Oil pressure gauge response to heavy acceleration or braking?

[Guzzi-in-Vancouver]

So yesterday I had to do an emergency stop at a pedestrian controlled light. I could’ve gone through but figured I’d been practicing, so here was a chance to get some honest practice in a more “earnest“ situation. 

Anyway, a screech and a skid later, as I sheepishly but proudly walked the bike a half foot back and reflected on mayhap having grabbed the clutch a tad bit, I noticed the oil pressure gauge had lit up. I took it as a bit of a finger wagging from my Italian mistress, excessively tickled by the throttle perhaps…

Except, she was mad at me all the way home for another ten minutes! Is this something I need to worry about or is the oil pressure gauge somehow triggered by heavy acceleration and braking?

[docc]

The oil in the sump can "slosh" and uncover the pick-up, especially if the oil level is low. Check that first and report how far down the stick it is.

Otherwise, this is the reason there are "Roper Plates", or in today's parlance, "The Rusty Star Picket Project" . . .

[guzziart]

Were/are all the Roper plates engraved? ....just curious, it's a nice touch!  I have one in my Lemans that was installed by the original owner, I haven't ever taken a close look at it.

[Pressureangle]

11 minutes ago, guzziart said:

Were/are all the Roper plates engraved? ....just curious, it's a nice touch!  I have one in my Lemans that was installed by the original owner, I haven't ever taken a close look at it.

They are not. We did a few to start, but the stainless material and our engraving machine didn't like each other very much. To send them for laser engraving would have added to the cost.

[Pressureangle]

docc, do you need an engraved plate for your wall? I can probably make that happen before September.

[docc edit/reply: Absolutely, @Pressureangle! I am all about supporting , and archiving, the community efforts. Just don't let it be a burden to perform that just for me.] (Odd way to reply, I know, but meant to avoid drifting @Guzzi-in-Vancouver's important thread.)

[Scud]

19 hours ago, Guzzi-in-Vancouver said:

I noticed the oil pressure gauge had lit up. 

...she was mad at me all the way home for another ten minutes! Is this something I need to worry about or is the oil pressure gauge somehow triggered by heavy acceleration and braking?

Do you have an added oil pressure gauge that shows the pressure, or just the standard oil warning light on the dash? (It sounds like you have just the light or you would have told us the oil pressure in numbers).

And do you mean you rode the bike for 10 minutes with the oil pressure warning light on? And if so, did it eventually go out?

Assuming your oil level is correct and your filter is still on tight, you might want to test the actual oil pressure with an external gauge.

 

[pete roper]

If this happened under extreme braking it is unlikely to be pressure loss due to pick up exposure. The pick up on the 'Broad Sump' motors is at the front on the right of the sump. Under heavy braking the oil will slosh forward and there is little chance of it being exposed. It's on hard acceleration, and especially if you wheelie it, that the pick up is likely to be uncovered.

In this case, if I'm interpreting the OP correctly, the light remained on for ten minutes after the event during which time the motor was running and the bike was being ridden. If there had been a catastrophic loss of pressure the crank would be toast. Plain bearings simply can't survive without a constant supply of oil at the correct pressure. We are talking seconds, not minutes for irreparable damage to occur.

That leads me to think it is far more likely that the cause for the light coming on is far more likely to be something as simple as a dodgy switch, (A well known and documented issue.) or even simply the connector on the wire that goes to it being loose and just the inertia of the cable hurtling forward as the brakes were applied may of caused it to slip and break the circuit.

I'd still suggest the installation of a sloppage sheet as it really is very cheap protection for your crank but in this case I don't think it would of helped.

[Guzzi-in-Vancouver]

Thank you all, and to clarify, yes the Roper plate is on the bike, there was some hard acceleration and braking, but no wheelies. I remember the light being on for a few seconds after I stopped at the light (directly after the hard braking) but I drove slowly for a bit and it went away, though not immediately, and I wasn't diligent in checking on it. I rode the bike again the next day and there was no light. So I don't suppose it was a loose or disconnected wire.

I will check the oil level, it was refilled during a recent service but I suppose the shop only put in the standard amount. Does adding the Roper plate call for more oil? I read a thread about drilling the dip-stick, and then another about a similar oil-gauge situation that was traced to a loose washer on the oil filter... since mine was recently replaced I should get it checked.

[Weegie]

I'd get an adapter which screws into the oil pressure switch tapping and allows a gauge to be installed and put a gauge in.

You could do that simply as a temporary test or permanent install, it would give you some idea of what is actually happening.

I don't own a V11 but have a Sport 1100i and HiCam which both have broad sumps and run the oil level to just below the level of the plate, which is a lot more than the Hi mark on the dipstick without issue, but AFAIK there is no real reason to do that and the V11s are fine with the recommended amount of oil.

Were you running in a lot of traffic or stop/start prior to this and when the light came on was it at idle (I assume it was)? Idle pressure is way lower than above 2k rpm and higher still at 3k rpm but then plateaus. Wondering if the switch was a bit sticky and activated but didn't reset when it should.

If the engine gets very hot due to low speed/traffic/log periods at idle high engine temp can result in thin oil and pressure dropping which may exacerbate the situation. That said my experience is the 2v/v bikes are far more robust and don't usually have an issue with low pressure.

Checking the filter is an easy job, but messy, if you've just changed oil, or aren't due a change you can drain it into a clean container and reuse, although for all the cost I refill with fresh oil.

You could check the filter for looseness and the gasket for either none or doubling and get a Roper plate installed, cheap and work great.

[Rolf Halvorsen]

The 1400 models uses a steel reinforced bottom gasket - to prevent a "blow out" of internal oil - resulting in loss of oil pressure.

This gasket has No: B063861

I will advise this gasket to be used on all big Guzzi's from 1965 and up.

[Weegie]

@Rolf Halvorsen

Looking at that gasket it would be the one that sits between the oil sump internal pipework/upper spacer face and the crankcase.

Are you recommending its use due to issues with the standard paper gasket deforming or blowing out resulting in loss of pressure on the oil circuit's feed to the sump?

I've heard of problems with either poorly installed or badly made gaskets causing pressure drops, but never of blowouts, so I'm curious.

John

[Scud]

I chased a low pressure situation for a while on a 2003 LeMans. Turned out that part of the gasket (as pictured in Rolf's post) was missing. This internal leak allowed oil to escape but maintained low pressure - the light would sometimes come on at idle, but would always go out with a blip of the throttle. It ran like that for a long time without any failure, but I did find excessive wear on the washers on the rocker-arm shafts.

The problem with the warning light is that it only tells you about dangerously low pressure. If you care for a lengthly and somewhat philosophical exchange about this issue, see my topic about it at: "Oil Pressure vs. Oil Flow"

[Rolf Halvorsen]

In general - a simple paper gasket between 2 very small surfaces where you have a a varm oil pressure, are not the best choise of materials. A reinforced steel gasket is in my oppinion the better solution.

[Scud]

5 hours ago, Rolf Halvorsen said:

The 1400 models uses a steel reinforced bottom gasket - to prevent a "blow out" of internal oil - resulting in loss of oil pressure.

This gasket has No: B063861

I will advise this gasket to be used on all big Guzzi's from 1965 and up.

@Rolf Halvorsen have you put one in a V11? It looks like you laid the metal gasket on top of a paper one for the V11 and the holes align perfectly. Would you mind re-posting this advice in the Encyclopedia of Compatible Parts topic?

[Rolf Halvorsen]

Scud 

You can do it for me if you want.

Rolf