rod knock? At 7800 miles?

[Steve W]

As much as I've been trying to convince my self to the contrary, I think my newly acquired '02 LeMans has a rod knock. Not a real bad one, but there's some noise coming from down below at idle that doesn't make me happy. Turn up the rev's a little and all sounds fine. I'm not sure how to diagnose it further without digging in to it. The bike was an ebay purchase, less than 7800 miles on it, and is running great other than the knocking noise. Suffice it to say, I'm pretty depressed about it. But, anyway...

• assuming I need to replace the low end shells, is the procedure written up anywhere? I assume I can just drop the sump and get access to the bottom end - but how much of the internals need to come out?
  
• what's the list of parts I'll need? 2 pairs of shells, rod bolts and nuts, a sump gasket. anything else?
  
• how much are the parts likely to cost me? would MI have all the stuff?
  
• are there any other likely candidates for a noise that sounds like a rod knock? The low milage gives me low confidence in my diagnosis.
  

Thanks for any assistance and sympathy,

Steve

[Guest ratchethack]

Buck up, Steve.

 

The probabilities of you having a rod bearing going South that goes silent above idle RPMs, rather than becoming alarmingly more obnoxious, are slim and ZIP.

 

Wot you're more'n likely hearing is the lovely sound of the valve train singing it's copyrighted Guzzi song.

 

Have you checked the valve clearances? Are they "to the book" US spec (.002" and .004")? If so, "World Spec" is greatly preferable (.004" and .006"). Roper Spec (.005" and .007") or (.006" and .008" -- my choice for many years), or Raceco Spec (.008" and .010") are all generally considered superior alternatives, depending on climate and how ridden, and all will sing the same tune, some more loudly than others.

 

I'd venture you're running one of the "looser" specs, in which case, all's well. But you really should check.

[GuzziMoto]

What rpm do you have it idling at? I don't think Guzzi motors like to idle lower then 1200 rpm. They get noisey below that. I would agree that if it is a rod knock it would probably not go away at slightly higher revs.

What rpm does it knock at and what rpm does it go quiet?

[GuzziMoto]

[*]are there any other likely candidates for a noise that sounds like a rod knock? The low milage gives me low confidence in my diagnosis.

Thanks for any assistance and sympathy,

Steve

Clutch hub splines or other transmission bits are a possibilty. Also a loose timing chain or weak timing chain tensioner spring. But if it's quiet above 1200 - 1400 rpm I would just set the idle there. (Remember the tach may be off by 200 rpm easily).

[Steve W]

Clutch hub splines or other transmission bits are a possibilty. Also a loose timing chain or weak timing chain tensioner spring. But if it's quiet above 1200 - 1400 rpm I would just set the idle there. (Remember the tach may be off by 200 rpm easily).

Well, y'all are making me a little less depressed. I haven't checked the valve clearances yet - it's on the "to do" list. And, I'll check the idle RPM - but if you can't believe the tach, I'm not sure how to accurately report back what it's doing. It doesn't seem exceptionally low - but you don't have to turn the thottle up too much before it goes away.

 

To be honest, here in upstate NY it's still been a bit nippy to get a lot of riding in, so I'm still coming to terms with the bike and haven't made any effort to baseline it yet. But, a cycle-savvy friend was over last night and I was showing it off - and he scowled when he heard the knocking - just as I have been...

 

Thanks for the comments,

Steve

[Guest ratchethack]

. . .a cycle-savvy friend was over last night and I was showing it off - and he scowled when he heard the knocking - just as I have been...

- a typical reaction of the untrained ear to Guzzi music upon first exposure -- particularly when listening in a confined space, and particularly (Part II) when starting up from ambient temp in a frickin' freezin' garage in upstate New York this time o' year.

 

Not to launch a dreaded oil thread, but there are LOTS of oils that could have been used by a PO, very few of which are correct, many of which lack adequate ZDDP that the Guzzi donk needs for adequate tappet protection. Without which, the Guzzi music can be noticably louder than otherwise.

 

FWIW, here's a typical ZDDP additive pitch that explains the nature of the problem:

 

"After 70+ years, the EPA mandated that all domestic oil producers remove ZDDP (Zinc Dialkyldithiophosphate) from all conventional and synthetic motor oil. If your engine was designed before 1989 the non-roller lifters require ZDDP to avoid premature deterioration. ZDDP also alters bearing and journal surface characteristics to prevent metal to metal contact. Under extreme conditions like a high performance motor, ZDDP reduces the tendency of parts to scuff or gall under heavy loads."

 

Interesting letter and follow-on discussion about which here:

 

http://www.ttalk.info/Zddp.htm

[Steve W]

- a typical reaction of the untrained ear to Guzzi music upon first exposure -- particularly when listening in a confined space, and particularly (Part II) when starting up from ambient temp in a frickin' freezin' garage in upstate New York this time o' year.

Yup, that's exactly what I've been doing recently. Maybe that's why when I've actually had the chance to take it out and ride it around for a while, I didn't recall it being particularly noteworthy. frick'in freezin' has sadly been the norm much of the spring so far.

Not to launch a dreaded oil thread, but there are LOTS of oils that could have been used by a PO, very few of which are correct, many of which lack adequate ZDDP that the Guzzi donk needs for adequate tappet protection. Without which, the Guzzi music can be noticably louder than otherwise.

I have a friend who has a commerical account w/ AMSOil and can get it at what appears to be a reasonable price for full synthetic so had him order me a couple gallons of the 20w-50 bike oil. From what I can tell it should address the ZDDP issue. I was either going to use that or try the Mobil1 V-twin stuff.

 

The cold garage has definitely been the impediment to me going through the thing - getting the fluids changed, valves set, TB checked, etc. Also want to fix the ugly block paint which bugs the crap right out of me. So, the rod bearing issue was just one more thing to add to the list. I was just having a hard time accepting it. I'm hoping you're all correct about my mis-diagnosis.

 

Steve

[GuzziMoto]

Sorry, but I think you focused on the wrong aspects of my reply.

I doubt you have ANY serious problem. These bikes WILL make bad sounding noises if you set the idle too low. Yes it will be more noticeable in a cold confined garage.

Stock tachs are usually NOT very accurate on most bikes, not just Guzzis. Yamaha even got into trouble with its R6 a while back over its tach.

Guzzi motors are very reliable mechanically. Don't jump to negative conclusions so fast.

Start with the basics. Ste your idle, check your valve lash, etc. Then enjoy the ride.

[Greg Field]

As others have said, it could be normal engine noises, but I've seen at least three V11 Sports come through the shop that developed rod knocks in under 10,000 miles. It is not that uncommon, sadly.

 

Rig up an oil pressure gauge and test pressure when hot. I have one I could lend you, if you do not want to make your own.

 

Or, just pull the lower and upper sumps, and then remove the rod bolts and inspect the shells. Plan on installing new rod bolts, whatever you find. Also plan on installing a sloppage plate, to prevent this happening again. If you need parts or a plate, they ae available from many sources, among them the shop at which I work, Moto Intl.

[gstallons]

and MI is the best!

[gstallons]

As much as I've been trying to convince my self to the contrary, I think my newly acquired '02 LeMans has a rod knock. Not a real bad one, but there's some noise coming from down below at idle that doesn't make me happy. Turn up the rev's a little and all sounds fine. I'm not sure how to diagnose it further without digging in to it. The bike was an ebay purchase, less than 7800 miles on it, and is running great other than the knocking noise. Suffice it to say, I'm pretty depressed about it. But, anyway...

• assuming I need to replace the low end shells, is the procedure written up anywhere? I assume I can just drop the sump and get access to the bottom end - but how much of the internals need to come out?
  
• what's the list of parts I'll need? 2 pairs of shells, rod bolts and nuts, a sump gasket. anything else?
  
• how much are the parts likely to cost me? would MI have all the stuff?
  
• are there any other likely candidates for a noise that sounds like a rod knock? The low milage gives me low confidence in my diagnosis.
  

Thanks for any assistance and sympathy,

Steve

I'm not ?ing your abilities but do you know what you are doing?

This engine is beautifully simple.Just start removing things that are in the way until you get to the rods.Remove them one at a time marking the position and direction. Make sure the bearing shells are stock and not undersize. when reassembling use Lubriplate white grease. Rotate the engine back and forth a few degrees to be sure there is NO binding or excessive friction on each rod. Use NEW rod bolts and torque EVERTYTHING with NO (dogs barking,wife hollering,friends with beer and other other party supplies)distractions.

If you get unsure, ask? There is no fool like a confident fool.

 

 

p.s. the crankshaft rod journal will get the most damage where you will be able to see it on the bottom of the crank when it is at BTDC.

[Steve W]

Or, just pull the lower and upper sumps, and then remove the rod bolts and inspect the shells. Plan on installing new rod bolts, whatever you find. Also plan on installing a sloppage plate, to prevent this happening again. If you need parts or a plate, they ae available from many sources, among them the shop at which I work, Moto Intl.

Ok Greg, I'll bite - what is a "sloppage plate"?

 

Steve

[Steve W]

I'm not ?ing your abilities but do you know what you are doing?

This engine is beautifully simple.Just start removing things that are in the way until you get to the rods.Remove them one at a time marking the position and direction. Make sure the bearing shells are stock and not undersize. when reassembling use Lubriplate white grease. Rotate the engine back and forth a few degrees to be sure there is NO binding or excessive friction on each rod. Use NEW rod bolts and torque EVERTYTHING with NO (dogs barking,wife hollering,friends with beer and other other party supplies)distractions.

If you get unsure, ask? There is no fool like a confident fool.

Yeah, I'd day I'm far above average in mechanical conpetence for an amateur. Have had probably 40 different old bikes of all makes over the last couple decades, and most of them have been resurrected from dead. Several total rebuilds on old Triumphs, transplanted a short block into my '75 gold wing, etc. But I've never been in the bottom end of a Guzzi and like to have as much info as is available before digging into new experiences. I'm just too old and lazy to try and figure it all out for myself...

 

That's the thing - I've heard rod knocks before, and my '02 sure sounds like it's got a rod knock...

 

Steve

[Greg Field]

A sloppage plate is a device designed for the enrichment of one Pete Roper, an insane Aussie boffin with a midget-porn addiction. It is a faux windage plate that helps keep the oil from sloshing to the back of the sump when you accelerate briskly. Done briskly enough, the oil pickup gets exposed, starving the engine of oil. At very least, keep the engine oil all the way to the full mark. Better yet, keep it to the full mark with the dipstick just being screwed in one turn.

[savagehenry]

what is a "sloppage plate"?

Check the "How to" forum under the pinned heading "Installing a Roper plate", a really well detailed write up by Greg. Basically, it is a "ceiling" that restricts the oil flowing back in the crankcase under hard accelleration, which exposes the oil pick up, located towards the front of the motor. Best, and cheapest insurance you can buy for your motor's oil control. It was thought up and designed by a member here, Pete Roper. You can get them directly from Himself, or Moto Int'l. From your last post, it appears this will be no problem for you to do yourself. I haven't seen my oil light (after start up) since the day I put it in. If you EVER ride in a "spirited manner", you'd be silly not to put one in.