Piston slap at 30,000 miles?

[dolt]

Brought the bike home today after talking with tech at dealer who said it sounded like slight piston slap but did no tests( leak down or compression)so I am just gonna ride until she blows or I figure it out because I do not think it anything serious probably just something minor I am missing, these bikes are noisy plain and simple. Thanks for all the help.

That's a plan, not one I would subsribe to but at least a plan. My bet is that you will tire of the noise. At least send an oil sample to Blackstone to see if the level of aluminum in the oil is high, or any other anomolies are detected. If high levels of aluminum are detected, probably a good idea to pull top end, bore and fit new pistons. If there is a high level of aluminum in the oil it is just a matter of time before some bad juju happens.

You can replace lifters and pushrods at the same time. I hope you find a more simple solution but an oil sample/test is cheap and will tell you a lot. You can also purchase a compression tester (Sears has a good one) for $25-$45 and check compression your self. It will probably cost less to by a compression and leak down testers than it would cost to pay a tech to make the test. If you test, at least, you would know that the test were performed correctly and the results accurate. Good luck!

 

[markfsanderson]

Sorry about the silly question . . . But what IS piston slap? From my mind's eye I can imagine a piston impacting a wayward valve . . . but wouldn't that be a catastrophic failure that cause the engine to immediately stop?
After I had a flood in my house some 3 years ago which also killed my car, I purchased a 1997 Honda Accord (still have it) . . . great car - but I was told that absent any service records IMMEDIATELY replace the timing chain. If the timing chain breaks in these Series 5 Accord engines - both the valve train and pistons will spin free, impact and cause sudden catastrophic failure. Just curious . . .

Mark - Thanks!:newsmile026:

 

[Hoople]

what IS piston slap?

It's the noise created when a "loose fitting" piston rocks within the cylinder bore during the time it changes direction.

 

[markfsanderson]

It's the noise created when a "loose fitting" piston rocks within the cylinder bore during the time it changes direction.

Hmm, this does sound like eventually the engine will fail as it just shakes itself apart . . . not fun.

Mark - Thanks!:newsmile026:

 

[Hoople]

My opinion,,, it's not piston slap. I bet it's a cam bearing, cam tensioner, lifter, or oil pump related.

It gets worse when hot. Stopping and restarting engine got rid of it for a little while. That to me is not piston slap.

 

[BUBBIE]

Hmm, this does sound like eventually the engine will fail as it just shakes itself apart . . . not fun.

Mark - Thanks!:newsmile026:

********************************************

ON my old BSA 441 Victor (?1965?) bike, (a cross country type and for the road)...
They were set up with "A" LOOSE fitting piston.. Reason, Running thru a river, stream or a Big mud puddle, Fully coverd and INSTANTLY cylinder COOLED, would cause the Piston to FREEZE up in the cylinder as they didn't cool as fast as the cylinder did. So MORE room (loosed fitting piston)
was needed.

Piston slap TO ME is WAY over rated as a Problem that ear-plug wouldn't remady before spending a lot of :53::53::53::53: on.

Well,,,, maybe ON some one ELSES bike:newsmile100:

signed....BUBBIE

 

[Jack Klarich]

My opinion,,, it's not piston slap. I bet it's a cam bearing, cam tensioner, lifter, or oil pump related.

It gets worse when hot. Stopping and restarting engine got rid of it for a little while. That to me is not piston slap.

Piston slap will surely get louder as parts expand and RPM goes up, do a compression test, then pull the heads if low readings are found. Rocking the pistons will be a tell tale sign of slap, If you pull the barrels off you will SEE the wear marks

 

[kyhdman]

i had a knock a few yrs ago as it got wamer it got louder not real bad but annoying pulled the primary cover and checked compensator nut and DITTO no knock since

 

[Jack Klarich]

A cracked piston skirt will also make this noise, typically you will have more than normal oil consumption here also

 

[HDSickness]

Well the noise is bugging me to no end so I took her to the local indy shop and he had a good listen and said rear cylinder slap. I guess this would be a good time to do a 95" kit. Hope this cures everything. Guess we will see.