Oil Pressure Loss

[lhanscom]

On my way into work this morning I'm going down highway, and come upon an open stretch of road, and feel like turning it up, get up to about 140, and shut her back down again. No problems, and continue on my way doing close to legal speeds again. Probably about 25 miles later when I'm about to get off the highway, I look down and my oil light is flickering, then stays on as I'm slowing down. I'm not sure how long it was flickering because the bright sunlight makes the lights hard to see. As I'm putzing down the exit ramp to where I can stop, the bad noises start, and the engine stalls. I coast into a parking lot. I get off and check my oil level, it's right where it's supposed to be. After looking stuff over a bit, and not finding anything weird externally (no surprise), I start the engine again. Oil light is off. I'm now smoking a bit out the pipe, and out the breather on the head, but no bad noises. I go easy the 2 miles to work, and when I park, I'm no longer smoking, at least not that I could see. So on to my questions...

What are the possible causes of the pressure loss, that would go away after stopping the engine, maybe the pickup screen? I have 750 oil pump gears.

What is the likely damage? Initially I'm thinking the rings are baked, but with the smoke going away I'm not sure. I will do a compression check later to check things out. I'll change the oil later too, to check for metal, which I'm sure I'll find, just not too much I hope. I'm guessing worse case is the entire engine is messed up. Hopefully I can salvage it.

[gspaul]

Oil pump has to be the first look.could be you motor siezed slightly.
Ring's and bore, but I hope not!
Do the comp test and cross your finger's.
Good luck!

[Don Lobacz]

Luke, first of all, don't freak. Did you read the recent posts here of people who tried to blow up their bikes? It's amazing how tough these bikes are.

Here is my plausible explanation: your wide open romp pushed the oil pressure wastegate fully open and it stuck there for a while. This would mean that the pressure was lower than normal but there was still oil pressure and flow. The first place to look for damage in your motor would be the cam journals (Suzuki had a bad, perhaps unfair rap when the 16 valve motor was first introduced). I would just drive it and see what happens before digging into it further.

[gspaul]

Please do your comp check, and get your oil pressure checked first!

[lhanscom]

Please do your comp check, and get your oil pressure checked first!

Don't worry, I'll be doing that ASAP. Though I will be trying to get home if my oil light stays off.


About the waste gate, where is it located? If it's something that is going to stick, I would replace, or rebuild it if I can get to it without splitting the cases.

[gspaul]

I am afraid I don't know any thing about a "waste gate" in the oil system in your bike( Earl or Kieth please) only know of them in turbos!
In general there is a pressure by pass if your oil filter is blocked,but your oil pressure should then remain the same.
The filter screen is worth looking at in the bottom of the motor, it's very fine and once blocked,no pressure.
Sorry I have to go to bed now, it's thursday,12.45 am.
Let me know how you go, if your lucky your motor just gave you a warning, let's hope so!

[lhanscom]

Well evidently some real damage was done. Oil pressure never dropped again, everything sounded fine, until something broke, made some awful noises, and stopped the engine.

That's All Folks, I think I may be having a lot of GS1150 parts for sale shortly.

[Hoomgar]

Nooooooooooooooooooo!!!!!!!!!!!!!!!!!!!!


Dood, so sorry to hear it


Plans?

[mike J]

Luke, seems like I remember reading somwhere about oil pump shafts breaking sometimes with the higher volume gears. Just curious what kind of oil were you running? keep us informed about what you find. Mike J

[lhanscom]

I was running 20w-50 Semi Synthetic by GTX. I don't think the oil pump broke it's shaft, as I had good pressure after the pressure loss.

Don't know what my plans are yet.

[redliner1973]

please do an autopsy and let us know what happened..

[Jethro]

8O

Dude, that sucks big time.

Please let me know what happened!

Oh, and if the worst case scenario is true- dibs on your Dyna goodies!

[earlfor]

Awww Crap Luke, that really sucks! I dont know of any oil system wastegate in the 1150 other than the bypass at the oil filter for if the filter becomes clogged. Even at zero oil pressure, the crank bearings should be ok as long as there was oil in the sump. Oil starvation would kill the top end though.
The only thing I can think of as a possibility is that with the 750 pump gears installed, the oil pump may have been spinning fast enough at the high rpm you were at to cavitate the impeller which would result in no flow to the top end. That would also likely cause the oil pump shaft to be lube starved. I would not be surprised if the lockup is caused by your oil pump shaft being broken and the pump wedged in the housing against the shaft stub or something of that nature.

Just my guesses though. Let us know what you find when you get into it.

Earl

Well evidently some real damage was done. Oil pressure never dropped again, everything sounded fine, until something broke, made some awful noises, and stopped the engine.

That's All Folks, I think I may be having a lot of GS1150 parts for sale shortly.

[Hap Call]

Pull the clutch basket and look at the pump. I wonder if something happened to the drive gear on the pump, or the pump shaft itself.

If something did break later on it would probably be in the head. Roller bearings can go a long time without little or no lube getting to them, but the cams cannot.

Hap

[gspaul]

Very sorry to hear that mate! I hope you get lucky and it can be fixed.