Guzzi-in-Vancouver Posted June 24, 2023 Posted June 24, 2023 So today I experienced a loss of engine power, unusual shaking and vibrations, and the engine oil light came on. Then the bike lost power, the engine cut out and then had difficulty starting. I barely made it home on severely reduced power. Some history: A few months ago I had a false alarm when the oil light came on after a hard stop. But it also came on intermittently on a short ride a few days ago. The oil & all fluids were recently changed, then, a few weeks later, one cylinder wasn't firing and the spark plugs were black with soot, and were replaced by the mechanic who gave it a good 20 minute shakedown to ensure things were running well. Other than that it runs well, the gearbox is smooth etc. (today I was practicing clutch-less upshifts and the gearbox never gave any trouble). There's no oil leakage at all, no spots on the garage floor where I park it. The oil spots in the video are from checking the oil with the dipstick, and it does look very dirty considering it was replaced this spring. What could these problems be caused by? I fear that I've broken something inside the engine. The engine slows down and the handlebar shake can be seen near the end of the video, and then it just cuts out. I had to limp home on very little power and low revs.
Lucky Phil Posted June 24, 2023 Posted June 24, 2023 It's running on one cylinder hence the rough running and noise. Phil 3 1
audiomick Posted June 24, 2023 Posted June 24, 2023 Assuming Phil is right (which I don't doubt), carefully !! check the headers after letting it run for a minute. The cold one is the cylinder that is not firing. If both cylinders are firing, the headers will be equally warm.
pete roper Posted June 24, 2023 Posted June 24, 2023 Is it making a knocking/clanking noise from the engine when you open the throttle? If so I'm guessing you've run the big ends, especially given the 'Dirty oil' situation. Are you running a sloppage sheet? 2
Guzzi-in-Vancouver Posted June 24, 2023 Author Posted June 24, 2023 4 hours ago, pete roper said: Is it making a knocking/clanking noise from the engine when you open the throttle? If so I'm guessing you've run the big ends, especially given the 'Dirty oil' situation. Are you running a sloppage sheet? @pete roper that's what I was afraid of, and yes, the noise/vibration is worse with an open throttle, like a LUNK LUNK sound. I am running your sloppage plate. The oil light has come on intermittently for the last two rides. The oil was changed a few months ago too. I wonder what the cause was, did the oil pump give out, or something else that caused the oil pressure light to come on intermittently? I suppose this problem is not fixable and that the engine is done for? @Lucky Phil & @audiomick both cylinders are firing, I checked the exhaust is fine on both. So unfortunately we have a big end problem... I will see if I can get a better video, but it's probably best not to run the engine any more... 2
audiomick Posted June 24, 2023 Posted June 24, 2023 50 minutes ago, Guzzi-in-Vancouver said: but it's probably best not to run the engine any more... Yes. If you have chewed a big end, the oil is most likely full of metal. I did a big end on a V35 a year or so ago. The oil was full of fine, silvery metal dust. Drop it out and have a look.
andy york Posted June 24, 2023 Posted June 24, 2023 Kinda looks like the left throttle body may have burped itself off the intake rubber. just trying the simple things first. 9 1
Lucky Phil Posted June 24, 2023 Posted June 24, 2023 4 hours ago, andy york said: Kinda looks like the left throttle body may have burped itself off the intake rubber. just trying the simple things first. Well spotted. Phil 4
footgoose Posted June 24, 2023 Posted June 24, 2023 4 hours ago, andy york said: Kinda looks like the left throttle body may have burped itself off the intake rubber. just trying the simple things first. and check the rubbers for dry rot cracks. the right one is suspect. get the left one reinstalled and do the "spray to reveal leaks" test on both 4
Guzzi-in-Vancouver Posted June 25, 2023 Author Posted June 25, 2023 15 hours ago, gstallons said: Well G-I-V , what did you find out ? It will be going in for service next week. Thank you for the suggestions everyone. @andy york I checked under the boot, there's some leaking fuel there though this is not conclusive (per docc's post on not pressurizing the fuel system & this one). @footgoose I will try that, thanks for the suggestion. @audiomick will also get the pan dropped, it wasn't dropped on the last oil change. With fresh fluids and a test ride that didn't indicate anything wrong, the mechanic seems to think it isn't the big end, so I'm hoping against hope that this is not a big-end problem, though that intermittent oil light gives me nightmares. Currently searching the forum for oil lamp and oil pump issues. 2
docc Posted June 25, 2023 Posted June 25, 2023 On 6/24/2023 at 1:37 PM, andy york said: Kinda looks like the left throttle body may have burped itself off the intake rubber. just trying the simple things first. 2 hours ago, Guzzi-in-Vancouver said: It will be going in for service next week. Thank you for the suggestions everyone. @andy york I checked under the boot, there's some leaking fuel there though this is not conclusive (per docc's post on not pressurizing the fuel system & this one). @footgoose I will try that, thanks for the suggestion. @audiomick will also get the pan dropped, it wasn't dropped on the last oil change. With fresh fluids and a test ride that didn't indicate anything wrong, the mechanic seems to think it isn't the big end, so I'm hoping against hope that this is not a big-end problem, though that intermittent oil light gives me nightmares. Currently searching the forum for oil lamp and oil pump issues. Man, I would so re-seat that left throttle body into the intake rubber and restart, if even briefly. The very low idle from the dislodged throttle body could be all there is to the oil light. My recent Horrible Noise Story: At the Kentucky SpineRaid, I had (somehow) mis-set my new TPS (like nine steps off on the map, 95 mV instead of 157). At idle the beating, banging mechanical noise was deftly disturbing. At start-up to head home, @kalev11's eyes got wide. He said some thing like, "I hope you actually get back home." Turns out, with the TPS indexed that far off, the battering of the motor trying to run was alarming. While this case is not the same, a throttle body off its runner could be the culprit . . . 6 1
pete roper Posted June 25, 2023 Posted June 25, 2023 4 hours ago, Guzzi-in-Vancouver said: It will be going in for service next week. Thank you for the suggestions everyone. @andy york I checked under the boot, there's some leaking fuel there though this is not conclusive (per docc's post on not pressurizing the fuel system & this one). @footgoose I will try that, thanks for the suggestion. @audiomick will also get the pan dropped, it wasn't dropped on the last oil change. With fresh fluids and a test ride that didn't indicate anything wrong, the mechanic seems to think it isn't the big end, so I'm hoping against hope that this is not a big-end problem, though that intermittent oil light gives me nightmares. Currently searching the forum for oil lamp and oil pump issues. It's very, very unlikely to be oil pump. Possibly a loose filter or the old filter gasket wasn't removed when the filter was last changed. 4
gstallons Posted June 25, 2023 Posted June 25, 2023 I have seen less than four oil pump problems im 50 yrs of tinkering w/things. Historically , oil filters n o-rings are at the top of the list . 1 1
pete roper Posted June 26, 2023 Posted June 26, 2023 Quite. Unless they ingest some horrible shite why would they wear out? They're probably the best lubricated thing in a motor! 1 1 2
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