Oil light on a 16' GRiSO

Hello all,

Just curious if anyone else has had the "SERVICE" /low oil light come on with their 8v? I have a 16' (only 1600 miles) which has had the light come on 3x now at different times, all when starting the bike. Cut the bike off, cut it back on the light goes out. Also, it comes on before the bike is actually started. My oil level is correct but still a little confusing/concerning. No funny sounds, smoking exhaust, etc. Runs fine. Thoughts?

Thanks,
Chris

Bad oil pressure sensors are fairly common. You might want to check the connector on the sensor, they are a common issue as well.

Thanks, other than catastrophic failure...is there anything that may indicate a faulty oil pump over just a faulty sensor given what I've described?

Most likely not an oil pump. As Beetle says the connection to the oil pressure is the most likely culprit. The original type had a screw out connector, I replaced mine with a 45 degree 1/4" quick connect tab and a small metric screw (3mm from memory, but don't trust me on this). Haven't had a problem since.

It might be the oil pressure sensor, too, so small steps at first.

Pete may be able to provide a more in-depth answer, but an oil pump failure would provide a constant light, probably be noisy, followed by the "dogga dogga dogga" sound of your big-ends in their death throes.


Another uncommon but known issue, is that of the internal gasket falure. It can cause this to happen as well.


I wouldn't ride it until you've investigated.

Yes, definitely find out why it’s illuminating and fix it. It is in all likelihood just a dodgy pressure sender switch as these have always been an Achilles heel but if it is something more serious it is likely to be a lot more serious.

On earlier, pre-2014 or so bikes the spacer gasket between the sump spacer and the block was fragile and barely adequate and this occasionally led to the gasket blowing out on one of the delivery galleries dumping oil back into the sump and diminishing pressure to the point the light would illuminate. This is really worrying because the switch only operates at some incredibly feeble pressure and by the time it’s on it’s usually too late! It’s a tribute to Guzzi toughness that the usual first sign of this having occurred is the cam chain tensioner plungers not pumping up so the chains rattle! The big ends tend to survive, for a while!!! In 2014 or so a thicker, more substantial gasket with more crush was introduces and the problem went away.....BUT! (There’s always a ‘But’!)

From 2015 Grisos have used the Cali 1400 sump which doesn’t have a spacer. The filter, OPRV and oil delivery tubes are all contained on/in another casting internal to the sump that bolts onto the crankcase. This system also uses gaskets to seal of course and the ones I’ve seen seemed to be made of the earlier, less robust, material but I’ve not previously heard of and indeed have never seen them fail.

Oil level/quantity has nothing to do with the light/service warning illuminating. It’s all to do with pressure. As long as there is enough oil in the motor to cover the pick up it shouldn’t illuminate so don’t fret on quantity. It is important though that you isolate what the problem is and fix it because if it is something more serious than a dodgy switch I’d does have the potential to kill your engine in just about the most expensive way possible.

Pete

Thanks Oz, Beetle and Pete for the thoughtful responses. My bike is definitely under warranty still as I've only had it about 6 months. In fact, Tampa Eurocycles just replaced my final drive due to a leak that they couldn't fix. Piaggio just sent them a brand new final drive to replace mine after replacing some sort of boot that didn't do the trick. Guess it goes back for a diagnosis on the warning light. Considering how well my bike runs, I imagine it's just electronics but it won't hurt to double check. I'll let everyone know what the outcome is once I know more.

Thanks!

I think this is a bad oil pressure sensor as my oil/service light came on today (both times it went off when shut down and restarted - not low on oil). I've heard there is a non-Guzzi replacement sensor that may work better. Does anyone know what the part number is and where to get it? Napa maybe?

The only one I know is a locally sourced part here in Oz for the earlier CARC bikes which is a Tridon TPS 039 from memory.

Just take the current one in to a decent parts place with a good interpreter and they should have a catalog and you can match it up. The important things are thread pitch, connector type, crack pressure and whether it is open or closed at rest. You want one that is closed at rest and crack pressure of 5-8 PSI.

PETE

Thanks for the tip Pete. I'll work on it in the next week or so and report back-

Just a quick follow-up. Got my bike back from Tampa Eurocycles this week and they said the oil pressure sensor wire was "crimped" causing the oil light to come on some of the time. Said they adjusted and it's fixed...So far so good.