spfksfdk Posted December 15, 2008 Share Posted December 15, 2008 Hi Folks, Rode home on Thursday and all was well. Started the bike to go to work on Monday and the oil light came on! Just changed the pressure switch (and it's freezing out there) and the light is still on :-( The new switch is actually second-hand.... but from a reputable supplier. How can I check the sensor? The bike is an 2002 R1150RT with 85000 miles. If I short the two wire going to the switch, should the light go off? Gonna have to drive the car again tomorrow :-(( Link to comment
T__ Posted December 15, 2008 Share Posted December 15, 2008 Hi Folks, Rode home on Thursday and all was well. Started the bike to go to work on Monday and the oil light came on! Just changed the pressure switch (and it's freezing out there) and the light is still on :-( The new switch is actually second-hand.... but from a reputable supplier. How can I check the sensor? The bike is an 2002 R1150RT with 85000 miles. If I short the two wire going to the switch, should the light go off? Gonna have to drive the car again tomorrow :-(( Andrew, Well the oil pressure switch should trigger at about 4.5 psi (actually 4.35 psi) so you can use an ohmmeter & a pressure source (air pressure) to test it.. Sounds like time to install a pressure gauge on the oil switch tap at the engine then verify you have enough engine oil pressure.. It won’t take long to damage your engine if the oil pressure is in fact low.. What oil switch did you change out? You are talking 2 wires & that would more than likely be the oil temperature switch (up behind the alternator).. The switch that controls the oil light (single wire) is on the lower L/H side of the engine down by the sight glass.. Twisty Link to comment
spfksfdk Posted December 15, 2008 Author Share Posted December 15, 2008 Doh! Just got back in from the cold to find your reply, yes I changed the temperature sensor... Nuff said, must be the cold! I pulled the wire on the pressure sensor and the light goes out, shorted it to ground and the light comes on, connected it back to the switch and the light is on, even when the bike starts. Link to comment
ragtoplvr Posted December 15, 2008 Share Posted December 15, 2008 I would unscrew the switch, go down to my trusty local auto parts store. Look at the mechanical oil pressure gages, make sure it has an adapter that will fit the switch. Buy gage, install and then you know exactly what it is doing. Should cost less than $25. Cheapest part you will ever buy for it. cold you should see at least 40 PSI , max should be around 80. Hot idle still should be 10 or so as a minimum. You can even tape the gage to something to look at while you ride. Just don't crash from looking at gage. If pressure falls when increase throttle that is sign of worn bearings. If all is well then you need a pressure switch. Please post back findings. Rod Link to comment
T__ Posted December 16, 2008 Share Posted December 16, 2008 Doh! Just got back in from the cold to find your reply, yes I changed the temperature sensor... Nuff said, must be the cold! I pulled the wire on the pressure sensor and the light goes out, shorted it to ground and the light comes on, connected it back to the switch and the light is on, even when the bike starts. Andrew, more than likely a bad oil light switch (or more likely some moisture frozen in the small switch orifice).. (Maybe pull the sensor switch & heat it then blow it out inside) Very seldom would an engine even with bad bearings show low oil pressure on a very cold start (as a rule worn bearing & other worn engine parts will bring the oil light on hot not extremely cold as the oil is just too thick when cold).. Exception here would be excess water in the oil that is frozen so the oil pump can’t move it or the ice blocks the pump inlet screen.. Twisty Link to comment
spfksfdk Posted December 16, 2008 Author Share Posted December 16, 2008 Thanks twisty, I may try that tonight. Just ordered a new switch and paid half as much again to make sure it arrives tomorrow, I soooo miss riding to work, even when it's cold! Link to comment
Unhofliche_Gesundheit Posted December 16, 2008 Share Posted December 16, 2008 question for the experts - how are the oil pumps and pickup screens for reliability? how likely might they be to be the cause of the trouble? (some bikes are very poor in this area from what i can tell by reading motorcycle mechanic magazine - which tends to focus on Japanese bikes only unfortunately ) Link to comment
SageRider Posted December 16, 2008 Share Posted December 16, 2008 What weight oil is in the crankcase? How low are the temperatures? Link to comment
Paul Mihalka Posted December 16, 2008 Share Posted December 16, 2008 I think if you really had a engine with so low oil pressure that the light is on solid, first you would hear a terrible racket and then have a dead engine. Link to comment
T__ Posted December 16, 2008 Share Posted December 16, 2008 question for the experts - how are the oil pumps and pickup screens for reliability? how likely might they be to be the cause of the trouble? (some bikes are very poor in this area from what i can tell by reading motorcycle mechanic magazine - which tends to focus on Japanese bikes only unfortunately ) Cameron, only the BMW mother-ship would know the true answer to that question but you very very seldom if ever hear or know of a BMW boxer lower end failure,, & even the few that do they don’t seem to be from oil pump related problems.. Pretty simple & straight forward oiling system in the BMW oilhead with twin pumps,, one for engine oiling & one for cooling,, adequate oil passage sizes,, decent inlet screening,, & fairly decent filtering .. Twisty Link to comment
spfksfdk Posted December 16, 2008 Author Share Posted December 16, 2008 Temperature is only -2 ish. When I remove the switch, should any oil come out? Link to comment
T__ Posted December 16, 2008 Share Posted December 16, 2008 When I remove the switch, should any oil come out? Andrew, only a little drip.. The switch is above the oil level so about all you will get is a little drain back from the oil channel above the switch.. Twisty Link to comment
Ken H. Posted December 16, 2008 Share Posted December 16, 2008 question for the experts - how are the oil pumps and pickup screens for reliability? how likely might they be to be the cause of the trouble? (some bikes are very poor in this area from what i can tell by reading motorcycle mechanic magazine - which tends to focus on Japanese bikes only unfortunately ) While not unheard of, oil pressure problems, from any source, are exceedingly rare on the boxer motor. Link to comment
spfksfdk Posted December 17, 2008 Author Share Posted December 17, 2008 Postman just arrived with my new switch... Fitted it and switched on the ignition, Red_Light = ON Fired-up the bike, Red_Light = OFF Result - One very happy BMW owner, who WILL be riding to work tommorow :-) Thanks for all you help. Link to comment
AndyS Posted December 17, 2008 Share Posted December 17, 2008 Postman just arrived with my new switch... One very happy BMW owner, who WILL be riding to work tommorow :-) Thanks for all you help. Nice to see. Glad all is sorted. Link to comment
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