Leaking oil below the alternator

Squinternotto Posts : 5 Join date : 2024-01-04

Hello GRiSO owners, I’m interested in buying a 2013 GRiSO and was able to confirm that the bike has roller tappets by opening the valve cover. After inspecting the bike, just below the alternator, at the upper left front (shifter side) of the motor where the little sensor is bolted onto the block, that area including the sensor is very wet with oil, under the tail end of the air box is also wet. The bike only has 10,000 miles. I’m really interested, but should I be concerned, and do you guys have any idea where the problem might be coming from. I appreciate very much the help and advice I can get. Many thanks to all of you!

GRiSO Capo Posts : 1471 Join date : 2015-01-04 Age : 63

It's not unusual for oil leaks near front blowby oil separator - either failure of the 'condom' on the separator (see picture) or cracks in the associated rubber linework going in/out. My 'condom' had a small hole in the end from rubbing against the cables/pipes next to it & leaked load of oil down over the alternator directly beneath

Not hard at all to fix if that's the cause.....

[You must be registered and logged in to see this image.]

BTW it can easily spread backwards (faster you go the further it spreads) along the blowby lines back to the rear of the heads & into tail unit.

GRiSO Capo Posts : 10420 Join date : 2013-05-29 Age : 67

Also the phase sensor, (The one you mention at the front upper left of the timing chest.) can leak. They are sealed with an o-ring which hardens and allows leakage. Just remove the sensor, being careful not to loose the shim/s underneath it and replace the o-ring and seal the area around the sensor with a thin smear of Threebond 1211..

Oil around the back of the airbox is most likely the result of overfilling of the sump and also the drain hose from the back of the airbox may be broken or missing. There are two drain hoses from the airbox. One central at the front on the bottom of the box and one at the rear on the left hand side. Both are prone to hardening and failure. It is vital that these hoses be fitted, sound and plugged at the bottom where they hang under the bike by the RH footpeg hanger plate. If the hoses are missing, broken or unplugged it allows the ingress of dirt to the airbox and rapid damage to the throttlebodies will occur.

Squinternotto Posts : 5 Join date : 2024-01-04

Many thanks Pete and Paul for giving me some very important tips and advice. Because of the “knowledge” you guys are willing to share to people in this forum makes buying a used Moto Guzzi much easier and convenient!
Many thanks again to both of you!

» Alternator output went up???
» Alternator 07 GRiSO interchangabitity?
» Alternator works?
» Alternator Belt
» Alternator belt replacement