Warranty Issue

My oil light came on so I took it to my dealer where they determined the oil pump was to blame and it would be replaced under warranty.i went back to see how the work was going and they said Moto Guzzi had denied the warranty claim and given them no reason.They refuse to order the part or perform the work until MG gives them the go ahead.Do I have to fight with MG or should my Dealer perform the work and fight it out with MG on their own time.This is fast becoming a legal problem,who should be on the hook here MG or my Dealer?The bike has 4300kms on it and was purchased from the dealer in January.The oil has never run low since I have owned it.Bought with 1400kms on the clock and first service done at the dealers.I want my GRiSO back..sob,sob.Stan.

When you say the oil light came on and you took it to the dealer, did you ride to the dealer or trailer it? I ask this because it will give some indication of the competence of the dealer.

Pete

I rode it to the dealer.The light would only come on after 25 to 30 minutes of riding and only at idle.The day I rode it to the dealer the light did not come on as it is only 2kms away.As for the competency of the Dealer I have yet to meet anyone with anything good to say about them and I have been riding motorbikes in this town with a lot of people since 1986. Regards,Stan.

Stan, it is very, very unlikely to be the oil pump.

You have to understand a couple of things about what the oil actually does and how.

Oil is not in the engine "To make things slippery." Nor is its quantity of terrific importance as long as there is *Enough* for it to cover the pick ups in the sump, at least in the short term.

The way it works in the plain bearings that the crank and connecting rods run in and the cam bearings in the camboxes is that oil is supplied under pressure and as the journals spin in the bearings they form what is called a 'Hydro-dynamic wedge' that prevents the journal and the bearing touching, a condition known as 'Boundary Lubrication'. Without a constant supply of oil, at pressure, this wedge cannot form and if the wedge cannot form then boundary lubrication begins to occur immediately and damage will be almost instantaneous and catastrophic.

Think about it for a moment. The circumference of a circle is calculated as Pi x D with D being the diameter of the circle. Say the rear main bearing journal is 50mm across? Pi is 3.142 but to keep it all simple lets round it down to 3 for this example. So the rear main bearing has a circumference of 150mm. Every time the crank spins the journal and bearing move 150mm in relation to one another.

If the engine is spinning at 5,000 rpm then every minute the two surfaces move over each other at a rate of 750,000 mm per minute or 750 metres per minute or 12.5 metres per second.

Now imagine being towed down the road on your arse behind a car at 12.5 metres per second. How long do you think your arse would last?!

Well, it's the same with bearings. Unless you are very lucky and very observant by the time you notice the oil light it's generally all over, red rover!

The oil light switch operates, (If it's working correctly.) at about three PSI. If it comes on and you've ridden for more than thirty seconds and the engine hasn't made the dreaded 'Dogga-Dogga' noise of death it is extremely unlikely that the oil pump is the culprit.

My guess is that it is a dodgy oil pressure sender switch. These are notoriously prone to screwing up. Oddly some never go wrong. Others fail early in the piece. Quite simply it's a shitty part and a lottery.

My advice would be before letting these people you don't trust start ripping into your motor you buy a new oil pressure switch and mount it. The part has been changed and the new one also requires a new mounting fitting but they aren't expensive and I can see all sorts of opportunities for you to be left bikeless or with further damage if someone who doesn't understand the basics of lubrication is let loose in your timing chest to change the oil pump!

If you want to do it yourself it's not difficult. Hardest part is removing the tank! If the shop is being unhelpful I'll send you a switch and mount and if it cures it you can pay me for 'em. This whole thing is so fuquetardian it beggars belief!

Pete

Thanks for the input Peter.When they first diagnosed the bike and said it was the oil pump I told them that I had heard that the sensor was a notoriously dodgy part and perhaps they should check that first.They condescendingly replied that if I would sign off on that they would replace it,implying that I would be an idiot to do so.I am going to the shop when they open on Tuesday to suggest they replace the sensor which they probably won't have in stock.I have heard that VW or BMW have a sensor that works for this application that I might be able to acquire immediately.If not I may take you up on your kind offer.Regards,Stan.Hey Peter,upon second thought I will take advantage of your offer to send me the sensor my details are Stan Hicks 1322 johnson st.Victoria British Columbia V8V3P1 That's in Canada,eh.Thanks so much,Stan.

No worries, I'll dig one out today, and the fitting.

Pete

Stan, new type switch and fitting on way. Note you will need a sealing washer for between the switch and the mount and one for between the mount and the block. An alloy washer is fine for both. You'll also need to snip off the plastic fitting on the pressure switch wire and install a spade connector.

Pete

Good one Pete.
Unless the drive key ( woodruf ? ) was omitted at the factory, these pumps should last forever.
How hard would it be to screw a fitting in somewhere to hook up a temporary test gauge to test the actual oil pressure. I took mine from a hand made adapter under said pressure switch, is there a threaded plug more accessible for testing purposes ?

Pete Roper wrote:

Stan, new type switch and fitting on way.

And people wonder why some would stay in the Ghetto! Nice one Pete.

waterbottle wrote:

Good one Pete.
Unless the drive key ( woodruf ? ) was omitted at the factory, these pumps should last forever.
How hard would it be to screw a fitting in somewhere to hook up a temporary test gauge to test the actual oil pressure. I took mine from a hand made adapter under said pressure switch, is there a threaded plug more accessible for testing purposes ?  

The pump is driven by a pin that goes through the shaft and engages in two detentes in the gear.

No real 'Other Place' to fit a guage unfortunately.

If it isn't the sender then the next place to look would be the OPRV. Only if that turned out to be good would I think about diving into the timing chest.

Pete

Hey Peter,went to the shop today to convince them it could be the sensor.They had put a new guzzi tech on the job who hasn't looked at it yet but he immediately said he knew it wasn't the pump.I talked to him for a while and he seemed very knowledgeable but so would a turnip compared to the service manager.Told him the sensor was on it's way but he was still worried about the previous techs report which had measured the oil pressure at 5psi at cold idle.Feeling much more upbeat after talking to Trent the new tech,Hopefully he can sort things out.Thanks for your help,Regards,Stan.

Where did he measure the oil pressure? If he did so at somewhere easy like a cooler fitting or a line to the head he would of been measuring the low pressure, cooling circuit. I have no idea what it runs but not a lot, it doesn't have to. Do these people know the engine has two oil pumps delivering to two different circuits that perform completely separate functions?

Pete

I hope the new tech knows this,I knew it but maybe the original guy working on the problem did not.Regards Stan.

From a cold start At idle, from left to right,
engine oil pressure, 75 psi
oil temperature in degrees F, 68
cylinder head cooling oil feed pressure ( from oil cooler )11 psi , this can go down to 4 or 5 psi at idle hot


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Yarp. That's what I guessed it might be. Looks like old donkey-breath decided to take a reading on the cooling circuit. What is the word that rhymes with 'Duck'?

Pete

Speaking of the oil pressure sending unit, I had mine replaced last season at just under 10,000k on the 2012 model.

Pete, when you say "new" type switch, can you tell me when MG started using them and getting them into dealer hands? I am wondering if the replacement opss installed on my bike is the new type. Are there any design differences that would distinguish the new from old part? Would you know or agree that the new part is an improvement over the old?

I hope this is what they did at the shop.The new tech will take the oil pressure at the proper place I hope.Stay tuned,Regards,Stan.

1151 wrote:

Speaking of the oil pressure sending unit, I had mine replaced last season at just under 10,000k on the 2012 model.

Pete, when you say "new" type switch, can you tell me when MG started using them and getting them into dealer hands? I am wondering if the replacement opss installed on my bike is the new type. Are there any design differences that would distinguish the new from old part? Would you know or agree that the new part is an improvement over the old?

No, it's nothing special or wonderful and I'd guess it all comes down to price. The original switches used on the 8V use a connector similar to the injector plugs but with a single pin. This is a much more elegant but also probably expensive solution than the 'Old' system which has been re-adopted. The 'New ' switch simply has a spade connector on top. Why it needs the adaptor mount I don't know? Presumably a different supplier and it was easier/cheaper to make the mount than get them to change the thread form on the already available. 'Off the Shelf' switch.

The switch itself will be the same crappy little diaphragm with a contact in the middle that when the pressure elevates above zero-ish will unseat and make or break a circuit.

Pete

Gotcha.....thanks for the information Pete!

Hi Peter,got a message from the mechanic on Friday saying he would put the bike back together and swap out the oil pressure sensor when it arrived.Went to get the bike on Tuesday,they are now taking off the bottom as they believe it is the pressure relief valve.They also say Guzzi is refusing to cover any of this under warranty.He talked about 5psi so I think he means for the cooling oil feed.Not feeling very good right now.Hope it turns out OK.Regards ,Stan.

The cooling feed and the lubrication feed are completely different. The relief valve for the cooling feed is adjacent to the pump in the timing chest. The lubrication relief valve is attatched to the sump spacer.

Jeez I hope these blokes know what they're doing. Reading the fucking manual would help methinks.....

Pete

well Pete, I'm shure they didn't but if they did, the manual has errors too, like the thermostat that isn't there.

Yeah, I suppose you're right.

Anyway I've got my own issues. I've got to find out why Mark S's bike makes such a horrible knocking sound. I don't think its the top end which has just been rollerised. I fear it may be deeper down. Bleargh!

Pete

Hello Peter,went in today and got the bike back,the new tech,Trent who they had put on the bike had determined with help online that the gasket had failed and the oil was going back into the sump area and the pressure was dropping drastically.He had taken apart the oil filter then checked all the screens and couldn't find a trace of metal.He looked at the problem on his own time and explained to me everything he had tried to find the problem.Many of my friends hate or are barred from this dealer but I have to give kudos to Trent for his work.Oh by the way I have yet to receive the oil pressure sensor but when I do I will keep it and just send you the money so I have it in stock,if that is OK with you.Regards,Stan.

Look, it looks like he's trying and that's really good. If he wants to please get him to email me and I'll happily cosult. This is not hubris, I simply have as much experience as anybody else on the 8V and really want to help if I can.

Pete