low pressure oil light on at idle

[mobetta]

HI everyone,

after changing oil on my 2004 V11 ballabio initially everything seems fine, after roughly 10 KM when the engine warmed up the oil pressure light came on at the idle on the lights.

To change oil I dropped the pan and install new HiLo filter and filled up with Motul 300V 5W40. There is no leaks and oil is up to capacity.

Would appreciate any pointers where to start to look for a problem. 

[docc]

There have been instances of the old filter gasket staying on the motor when the filter came out.  Absolutely worth checking!

5W-40 seems a might thin for a motor that commonly runs on 20W-50, but I can't imagine that could be the source of low pressure at idle . . .

[LowRyter]

I would think heavier oil would made for more pressure.  Could it affect pressure at low rpms when warmed up?  If that was the only change you made, that could be the culprit.   

I thought all Guzzis from the V11 era used 20-50.  

I don't think that that Sport engine has the same issue with backwards (upside) down pan gaskets that the EV has which will definitely get an oil light.

[mobetta]

Thx docc and LowRyter for reply,

will definitely drop the pan and investigate. The owners manual calls for Agip Racing 4T sae 5w-40 which is no more available, any suggestions for replacement?

[footgoose]

Also what rpm do you have at idle. Don't recall what's called for 1100?

[docc]

22 minutes ago, mobetta said:

Thx docc and LowRyter for reply,

will definitely drop the pan and investigate. The owners manual calls for Agip Racing 4T sae 5w-40 which is no more available, any suggestions for replacement?

Ah, yeah, sorry for my oil weight comment. I recall now that Moto Guzzi changed the spec on the later V11.  Your Motul is likely just fine.  Personally, I'm a RedLine fan; true Group 5, full ester base oil. Awesome stuff. Oil? we can go on-and-on, of course.

footgoose makes a good point about idle speed. The tachs can read high (early Veglia as high as 300-500 rpm) which could lead us to try and idle at 700 rpm - not good.  That, alone, might save you pulling the sump!

If you still have the filter you took off, you can inspect it for the seal.

 

[mobetta]

Idle speed is 900-950, low oil pressure light comes on when tach drops below 1200. Any chance in blockage in oil radiator or oil lines?  Once again I appreciate all the comments.

 

[docc]

Blockage not likely. Loose filter or double seal more likely.

Wouldn’t hurt to bring your idle up. The spec is 1050+/-50 IIRC. I like mine on the high side + , partly to move more oil at idle.

Do you have guzzidiag? This way you can check the accuracy of the tach. If yours is reading high (not uncommon), you could be trying to idle at a true 600-650.

(Still worth inspecting that filter IMO ....)

[pete roper]

Replace the oil pressure sender switch, they are always suspect. Drop the sump spacer and the carrier for the filter, thermostat and OPRV, check OPRV is working correctly and replace gasket, (Also a good time to fit a sloppage sheet if you haven't already.) raise the idle to 1200+/-50.

[Lucky Phil]

2 hours ago, mobetta said:

HI everyone,

after changing oil on my 2004 V11 ballabio initially everything seems fine, after roughly 10 KM when the engine warmed up the oil pressure light came on at the idle on the lights.

To change oil I dropped the pan and install new HiLo filter and filled up with Motul 300V 5W40. There is no leaks and oil is up to capacity.

Would appreciate any pointers where to start to look for a problem. 

Re check your work esp the filter fitment. The 5W-40 isn't too thin as the CTS at 100deg C is still the 40 weight equivalent which is adequate. I've run my bike on 0W-40 Mobil1 for 10 years with no issues.

Other things to consider, an oil pressure relief valve that's not seating correctly(you can disassemble it insitu and clean it) the  a LOP switch that's not the correct part (they differ in their thresholds) although they fit and maybe your engines close to the lower limit on oil pressure at hot idle. As Pete pointed out it's probably time to swap out the switch anyway.

Having said all that I had a friend years ago that had the same issue on a Mk4 Le Mans after changing to a lower grade oil and he solved the problem by going back to a 20W-50. It shouldn't really be necessary but the 20W-50 can band aid over other issues and if the bikes running ok then that's fine for some people. The 50 weight gives you a little more hot oil pressure headroom on the switch setting. 

Ciao

[LowRyter]

My buddy Darren had a 1200 Sport (Breva).  The service tech used 20-50 rather than the required 10-60.  He got the pressure light and had to go back for a change.  I'm of the opinion, "likely excuse for a loose filter" but what the heck, that's the story.  He had it changed to 10-60 and the light went out.

Again, I had no idea that these engines used anything but 20-50, so if it's the right weight, never mind.  (It was a stretch anyway.)

Still, since it occurred after the oil change, I'd suspect something in regard to that.  

[gstallons]

You do NOT want to ruin an engine , be deliberate and be careful

[pete roper]

43 minutes ago, LowRyter said:

My buddy Darren had a 1200 Sport (Breva).  The service tech used 20-50 rather than the required 10-60.  He got the pressure light and had to go back for a change.  I'm of the opinion, "likely excuse for a loose filter" but what the heck, that's the story.  He had it changed to 10-60 and the light went out.

Again, I had no idea that these engines used anything but 20-50, so if it's the right weight, never mind.  (It was a stretch anyway.)

Still, since it occurred after the oil change, I'd suspect something in regard to that.  

One of the occasional bugbears of the CARC bikes is the gasket between the spacer and the block blowing out around the delivery gallery at the front. Easily fixed by fitting a thicker aftermarket gasket it seems to affect the 8V's more than the pushrod engines but the result is a significant loss of pressure.

[LowRyter]

39 minutes ago, pete roper said:

One of the occasional bugbears of the CARC bikes is the gasket between the spacer and the block blowing out around the delivery gallery at the front. Easily fixed by fitting a thicker aftermarket gasket it seems to affect the 8V's more than the pushrod engines but the result is a significant loss of pressure.

Similar thing for my EV (as I mentioned).  The gasket was upside down on the silly spacer.  Oil light went off when it was revved but stayed on at low rpm.  That's when I was learning to service the bike 10+ years ago.  That's not an issue with these motors.  I didn't know it was a CARC thing too- I'd bet that was Darren's deal rather than 20-50 oil.  

[mobetta]

Thx Everyone fro pointers, will drop the pan and check the fitting of filter and gaskets, will report results when done. Cheers !