nstyn8

High pressure in frame oil tank?

13 posts in this topic

Hey everyone,

 

I'm wondering if anyone had any ideas as to what is going on here. I noticed that I had oil weeping out around my decompression lever. Initially I had assumed it was the seal going bad. However, I opened my top oil filler plug to check the oil and got sprayed by a geyser of oil. So now I think that system is being pressured up somehow.

It still seems to have good compression with no performance issues, but I'll confirm that with compression and leakdown tests this evening. There are no obstructions in any of the vent lines or the canister and air flows freely through all the hoses.

There is no oil/coolant cross contamination. Can that really be due to blowby when it still seems to have a ton of compression (at least judging by trying to kick start it). Is there a spot on the headgasket that could allow combustion gasses into the oil system without causing fluid contamination? Last drz headgasket failure I had it was noticeably burning coolant.

Is there something else that could cause pressure in the oil like that? I'm really confused.

It's a 2009 SM. Thanks for any ideas you might have!

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Yea I'm really confused too.  The oil tank is vented to the valve cover and the S/SM motor is vented to the intake boot. (E vented to atmosphere).  Something has to be plugged to build pressure.

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The oil tank is not supposed to be pressurized, .. BUT it does have an oil return line incoming to the tank near the oil fill, spitting oil as the return pump does its job and a vent line just below the oil fill,.
The air box does see positive pressure pulses, as the tank vent is directly connected tot he air box with no on way valve I can see some pressure pulses making it to the tank vent.

5b1fe2cb0a51e_oilspray.jpg.e130a90611133b9166724a68c063f9ed.jpg
Then we have 

Quote

sprayed by a geyser of oil.

I can see 10 people all looking at the same amount of oil mist calling it anything from "What oil mist?" To a "geyser "

Check to make sure the tank vent line is clear, not pinched or plugged. You could even disconnect the oil vent line from the frame , connect a 3ft piece of hoses as a test, start bike and see if you have pressure? then remove the oil cap and see if you still get a "geyser "

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5 hours ago, Erik Marquez said:

The oil tank is not supposed to be pressurized, .. BUT it does have an oil return line incoming to the tank near the oil fill, spitting oil as the return pump does its job and a vent line just below the oil fill,.
The air box does see positive pressure pulses, as the tank vent is directly connected tot he air box with no on way valve I can see some pressure pulses making it to the tank vent.

5b1fe2cb0a51e_oilspray.jpg.e130a90611133b9166724a68c063f9ed.jpg
Then we have 

I can see 10 people all looking at the same amount of oil mist calling it anything from "What oil mist?" To a "geyser "

Check to make sure the tank vent line is clear, not pinched or plugged. You could even disconnect the oil vent line from the frame , connect a 3ft piece of hoses as a test, start bike and see if you have pressure? then remove the oil cap and see if you still get a "geyser "

Thanks! I didn't even consider the oil return. I will definitely look into that.

 

As for the geyser, it was... significant. I rewuired a change of clothes and my driveway needed a pressure wash. It probably ejected half a cup of oil or maybe more, instantly.

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Over full perhaps? Was it topped off after sitting a while and not run first? Oil will seep through the oil pump when it sits and fill the cases. If the oil is checked it will appear low so the natural response is to add the pint or so to bring the level up to the line. Then it will pressurize and puke out once it runs a bit.

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8 hours ago, wdietz said:

Over full perhaps? Was it topped off after sitting a while and not run first? Oil will seep through the oil pump when it sits and fill the cases. If the oil is checked it will appear low so the natural response is to add the pint or so to bring the level up to the line. Then it will pressurize and puke out once it runs a bit.

Been there, done that, had to wash the t-shirt...

I have now learned to check via the level-screw on the case instead, after bike's been sitting for a while with no use.

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1 hour ago, adrian_vg said:

Been there, done that, had to wash the t-shirt...

I have now learned to check via the level-screw on the case instead, after bike's been sitting for a while with no use.

what method is that again?

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15 hours ago, wdietz said:

Over full perhaps? Was it topped off after sitting a while and not run first? Oil will seep through the oil pump when it sits and fill the cases. If the oil is checked it will appear low so the natural response is to add the pint or so to bring the level up to the line. Then it will pressurize and puke out once it runs a bit.

Unfortunately no. That was my first thought as well. I'm pretty good about draining both the case and the frame before filling back up but thought maybe I had possibly screwed it up. However j double checked and the oil level was correct. Thanks for the help though. I appreciate all the suggestions I'm getting here.

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