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oil pressure switch

Posted: Fri Nov 09, 2007 7:59 pm
by xrphil
anyone changed the oil pressure switch, mine seems to be playing up.
cant find one on the parts drawwings, can i use one from another bike? or even a car,(they seem the same) or are they an Aprilia item.
anyone know how much they cost.

Posted: Fri Nov 16, 2007 2:33 pm
by loafersmate
I changed mine a few weeks ago since it was leaking out past the blade connector! It was £11.02 delivered from speedaway, part number 0956169.

Posted: Sun Nov 18, 2007 2:22 pm
by xrphil
cheers, got one from in moto (£10.37 inc P&P)
unfortunatly this turned out not to be the problem. wiring seems OK also.
problem is that oil low pressure light comes on at about 2000 rpm (which on mine is tickover until i get round to turning it down a bit.)
the problem started after i last serviced it, this included an oil and filter change.
I took the oil filter back out this AM, and it must had been fitted at a slight angle as it is a bit sqaushed on one side, not badly but i stuck a new one in and thought that maybe it.
took her for a spin, as it only happens when the oil is hot, and it seems a bit better, but is still doing it.
doesnt come on at tickover so much but does if you stick it in gear and drop the revs a bit with the clutch.
any ideas what maybe causing this, i have looked through old posts, but only thing that came up was something about a sticking pressure relief valve?

Posted: Sun Nov 18, 2007 6:05 pm
by loafersmate
or a worn oil pump, if it only happens when the oil is hot (thin) then the pump may not be able to create enough pressure at low rpm.

Posted: Sun Nov 18, 2007 8:10 pm
by xrphil
did wonder about that but at 14000 miles! with reg oil changes.
also strange that it started doing it after an oil change, though oil would then be thinner. (i think)

Posted: Sun Nov 18, 2007 8:33 pm
by Kwackerz
The oil level is correct? :smt017

Posted: Sun Nov 18, 2007 8:37 pm
by D-Rider
Well sorry to state the obvious and risk insulting intelligence ... but I guess it has got enough oil in there .... as checked by the strange official Aprilia method?

Sorry if this is too obvious ... but the number of times I've had a problem and found it was something blindingly straightforward ....

EDIT .... and Kwackers has just beaten me to the post!

Posted: Sun Nov 18, 2007 8:58 pm
by Kwackerz
:smt002

Posted: Sun Nov 18, 2007 10:20 pm
by xrphil
yea, had to much if anything, had to take some out, was my first thought when i saw it come on!
did seem a little better this afternoon, didn,t come on at tickover only on the bite with clutch, or first few secs after starting.

Posted: Mon Nov 19, 2007 9:24 am
by fastasfcuk
what oil have you put in. :smt017

Posted: Mon Nov 19, 2007 1:07 pm
by HowardQ
D-Rider wrote:Well sorry to state the obvious and risk insulting intelligence ... but I guess it has got enough oil in there .... as checked by the strange official Aprilia method?

Sorry if this is too obvious ... but the number of times I've had a problem and found it was something blindingly straightforward ....

EDIT .... and Kwackers has just beaten me to the post!
Sorry Andy but accurately checking the oil level on a Falco is never somethingthat I would call "Blindingly Straightforward"
:smt003 :smt003 :smt003 :smt003 :smt003 :smt003 :smt003 :smt003 :smt003

Posted: Mon Nov 19, 2007 4:54 pm
by Fausto
Isn't there some issue re the oil filter changing shape/size recently?

If so - is it at all possible that you have the wrong one and it isn't fitting properly ?

Posted: Mon Nov 19, 2007 5:03 pm
by D-Rider
Fausto wrote:Isn't there some issue re the oil filter changing shape/size recently?

If so - is it at all possible that you have the wrong one and it isn't fitting properly ?
Yeah - it's a "sticky" on the Aprilia Technical pages:

CLICK HERE

Posted: Mon Nov 19, 2007 10:22 pm
by xrphil
I,ve checked and i still have the old pt no oil filters. oil 15/50w as before.
the problem only occurs when the oil gets up to temp, and only around 1500 RPM, then it goes.
looking at other forums its seems to happen after people have done an oil change.

Posted: Mon Nov 19, 2007 11:37 pm
by loafersmate
If the switch is definitley ok, the oil pressure can only be too low if:

a, the pump cannot make enough pressure at low rpm, ie clearances are too big in the pump
b, there is a leak in the pressure side of the system,
c, the pressure relief valve is set too low or the spring has 'gone weak'

I can't see the filter being fitted incorrectly causing the problem unless it was blocking one of the galleries partially. The only way to know for sure is to get a low pressure guage plumbed into the oil pressure switch port, the thread is m10x1, and check it against the manual.