• Required reading for all forum users!!!

    Welcome!
    Register to access the full functionality of the GSResources forum. Until you register and activate your account you will not have full forum access, nor will you be able to post or reply to messages.

    A note to new registrants...
    All new forum registrations must be activated via email before you have full access to the forum.

    A Special Note about Email accounts!
    DO NOT SIGN UP USING hotmail, outlook, gmx, sbcglobal, att, bellsouth or email.com. They delete our forum signup emails.

    A note to old forum members...
    I receive numerous requests from people who can no longer log in because their accounts were deleted. As mentioned in the forum FAQ, user accounts are deleted if you haven't logged in for the past 6 months. If you can't log in, then create a new forum account. If you don't get an error message, then check your email account for an activation message. If you get a message stating that the email address is already in use, then your account still exists so follow the instructions in the forum FAQ for resetting your password.

    Have you forgotten your password or have a new email address? Then read the forum FAQ for details on how to reset it.

    Any email requests for "can't log in anymore" problems or "lost my password" problems will be deleted. Read the forum FAQ and follow the instructions there - that's what we have one for...

  • Returning Visitors

    If you are a returning visitor who never received your confirmation email, then odds are your email provider is blockinig emails from our server. The only thing that can be done to get around this is you will have to try creating another forum account using an email address from another domain.

    If you are a returning visitor to the forum and can't log in using your old forum name and password but used to be able to then chances are your account is deleted. Purges of the databases are done regularly. You will have to create a new forum account and you should be all set.

Oil Pressure Drop

  • Thread starter Thread starter ryonker
  • Start date Start date
R

ryonker

Guest
I just recently installed an oil pressure gauge and an oil cooler on my 79 GS 750. Hook up went just fine.

Started it up last night and everything worked fine (had about 7 psi at start up and then around 3 at idle).

I just took it for a drive and I got about 6 to 8 psi when accelerating and then 3 at idle. Then I noticed my oil light flickering at idle and at gear changes. Then at idle my oil pressure dropped down to about .5 psi, but would go up when I accelerated.

Any idea what might be causing this? I do have a small leak where one of the nipples screws into the adapter. I am not sure how much leaked but with the bike on the stand there is plenty of oil, but I could be little low considering the cooler and lines store some oil too.

Thanks for any help.

Rick
 
Hi Mr. ryonker,

Where is your idle set? If the idle too low it might trigger the pressure sensor.


Thank you for your indulgence,

BassCliff
 
It's at about 1000 rpms. But I will turn it up a little and see if that helps.

Thanks!
 
But thinking about it, the pressure sensor light lights up when my pressure gauge also shows low pressure (.5 to 1 psi). So that is working as it should, right?
 
I just added a little oil and started it up. It actually idles just fine around 1300 rpms. But at 1300 rpms the pressure is really low (about 1 psi) and the light comes on.

But (with the bike sitting in neutral) I rev the engine to 2000 rpms and the psi goes up to about 3, and the light goes off.

The funny thing is that this didn't happen until I took it for a test drive. I let it run for a while last night with no problem, and at initial start up today the psi was very acceptable.
 
As an addendum...prior to installing the cooler, my oil light has never come on.

I am sure there is a reason. But I am not running it with questionable oil pressure...so I may be getting rid of my adaptor and cooler unless I can fugure this out.
 
how much oil did you add? those coolers will hold a quart or so.. your oil level will seem fine when you measure it, but when you start the bike and get the oil really circulating, a quart is gonna be in the cooler, creating lower pressure everywhere else.
 
Oil Cooler

Oil Cooler

The oil cooler (depending on how you routed it) will reduce oil pressure some. Apparently it did just enough to trigger your pressure switch.

What did you use as a pressure switch plate/block?

Posplayr
 
Not even close to a quart. Maybe that's my problem. I just wasn't sure how to determine the amount.

Any thoughts? Nessism suggested running the engine then pinching the hoses. I am not sure how hard I want to pinch them though.

Should I just keep adding and see if it raises the oil pressure?
 
Just a thought, if you placed the cooler below the height of the crankcase I am assuming its connected with rubber hose. And checked the oil level while on the center stand, the oil should flow into the cooler and you would be able
to see how it affects the crankcase level. Then add oil to the normal level this would let you know how much oil the cooler and hoses take. When you lift the cooler on to its mounts the crankcase would show high till you ran the motor. Just thinking.
 
If your block-off plate is like the one that I just helped install on TheCafeKid's 1100, there is a place to put your pressure sensor assembly. However, it appears to me that the whole concept of the pressure sensor is that pressure will cause it to move away from the electrical contacts that turn on the light. If the bore into which the sensor mounts is a bit larger in diameter, oil will flow around it more easily, instead of pushing it away from the contacts. This could be why your light is coming on. Although the block-off plate is a quality piece of work, the specs might be just a bit different from stock.

.
 
My oil pressure gauge comes off the side of the crankcase---it's one of those from Bruce.

Yes, Steve, my oil plate adaptor is exacly like the one you installed for Cafekid.

Why would the pressure start off ok and then become a problem (if it's not the oil cooler using up more of the oil?)

Steve, what should I check then?

Thanks!
 
The oil pressure light will come on unless you are capturing 100% of the oil flow coming up through the oil port and sending it up past the oil pressure sensor. If there is any bleed off, often as a result of how the extension piece fits down into the oil port on the engine, the oil pressure light will come on. I’m not familiar with Terry’s adapter but I assume there is a piece that fits down in the oil port of the engine. Check to see if the top of the piece is flush with the top of the oil cavity – if the piece is sitting down in the cavity, there will be bleed off when the top plate is installed.

Another reason the oil light sometimes comes on is because the oil pressure sensor is compressing the plunger spring too hard on the sensor itself. You should be able to watch the plunger turn as you are screwing in the sensor – the sensor will stop turning when it hits the stop on the bottom. The amount of compression on the plunger should only be very slight – about 1 turn of the sensor. If you are getting too much compression you need to fit a thicker o-ring on the sensor to stack it up higher. This will allow the plunger to be pushed out of the way easier thus interrupting the ground path that turns the light on.

Edit: regarding why the oil light starts off okay and then comes on later, it's because the oil is thinning out thus the pressure is lower.

Hope this helps.
 
Last edited:
I honestly can't tell what other variables there are to adjust other than perhaps I did not add enough oil.

Both the sensor light and the oil pressure gauge agree. So is it still possible I don't have enough oil and that that is the cause?



I don't think I even added 1/2 a quart more than what was in there before the oil cooler.

Anyone interested in buying an oil adaptor and cooler :D ?
 
"I?m not familiar with Terry?s adapter but I assume there is a piece that fits down in the oil port of the engine. Check to see if the top of the piece is flush with the top of the oil cavity ? if the piece is sitting down in the cavity, there will be bleed off when the top plate is installed."

The little adaptor that comes with the plate seems to only fit down into the oil cavity. There is a picture of it in one of Cafe Kids threds.

But putting it down in the cave leaves the top fush with the adaptor plate. I'll see of I can find that picture and put a link.
 
ryonker said:
The little adaptor that comes with the plate seems to only fit down into the oil cavity. There is a picture of it in one of Cafe Kids threds.

But putting it down in the cave leaves the top fush with the adaptor plate. I'll see of I can find that picture and put a link.
Click to expand...

The depth of the oil port varies from one engine to another, it's best if you use a straight edge across the top of yours while the adapter is installed to varify it's flush with the top and you are not getting bleed off.
 
You must log in or register to reply here.
Back
Top