just under the ignitor cover.

Did you put the o-ring back on when you put the sump cover back on ?

Is there an o-ring between the sump filter and case ?

Its either not able to suck or not its not pushing.

It could be a leaking stator cover gasket at the bottom where the oil channel is.

Could be a bad pressure regulator.

What have you done recently to the bike that has to do with the engine or oil cooler?

Need some more evidence to pin this one down.


I just read page 154 of the manual and its got me thinking the oil pan is where the problem is.

If the o-ring is missing then it would cause this,

If the gasket is bad it would also cause this because there are 3 possible places there that can leak.

If the oil cooler is working or not doesn't matter because there is a bypass in the oil pan that reroutes pressure to the filter directly and is pressure/temperature controled.

 

[gearhead13]

I had a thought.. If the main and rod bearings are worn out, they can bleed off a lot of oil pressure. Checking oil pressure is one way of telling the condition of bearings when looking to buy a vehicle.

 

[Nessism]

The oil pump design is almost foolproof so my guess is the problem relates to the wiring or maybe the sensor itself. What about performing some continuity checks on the switch, both with the engine running and without? It's possible the oil pressure regulator spring is stuck allowing oil to bypass but this seems remote unless there is a lot of crud in the crankcase. Dropping the oil pan would tell the story on this.

 

[JEEPRUSTY]

Could the filter screen being plugged cause this to happen?

The machine should definitley sound like a sewing machine with no oil getting to the top end via the top oilers.

Does the oil look clean at least?

 

[tkent02]

You guys are missing the point. Let's say there is a tiny bit of pressure, not much due to a blockage, broken spring in the pressure regulator, o ring blown out or whatever. Just because the cam hasn't destroyed it's bearing yet doesn't mean it's not going to, or that it's OK to run with such low pressure.

He said the oil comes out the oil pressure port when the engine runs, but not under much pressure. Sounds like a blockage before the pump or a leak after the pump to me.

Whatever it is he needs to find it.

I loaned my first MG to a new guy on the ship one night. He brought it back saying the oil light had a problem, it keeps coming on. It never occurred to him it might be a real pressure problem, it had a leak in the oil pipe alongside the head. That was the beginning of the end for that engine.

Edit, still don't have a diagram of this oil system, anyone care to post one?
Cliff, your link to the '83 GS550 service manual in the website won't work, been trying for three days.

 

[spyug]

Thanks for the continued interest guys. I'll recap as best I can.

The oil was changed with a new filter.
I did no other work to the engine.
There were no leaks anywhere on the engine.
The engine made no weird noises and ran and shifted smoothly. It was on this test ride of less than 5 minutes that I noticed the OP light and sidestand light stayed on.
I pulled the pan and have just removed the clutch cover and see no evidence of sludge or bits of metal.
The oil filter screen was clean with not buildup.
The o-rings ( 2 of them) were in place
We checked that the sensor will trigger with 3 or 4 pounds of airpressure and the lights will go off.
I was using the sensor hole on the top of the engine case (just under the carbs) to screw in my OP gauge. I did buy and try a new sensor and tested it to make sure it worked...made no difference.

It should be the test plug just under the ignitor cover.

I'm confused ignitor cover or pick-up coil cover? I didn't know, I'll have to look.

Oil pressure regulator, is that the device fixed to the oil pan, kind of a chrome tube? I'll need to check the fisches as the manual is unclear.

I've been working on trying to take the clutch basket out so I can pull the pump but am now hung up for want of a 31mm socket to remove the nut. I figure I've gone this far I might as well have a close look at it.

Its quite annoying to not be able to figure this out.

Thanks for staying with me guys.
Cheers,
Spyug

 

[tkent02]

The oil was changed with a new filter.
I did no other work to the engine.

Did it have normal oil pressure before you did this?
Did the oil pressure ever work correctly that you know of on this engine?


Spyug, Do you have a diagram of the oil system?