Ruh Roh Rastro.....

So we picked up Jacquie's GRiSO from the dealer on Saturday. They just completed the "rollerization". The bike seemed to run pretty good, so we were happy to get it back. On the way home, we had a stop in traffic for a few minutes. It was pretty warm and humid (around 90 degrees F). While sitting, Jacquie's oil light came on. The bike was hot, but not that hot. The minute she cracked the throttle even a little bit, the oil warning went off.

We had told the dealer during the service to change the oil pressure sensor as it was coming on randomly even though the bike was running fine, making no noise. The sensor was leaking pretty good too, so we figured while in there to replace.

Now I'm wondering if the when the tappets shat themselves if it didn't take out the oil pump. Has anyone actually experienced that from the tappet failure? I wonder what an oil pump costs? If it has been torched by the tappets, what do you think the odds are that Guzzi will cover it?

Disappointing.

Mark S's bike I chose to replace the oil pump on but it had led a very hard life. Just before my tappets failed and subsequently my big ends I had my oil light come on a couple of times but delivery is still good so I'm going to just slip in some new shells and see what happens. If they fail again I'll be pulling the motor and going through it top to tail. The chances of getting Guzzi to cover it are I'm afraid non existant.

I've discovered that there are substantial differences between the flat and roller cams. I mentioned on the Cheese board that Al has developed a map that works better than Mark's flat tappet map in a Roller GRiSO. It was built specifically for his bike which has an odd pipe combination but until we have the opportunity to re-log and alter the full series of maps for the roller bikes it's currently the best option. I'll flick it over to you.

Pete

Ahh.

Didn't realize that your big ends had gone. I would say the map is the least of my concerns at this point then.

Are you going to turn the crank, or do you think it escaped serious damage?

What do you think the shop time will be for that job?

Can't get undersize bearings but my crank pin is unmarked and it was still running fine, just noisily. With Mark's bike I had the rods closed and ground so the bearings had 2 thou clearance and six thou nip. That seems to have done the trick nicely.

I did a complete engine strip and clean and replaced the oil pump, the only bit left untouched was the idler shaft. All up it cost five grand but most of that was labour.

Pete

I don't think Al's map is a requirement for Jacquie's bike. It's a stock bike after all, and there are many stock roller GRiSO's using the 294C map.

Hokay!

Dealer says he'll pick it up sometime this week. Fingers crossed.

Started it last night just to see if there was any noise coming from the motor at all, and there isn't any. It sounds exactly like it always has (albeit quieter with the rollers). Hoping that maybe it's just the oil pump or better still a faulty sensor.

They're picking it up today, so I should know something by the end of the week.

Got a call from the dealer. They had to get it really hot to duplicate the oil light event. They pulled everything off and put an oil pressure gauge on and found that at idle, it had very little oil pressure, but at 2000 rpm and above, it made 30 or more.

Like me, they could detect no noise coming from the bottom end. They are convinced it is the oil pump. It wouldn't surprise me if it were. I have to imagine there's a good chance the tappet material galled the pump. They've ordered the pump and expect it in next week, so I guess we'll see.

Pete, any idea what normal oil pressure should be? Does their diagnosis make sense to you? I can find nothing that says they flushed the system when they rollerized it. so technically this could be on the dealer no?

Hi WCB, I'm not a motorcycle mechanic but I have fitted a couple of extra gauges to my GRiSO. from the left to right they are,   Engine Oil Pressure,   Oil Temp in deg F,     Exhaust valve cooling oil gallery supply.
This pic displays the engine at Idle immediately after a cold start.
: The Engine oil Pressure is always up around 70 to 80 Psi at this time and will trip the 90 psi alarm I have set if I run it up to 3 or 4 thousand rpm going into town ( I'll have to bump that up to 100 )

: When Hot, oil temp up around 255 deg F, The oil Pressure is around 15 to 20 psi at Idle and still around 72 to 75 psi at 4 thousand rpm cruising.

: Valve cooling Oil pressure ( I found this out from Pete ) is supplied from the sump by a Separate Oil Pump, Via the oil Cooler to each Cylinder head though hoses. No pressure is required for this task as it only needs a flow of oil through the heads to strip the heat away from the exhaust guide area, then it  flows back to the sump. I typically see around 18 to 24 psi on the hwy and down to 5 psi at idle when hot. ( This changes a bit due to outside air temp )

The gauges I chose are Auber 1813's ' Accuracy to + or - 0.2 %
I hope this helped    

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The whole 'Flushing' idea is a pathetic joke. When the tappets go tits, unless you catch it very early like I did, you're going to get a shitload of crud through the engine. At the very least you need to drop the sump as you can't expect just putting a couple of litres of oil in and juggling it about for a few minutes will get all the detritus that will of settled in the bottom of the sump up in suspension and then have it politely line up to run out of the tiny 10mm drain plug! The idea is idiotic! At the very least the sump has to come off for a thorough cleaning and its best to back flush the cooler too along with the coolant lines to the heads. Unless it's making a horrid noise or pressure is poor though it is probably OK to leave the pump but if the tappets have extensive wear you should really go in and look at it.

Also the blokes at your shop do know there are two oil pumps and two circuits don't they? There is the traditional lubrication circuit that will run at about 60-80 lbs pressure when cold as that is the crack pressure of the OPRV but as the oil heats and thins that pressure will drop dramatically at idle to as low as 8-10PSI. As soon as the engine speed increases though it should rapidly increase and by 3,000 RPM, unless it is really stinking hot and oil temp has exceeded 140*C, the pressure should return to close to the OPRV crack point.

The other circuit is the cooling circuit fed by the second pump. This is a low pressure circuit designed to deliver oil in volume but with no major 'Blockages' like hydrodynamic bearings in the circuit the oil just flows. Yes it has an OPRV so if the oil is very cold and viscous it won't over-stress the pump or its drive gear, (which on early engines is plastic.) or the hoses but once warm the pressure on that circuit is very low. This is the one that delivers oil to the heads through hoses.

So, it really depends on where they took their oil pressure readings? If they took them at the oil pressure warning light switch and they were seeing pressure drop to 30PSI at whatever point it stabilised as the revs rose or it only gradually rose to 30psi while they were wringing its neck and the oil was at 100*C+ then it would say to me there is something fucking.

At this point they need to pull the timing chest cover, inspect the pump, drop the sump AND spacer and access the big ends. Drop the caps off the rods and inspect the big end shells, in fact if I were you I'd flip a new set in on principle, they aren't expensive in America, ten bucks a shell or so. Over here they want SIXTY but a shell! I never re-use rod bolts either. I know lots of people do but the risk of calamitous failure is in my book just too high to risk. While the rods are disconnected the crankpin can be inspected. Chances are it will be fine, it's the bearing shells that are sacrificial.

IF though there is strong evidence of particulate damage to the shells, (Score marks or a mottled look from embedded material.) or, heaven forbid, there is scoring of the crank then at that point there is really no option but to do as we did with Mark Salkeld's bike. Engine out and down to the last nut and bolt to inspect everything, linnish the crank, re-size the rods and render it absolutely 100% squeaky clean and crud free before reassembly. The crank design has changed and no longer has a sludge trap per se but has through drilling so with plugs in the end. If the crank is out these should be removed and the galleries in the crank thoroughly cleaned of detritus as well.

I've cut a few corners on my bike when it came to doing the bottom end but as I said its MY bike. If it shits itself then the only person to suffer will be me. If it wasn't mine I would have the motor strewn from arsehole to breakfast just like Mark's. Thing is if they have ANY doubts? Get it done RIGHT sure it'll be expensive but it'll be a damn sight cheaper than addressing the issues one at a time as they take out other components and inflict more damage though serial failures.

I was going to say Ron has gauges on his bike and should be able to give accurate 'Healthy Engine' figures but he's beaten me to the punch.

Pete

Thanks all. They're pulling the main pump first. From what I understand, the oil pressure light came on when it was very hot, and they found that even cracking the throttle turned it off. My initial feeling is that the conrod bearings are fucked, but they're optimistic that it's the pump as they had a Norge behave the same way with a bad pump.

My Ambo had had the chrome flake and go pretty much all through the motor on that, and the pump was fine so I find it hard to believe a small amount of tappet swarf 86'ed the pump. We'll see I guess.

I think I'll probably have them pull the caps and check the bearings and crank at this point anyway, as I'm not sure I'd ever feel comfortable with it if I didn't. Unless of course they pull the pump and it's mangled.

Thanks again for the info gents.

Thing is Doug if the pump is bad and pressure is low the result is fucked big ends.

Pete

I agree. I'm gonna do them too before any more damage happens.

WCB wrote:

Thanks all. They're pulling the main pump first. From what I understand, the oil pressure light came on when it was very hot, and they found that even cracking the throttle turned it off. My initial feeling is that the conrod bearings are fucked, but they're optimistic that it's the pump as they had a Norge behave the same way with a bad pump.

Was that an 8V Norge or a 4V? There was a run of bad oil pumps on the early 4V Norges.

The 8V pumps are in the same location in the bottom of the timing chest but are both in one housing. To remove it you have to drop the sump and remove the cooling circuit pick up and also the oil cooler so you can get the fitting out of the side of the block that the cooling oil delivery pipe goes through. Then you can undo the three mounting bolts and wriggle the pump housing off the block. It can then be taken apart and inspected. Mark's had some minor scoring and I was tossing up whether to re-use it but since his big ends were shot and I didn't know why AND the fact that it had led a terribly hard life prior to his acquiring it I thought discretion was the better part and replaced it. The early Norges used to shatter the outer pump rotor. No such similar damage on Mark's pump and neither have I heard of a pump failing in this way. It will be interesting to see what they find.

From the point where you have the sump off to access the cooling oil pick-up it is only four more bolts to drop the sump spacer to access the big ends. If the bottom end is silent it's probably fine though. Find out where they took the oil pressure readings and at what engine speed? Both Mark and my bikes made a horrible noise when the big ends let go. With Mark's it really sounded like a top end knock. With mine though it swiftly became apparent it was a big end knock! It sounded like an 0-4-0 shunting loco moving coal wagons in a freight yard!

Pete

I'm pretty sure they pulled the oil pressure sensor and put the oil pressure gauge there.

I'm not sure if the Norge they referred to was an 8v or 4v.

Pete Roper wrote:

The whole 'Flushing' idea is a pathetic joke. When the tappets go tits, unless you catch it very early like I did, you're going to get a shitload of crud through the engine. At the very least you need to drop the sump as you can't expect just putting a couple of litres of oil in and juggling it about for a few minutes will get all the detritus that will of settled in the bottom of the sump up in suspension and then have it politely line up to run out of the tiny 10mm drain plug! The idea is idiotic! At the very least the sump has to come off for a thorough cleaning and its best to back flush the cooler too along with the coolant lines to the heads. Unless it's making a horrid noise or pressure is poor though it is probably OK to leave the pump but if the tappets have extensive wear you should really go in and look at it.

Also the blokes at your shop do know there are two oil pumps and two circuits don't they? There is the traditional lubrication circuit that will run at about 60-80 lbs pressure when cold as that is the crack pressure of the OPRV but as the oil heats and thins that pressure will drop dramatically at idle to as low as 8-10PSI. As soon as the engine speed increases though it should rapidly increase and by 3,000 RPM, unless it is really stinking hot and oil temp has exceeded 140*C, the pressure should return to close to the OPRV crack point.

The other circuit is the cooling circuit fed by the second pump. This is a low pressure circuit designed to deliver oil in volume but with no major 'Blockages' like hydrodynamic bearings in the circuit the oil just flows. Yes it has an OPRV so if the oil is very cold and viscous it won't over-stress the pump or its drive gear, (which on early engines is plastic.) or the hoses but once warm the pressure on that circuit is very low. This is the one that delivers oil to the heads through hoses.

So, it really depends on where they took their oil pressure readings? If they took them at the oil pressure warning light switch and they were seeing pressure drop to 30PSI at whatever point it stabilised as the revs rose or it only gradually rose to 30psi while they were wringing its neck and the oil was at 100*C+ then it would say to me there is something fucking.

At this point they need to pull the timing chest cover, inspect the pump, drop the sump AND spacer and access the big ends. Drop the caps off the rods and inspect the big end shells, in fact if I were you I'd flip a new set in on principle, they aren't expensive in America, ten bucks a shell or so. Over here they want SIXTY but a shell! I never re-use rod bolts either. I know lots of people do but the risk of calamitous failure is in my book just too high to risk. While the rods are disconnected the crankpin can be inspected. Chances are it will be fine, it's the bearing shells that are sacrificial.

IF though there is strong evidence of particulate damage to the shells, (Score marks or a mottled look from embedded material.) or, heaven forbid, there is scoring of the crank then at that point there is really no option but to do as we did with Mark Salkeld's bike. Engine out and down to the last nut and bolt to inspect everything, linnish the crank, re-size the rods and render it absolutely 100% squeaky clean and crud free before reassembly. The crank design has changed and no longer has a sludge trap per se but has through drilling so with plugs in the end. If the crank is out these should be removed and the galleries in the crank thoroughly cleaned of detritus as well.

I've cut a few corners on my bike when it came to doing the bottom end but as I said its MY bike. If it shits itself then the only person to suffer will be me. If it wasn't mine I would have the motor strewn from arsehole to breakfast just like Mark's. Thing is if they have ANY doubts? Get it done RIGHT sure it'll be expensive but it'll be a damn sight cheaper than addressing the issues one at a time as they take out other components and inflict more damage though serial failures.

I was going to say Ron has gauges on his bike and should be able to give accurate 'Healthy Engine' figures but he's beaten me to the punch.

Pete

So the saga continues. They pulled Jacquie's GRiSO apart and checked the oil pump and it had some very minor scoring. Nothing worth talking about. They replaced it anyway as they had one on hand. Then they found that there was a broken piece of gasket inside the sump. They took the the second sump plate down and found that the gasket was broken there. They hypothesized that the broken section of gasket was allowing the pressure not to build correctly. They cleaned and replaced all the gaskets, put everything back together and started it up. They found cold, the oil pressure at the oil pressure switch location was around 60 psi. They warmed the engine up to about 100c (200f) and found that at idle at that temperature was about 17 psi. Once the throttle is cracked it would climb right up to around 50 psi. The oil pressure warning light does not come on at idle when the bike is hot like before.

So what's the verdict? 17 psi at idle seems low to me, but I appreciate the oil may be fairly thin at that temp. What say you'se? As an aside, there is absolutely no bottom end noise at all coming out of the motor.

As I have never had the sump down on Jacquie's bike, and since it appears that the bike was assembled with a damaged gasket, any chance Guzzi will cover the cost of this? I suspect the answer will be no.

Thanks all.

Doug

You can ask, and it's not the first case of this problem I've heard of, but I don't reckon they'll come at it.

As for 17PSI at idle, hot, that's about what I'd expect and between 50 and 60 hot is about what Guzzis have always popped their OPRV's at.

Pete

Awesome. Thanks Pete. Then I guess we got lucky. She's excited to pick it back up. She's been without it for a while now and she gets anxious without it. :}

I find it hilarious when a well educated Doug armed with Pete's input, is going to the dealer to tell them how to fix the bike (more or less). lol
Hopefully, it's all sorted now...

Glad you got it sorted Doug, i had to have a new pump, crank and cases!

WCB wrote:

Awesome. Thanks Pete. Then I guess we got lucky. She's excited to pick it back up. She's been without it for a while now and she gets anxious without it. :}

Digging Jacquie's GRiSO vibe...