82 GPZ 550 Loss of oil pressure after a drop

Guys, I need some help. I have dropped the bike on the right side. After that the oil warning light stayed on after starting up. I have found that issue on forums and burped the bike by loosening the oil filter. Everything seemed to be OK, the light goes off immediately after starting the engine. But, after a minute or so light comes back on. If I turn the bike off and start it again the warning goes off for another minute. Then it goes on again. What is happening? Should I burp it again or is my sender faulty? I Hope that this is not the case of real oil pressure drop. The bike have oil cooler installed.

How hard the drop?? the oil pressure switch should on the right side, below the timing rotor. If no oil leak is noticed, at least, I'd take the pickup sensor cover and have a look to begin with. Not just checking for oil leak, or looseness, but check the wires also, make sure they did not get nicked.

HIs 550 GPz should have an oil level sensor located at the oil pan, instead of an oil pressure switch behind the RH engine cover. I would check the wiring to it, but the sensor itself may be glitchy. Also, check the engine oil as per the owner's manual. easy.

Like Martin said, that bike uses an oil level sensor, so as long as you check the level in the window, it should be fine and the light is an electrical problem.

Here's a link to oil pan info showing where the sensor wold be located.
s3.amazonaws.com/gpzweb/OilPans/Kz550oilPans.html

Yours is type 4, but the type 5 photos show the sensor in place. Click on the photos to enlarge them and use the back button on your browser to return to the page.

loudhvx wrote: Like Martin said, that bike uses an oil level sensor, so as long as you check the level in the window, it should be fine and the light is an electrical problem.

Here's a link to oil pan info showing where the sensor wold be located.
s3.amazonaws.com/gpzweb/OilPans/Kz550oilPans.html

Yours is type 4, but the type 5 photos show the sensor in place. Click on the photos to enlarge them and use the back button on your browser to return to the page.

Thank You. Yes, there is a sensor on the bottom of the oil pan. The Oil pressure port on the right side of engine is plugged.
In service manual (supplement for 82+ models) it is stated that it is oil level gauge.
It is confusing that the oil gauge acts like that is not indicating oil level but pressure.
On ignition it is turned on and it goes off after engine start, after pressure is build.
Oil level is at max.

Not hard at all. Engine was off and I just tippet him of on the fence. No more than 50°. Still, He lost oil pressure.

Engine oil is straight on max. Oil is MOTUL 300Y 10W - 40. So, there is no Oil pressure sensor, but Oil level. After 1 minute the light goes on. If I kill the engine and start it
again within 2 sec, the light goes off immediately. For antoher 1 minute. Then it goes on again. WTH???

Where is the oil level in the window with the bike straight up on level ground, not running?

The oil level may be changing when the engine starts. Or maybe a wire is intermittently shorting when its running.

Either way, the level sensor does not measure pressure.

Because oil sloshing could make the oil level change quickly, the circuit probably has a dampener which delays the light going on or off. Turning the bike off resets the circuit. By restarting, you are just seeing the time delay.

You might able to test this by just leaning the bike away from the sensor with the engine not running. That is, if everything is working correctly. But if you have a wiring fault, it may always have a time delay then show the oil light. Maybe try it without starting the engine. Just turn on the ignition and wait.

As a side note, the 550's never have a pressure sender under the ignition cover. All sensors are in the pan whether they are level or pressure.

By Vabi1: .... So, there is no Oil pressure sensor, but Oil level. After 1 minute the light goes on. If I kill the engine and start it again within 2 sec, the light goes off immediately. For another 1 minute. Then it goes on again. ..

Most KZs have an oil pressure switch. Some models have an oil level switch, but for clarity's sake, I call it an oil level sensor to distinguish it from an oil pressure switch. It gets confusing. hee. The service manual has the description of how the fuel gauge warner unit should function & the procedure for testing it. These tests would cover the oil warning light. The owner's manual should describe the oil light as well.

Drop or Crash: Did you drop it or crash it? A crash is when you're riding the motorcycle & go down at any speed above a couple mph or something like that. If you crashed it, the oil level sensor mechanism may be sticking for some reason. maybe oil pan gunk has been disturbed & gotten inside the sensor. ??? If the wiring checks out, then I guess the next step is to remove the oil level sensor, then clean & test it as per the manual.

Odd. All I can say - odd. I played with my bike last weekend just to try to determine some pattern in that odd behavior.
Sometimes I turn the ignition and light doesn't come on even if the engine is shut.
I turn the ignition without starting the engine and the light doesn't goes on even after 15 min. - so much for timer.
If I leave it for 2 (or so) days, when I start the engine oil warning doesn't goes off until I stop the engine and start it again.
Then it goes off, and then, goes on after 1 minute. If I shut the engine and start it again immediately it stays off for another minute.
I'm still not sure is it a pressure or level sensor. Here is a picture (apologize for blurriness), maybe one of you will know for sure.
I'm thinking of striping everything at the engine's bottom apart, clean oil pan of sludge and replacing oil sensor. What else...?
There is a picture of the bike so we all know what we are talking about.
And, I didn't chrashed it, the engine was off and I just tippet him over on the fence. No more than 50° (long story)...

It's an oil level sensor. see breather-cover/oil-pan diagram for your motorcycle at Partzilla. Assuming it's actually available, it's an expensive part.

It might be possible to install an oil pressure switch. On the 550A & C models it's fitted to the oil filter flange in the oil pan, but the GPz probably doesn't have the threaded orifice. A machine shop should be able to do the job. I don't know where else you could install a pressure switch >> there might be a simple solution. :blush:

That is a picture of an oil level switch, (near the drain plug).