Undiagnosable Front Cylinder noise.
Thread Starter
|
6th Gear
Joined: Jul 2024
Posts: 12
Likes: 1
From: Florida
Undiagnosable Front Cylinder noise.
2001 Night Train Softail TC88B Fuel Injection. 57K Bike developed what appeared to be valve train noise in the Front Cylinder following the installation of Accel Plug mounted coils. To confirm the coils where swapped out with OEM. Noise is still there.
Pulled the cam cover, Tensioners are like new, they where done 15,000 miles ago. There is no debris in the cam chest. An inspection of the lifter showed acceptable wear. The front lifters where replaced. S&S quickees where readjusted. Noise is still there,
Pulled the rocker box cover. An inspection of the rocker arms, showed no unusual wear and the play was well with in specification. The rocker tower did show a minor, and I mean minor mark. Inspected valve springs, valve tips and retainers, no visual issues. Rocker tower, rockers and shafts replaced. S&S quickees where readjusted. Noise is still there.
Compression is good. The exhaust heat shields and exhaust donut is good. Upper Motor mount is tight. The noise is not piston slap or a rod knock. Oil was changed less than 1,000 mile ago with Redline 20W60. I have been using this for a decade with no issue.
The noise does not sound or act like a compensator sprocket. Once I have lift space available I will pull the primary to take a peek. I am not expecting to find anything.
I have had a screwdriver or stethoscope on every square inch of the cam chest, Cylinder, head and rocker box. Everything sound right. Step a foot away from the bike and the noise is there. It is not my imagination. I have had two reputable Harley mechanics do the same. They have the exact same response. The noise is there, but damn I cannot tell you where it is coming from.
The bike runs better than new, but sounds like crap. We are missing something. ANY insight would be appreciated.
Pulled the cam cover, Tensioners are like new, they where done 15,000 miles ago. There is no debris in the cam chest. An inspection of the lifter showed acceptable wear. The front lifters where replaced. S&S quickees where readjusted. Noise is still there,
Pulled the rocker box cover. An inspection of the rocker arms, showed no unusual wear and the play was well with in specification. The rocker tower did show a minor, and I mean minor mark. Inspected valve springs, valve tips and retainers, no visual issues. Rocker tower, rockers and shafts replaced. S&S quickees where readjusted. Noise is still there.
Compression is good. The exhaust heat shields and exhaust donut is good. Upper Motor mount is tight. The noise is not piston slap or a rod knock. Oil was changed less than 1,000 mile ago with Redline 20W60. I have been using this for a decade with no issue.
The noise does not sound or act like a compensator sprocket. Once I have lift space available I will pull the primary to take a peek. I am not expecting to find anything.
I have had a screwdriver or stethoscope on every square inch of the cam chest, Cylinder, head and rocker box. Everything sound right. Step a foot away from the bike and the noise is there. It is not my imagination. I have had two reputable Harley mechanics do the same. They have the exact same response. The noise is there, but damn I cannot tell you where it is coming from.
The bike runs better than new, but sounds like crap. We are missing something. ANY insight would be appreciated.
Seasoned HDF Member
Joined: Dec 2005
Posts: 19,861
Likes: 7,980
From: poway
The best way to tell if it's pistons slap or upper crankpin is to ride the bike. If the sound is based on RPM. it's valvetrain. If the sound is based on load it's Drivetrain.. You don't say what lifters were used..
Is the exhaust system stock? Loose baffle.
Do you hear it going down the road?
Could be a loose comp nut.. Damaged alternator rotor / center cracked..
Is the exhaust system stock? Loose baffle.
Do you hear it going down the road?
Could be a loose comp nut.. Damaged alternator rotor / center cracked..
Thread Starter
|
6th Gear
Joined: Jul 2024
Posts: 12
Likes: 1
From: Florida
The lifters have been replaced. Noise is there hot or cold. Slightly Louder hot. Very hard to tell if it is rpm related, it appears to disappear at speed. The S&S slip on 's can drown out almost anything. Piston slap is possible, but it doesnt sound like it. The HD mechanics and myself have covered every square inch with an ear and screwdriver. Everything sounds correct. Step a foot from the bike. the noise is there. It is absolutely baffling. Bike runs exceptionally well, no vibration, no codes.
Seasoned HDF Member
Joined: Mar 2010
Posts: 38,415
Likes: 6,366
From: Honah Lee
Drive it. Piston slap as long as it's not excessively won't hurt it. You can hear .002 over.
It will kill compression and power as it gets worst. Ever seen much aluminum in the drained oil. Could have a broken piece from the piston skirt.
I would think if it's just from wear, rear would be worst.
Do you use it for a cruiser or bang the rpm a lot?
FI engines last a lot longer then carburetor engines unless you put a tuner on them.
It will kill compression and power as it gets worst. Ever seen much aluminum in the drained oil. Could have a broken piece from the piston skirt.
I would think if it's just from wear, rear would be worst.
Do you use it for a cruiser or bang the rpm a lot?
FI engines last a lot longer then carburetor engines unless you put a tuner on them.
Last edited by Jackie Paper; Aug 14, 2024 at 06:03 PM.
Trending Topics
Thread Starter
|
6th Gear
Joined: Jul 2024
Posts: 12
Likes: 1
From: Florida
Noise existed with original and replacement lifter. Noise existed with the oem rockers, shafts and tower. Exists with aftermarket rockers and new oem shafts and tower. It is not related to the exhaust, the donut and heat shields are perfect and tight.
The compensator sprocket will be checked, when i have an available lift. There is NO noise coming from the primary cover. The shoe was replaced about 5 years ago and recently inspected and adjusted .Charging system is OK,, This was tested recently when I had an issue with the TSSM.
This is a daily rider. One tank Saturday Cruiser, Occasional touring but rarely out of state. I bought this bike 10 years ago with 17,000 miles on it. It now has 57,000. She has been a good a bike. Maintenance is religious. I am not a wacker. I would be a liar if I said I never bounced it off the rev limiter. It is not a daily occurrence . The bike is used for week at time as I rotate with the other bikes in my stable.
I have been tinkering with motorcycles and performance cars for 45+ years . I own an automotive speed shop. The only services I send out is dyno tuning, machine shop services and paint. I haven't been this baffled in many years. Two very qualified HD mechanics are baffled. I know I am missing something.
I am going to dump the oil this weekend. May send a sample out for analysis. I will open the oil filter too. There is nothing in the cam chest.
The compensator sprocket will be checked, when i have an available lift. There is NO noise coming from the primary cover. The shoe was replaced about 5 years ago and recently inspected and adjusted .Charging system is OK,, This was tested recently when I had an issue with the TSSM.
This is a daily rider. One tank Saturday Cruiser, Occasional touring but rarely out of state. I bought this bike 10 years ago with 17,000 miles on it. It now has 57,000. She has been a good a bike. Maintenance is religious. I am not a wacker. I would be a liar if I said I never bounced it off the rev limiter. It is not a daily occurrence . The bike is used for week at time as I rotate with the other bikes in my stable.
I have been tinkering with motorcycles and performance cars for 45+ years . I own an automotive speed shop. The only services I send out is dyno tuning, machine shop services and paint. I haven't been this baffled in many years. Two very qualified HD mechanics are baffled. I know I am missing something.
I am going to dump the oil this weekend. May send a sample out for analysis. I will open the oil filter too. There is nothing in the cam chest.
Last edited by Duckman33426; Aug 14, 2024 at 07:21 PM.
HD Forum Stories
The Best of Harley-Davidson for Lifelong Riders
8 Best Harley-Davidson Motorcycles Ever
Pouria Savadkouei
10 Worst Harley-Davidson Motorcycles Ever
Pouria Savadkouei
Killer Custom's Jail Break Is The Breakout That Refused to Blend In
Verdad Gallardo
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?
Verdad Gallardo
Harley-Davidson Reveals Super Cool Cafe Racer Concept
Verdad Gallardo
Engraved Rebellion: Inside Bundnerbike's Glam Rock II
Verdad Gallardo
10 Motorcycles You Should Never Buy
Joe Kucinski
10 Things Harley-Davidson Needs to Fix in 2026
Verdad Gallardo
Southpaw Super Glide: A Left-Hand-Drive 1979 Harley FXE Built to Fit the Rider
Verdad Gallardo
Thread Starter
|
6th Gear
Joined: Jul 2024
Posts: 12
Likes: 1
From: Florida
I had a few minutes free this morning. Dumped the oil and filter. 3 qts of 20W60 Redline and a K&N Fliter which I had in stock. Noise is reduced slightly, it is till there. Absolutely nothing shiny in the oil. Magnetic drain plug has nothing. I ran a powerful magnet through the oil.nothing. An autopsy of the filter yielded absolutely nothing. Not a spec of metal could be found by the naked eye anywhere. Filter was stained red from the dye in Redline. Everything you would expect from a 1,000 mile oil and filter.