The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: JJH on April 01, 2015, 10:54:26 AM
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Hi I just joined and would like some advice on a problem I am having with my new (for me) bike. 1979 r65, about 21000 miles, but the last owner only drove it 500 miles in 15 years. So really just sat around mostly. I took it out on its first "long" ride, ~15 miles and towards the end the oil pressure light came on at idle. I fixed that by just keeping the rpm's high at the last couple of stops. The next time I took it out the light came on when I was actually riding. I pulled off, turned it off. Restarted rode awhile, light on, stop, start repeat. I posted on boxerworks and with their advice I pulled the oil filter and checked for the oil ring/ shim/ gasket. It was incorrect, so I put in the correct number of shims and started up, but the same behavior happened. I was given the advice to drop the pan and look at the screen, and/or put a oil pressure gauge to find out what the oil pressure actually is. I don't have an issue with either of those suggestions, but was wondering if any of you had this issue and what worked.
Thanks,
John
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Before you rode the bike you replaced the oil and filters with new..I hope ?
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The first thing you need to do, is to determine if the oil pressure is actually low, or if it is a false indication from the low oil pressure switch .
There is an oil filter bypass valve in the cavity that has the oil filter, it's at the far end, it is a small silver ball that has a spring behind it .
The oil pressure regulator is in the area of the timing chain at the front of the engine, not so easy to get to .
This most likely is not causing the probelm you have now with the oil pressure light, but it's not uncommon to have the insulation on the oil pressure switch wiring get brittle and break off leaving exposed conductor of the wire .
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The oil was, I did not change the filter until the oil pressure light problem. Previous to the "long" ride, it was just around the neighborhood and parking lots and the light did not come on it those rides.
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At least 9 times out 10 low oil pressure is going to be down to filter installation so your problem is unusual.
I'm not sure how the pick up in the sump could cause low oil pressure. No oil pressure yes but unless it's seriously blocked not low pressure. That leaves the oil pump which is even more work to investigate than dropping the sump. There is a filter bypass valve and a high pressure valve that bleeds off excess pressure to lube the timing chain but I cant see how either could cause the very low oil pressure that would bring on the oil lamp. So I think the advice to fit a gauge was good as then you'll really know if you have a serious problem or not. The pressure switch is set very very low so for that to come on and it not be faulty indication means there is definitely something wrong. The pressure gauge will tell you what's happening. Expect 20-30psi at idle and 70 PSI when you rev it.
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Bob, when I pulled the filter to replace it, I saw the little ball valve. The ball was there and the ball was in the center, but as for it being "correct" I'm not sure I would know what it was supposed to look like.
To clarify, before I ever rode the bike, I changed the oil but not the filter. I have now changed the oil and the filter ensuring the correct number of shims are in place
Thanks,
John
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John,
The little ball valve you see when changing the filter can have little or no impact on oil pressure as even if it was open all the time it just means the oil bypasses the filter. If anything the pressure would go up a little.
The only reason to inspect that valve by giving it a little prod is to make sure the spring is not broken because bits of broken spring have been know to ruin the bearings. What it should feel like when you prod it with say a chopstick is a very light spring.
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Was the white o-ring slightly deformed/squished?
Did you measure the canister depth? Its not about the number of shims, but about the correct "squish" of the gasket (perhaps that is what you mean)
http://www.largiader.com/tech/filters/canister.html
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I think from what I've read, John is very confident that O ring compression is not the problem.
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When I removed the filter for replacement there was one shim and o-ring. The o-ring looked really good and not smashed (which I guess is actually a bad thing). Anyway prior to replacement I checked the o-ring website(s) and measured the canister depth. It was deep and calculated the correct number of shims was 3 without a paper gasket. When I replaced the cover I could feel a slight compression when tightening the screws.
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Now that my memory got stirred up, I had this happen on my '81 R65 right after I changed the oil and filter .
Bike was still under warranty got the bike back to the dealer, when I went to pick the bike up a week later, I asked what they did .
The response was, they put compressed air in the long tube that the oil filter goes over and ' reset ' the oil pressure regulator, I was skeptical, it seems to have worked .
That was 33 years ago and hasn't happened since .
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Be sure the shims went in before the O-ring. Their actual purpose is to prevent the O-ring from being cut by the edge of the filter canister.
With the three shims and a new O-ring, have you taken a test ride to see how the OP lamp is working? No lit lamp would be a good thing.
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Montmil- The shims went in directly after the filter. They "sat" on the filter canister.
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Bob's early experience with his bike sounds an interesting possibility as a cause of low oil pressure. It implies that the relief valve was stuck open even though the set pressure is normally 70 PSI
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I have a question, how long is the center pipe that the filter fits on in a 1979 r65? Does it extend the entire length of the filter?
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My '81, the original tube from what I remember was about 2 inches long .
I installed an oil cooler kit and there was a new tube that went all the way to the filter cover .
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I've never measured it but on my 79 I'd say the pipe is a little less than 2" it's Just long enough to locate the filter on.
The oil flows from the main filter tube through the filter from the outside to the inside and out of that pipe into the oil galleries.
I supposed at first that if there was blockage in that pipe it could reduce oil pressure but on reflection it wouldn't as the oil would just see it as a blocked filter and go through the bypass valve instead.
Have you seen the attached description and diagram of how the lubrication system works. I've added the diagram as a separate image as it's much higher quality allowing you to zoom in and really see the detail.
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The symptoms you describe sure sounds like a faulty oil pressure switch
I am not sure but doesn't the switch out of a Volkswagen fit it or something like that.
What part of Mo are you in.
I would think Engels in KC or Gateway in St Louis would have the switch in stock
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Two items to be aware of, if considering utilizing the Volkswagen OP sender switch:
1. Threads on some of the switches do not match the BMW crankcase threads.
2. Confirm that VW's OP switch activation pressure matches that req'd for the Airhead.
No concerns with using OEM switch.
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Assuming that you installed the filter correctly, have the right oil volume in the bike and have no obvious oil leaks, then its most likely to be the wiring to the switch or the pressure switch its self at fault. A new pressure switch is only about £10 from Motorworks.
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Just a thought and simple things first but what weight oil did you put in it?
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I could not find the correct OP switch at the local auto parts store. The VW ones had smaller threads M10 X 1.0 not the M12 X 1.5 No one had the oil switch for the BMW 2002 in stock. On another note, I bought a cheap oil filter tester from Harbor Freight. I carefully removed and very carefully screwed in the tester. I barely snugged up the tester. I started the bike and at idle it rad 90 psi and when revved it was over 140 psi. Now Harbor Freight only sells the cheapest and low quality tools available anywhere in the world, so I wasn't too surprised by the values. But one thing to note the oil was pumping at a great rate from the tester. I tightened it up a bit, but it still leaked from the oil pressure switch hole. What this indicates to me is there is more than 3-5 psi being generated (I think that is the cut off for lighting the oil pressure switch). I removed the tester and placed the oil pressure switch back in. I started the bike and after ~15 seconds the oil pressure light came on, when I revved the engine it went off, when back at idle it came back on weakly.
I am travelling to the city for holiday tomorrow, and will be stopping off at the dealership to pick up an oil pan gasket and a new oil pressure switch. Is there anything else to pick up to help me trouble shoot this problem?
Thanks,
John
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From what you describe it sure does sound like it's just a faulty switch. Your HF tool might be cheap, but it's not going to be off by 80+ psi.
Before you worry any more about it, I'd just put the new switch in and see how it behaves.
Also, I assume your GEN light is regularly coming on at idle as well? I can't recall if they have the same bulb, but maybe it's possible that the GEN light and OIL light got swapped if you're not seeing the GEN light
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That is what I am starting to think. It is definitely the oil light. The gen light comes on at idle and fades at higher rpms as it should do.
Thanks,
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Confirm dash lights are in their correct bulb holder by checking the wiring diagram for wire color-codes.
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Well whatever it is you must be mightily pleased it's not a major problem after the oil pressure test. The original switch spec. is 0.2 - 0.5 bar or approx. 3 - 7 psi. Seems to me the damage is done at 3 psi and if I was looking for switch within reason I'd pick the highest pressure I could find.
Here's an oil pressure switch catalogue that might give you some part numbers to search for.
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Don't be surprised by the oil pressure you saw on the test indicator, these bikes have lots of oil pressure .
It doesn't happen too often, but owners of airhead BMW bikes have found collapsed oil filters when they change them .
Go easy on the throttle in cold temps, pressure can easily exceed 150 psi on first cold start up .
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Remember 20W50 is darn thick oil when it is cold
To really know what is happening you need to check the pressure after it is fully warm.
That pressure will come down when the oil gets up to operating temp.
I really think you just have a faulty pressure switch.
Put a new oil pressure switch in it and see what happens. :D
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Well I installed a new oil pressure switch and took the bike out for a few runs and no oil pressure light. So I guess it was a faulty sensor. Thanks for all the help that you provided.
John