sounds like lower end rod knock but only at idle

[motoloco]

Well it is NOT a rod, everything is nice and smooth above idle, no shavings in oil, been driving it and it runs great. going to re-check the valves tomorrow, maybe they are just sticky from sitting most of its life?

 

[trekker]

While at idle, I hook up my stethoscope and listen. A piece of hose works great. Just be careful around hot/moving parts.

 

[79fj40moneypit]

Did you cut the oil filter open? There may be metal in the folds.

 

[motoloco]

OK it is more like a dieseling sound like pre-ignition ping or knock. it is a 2f with very low orig miles, desmogged with a jacobs ignition and offroad box.

 

[lostmarbles]

OK it is more like a dieseling sound like pre-ignition ping or knock. it is a 2f with very low orig miles, desmogged with a jacobs ignition and offroad box.

Well if that's the case - Mark the distributor position (I use one of those bottles of "white correction fluid" that typists use and that come with the little paint brush) and then try moving it ever so slightly to the left and right (while the engine is running) to see if the noise changes/disappears. (But beware- I'm basically a "40series-diesel-man so my petrol experience comes from other engines to yours -But then I'm sure your ignition timing must be adjusted in this conventional way on your 2F.)

 

[Pin_Head]

The chances of preignition or knock at idle are near zero. Does it get louder with increased engine load, like going up hill with the pedal to the metal? If so, maybe an exhaust leak. Does the knock have the same frequency as the crank shaft or cam shaft? This will help point you in the right direction.

 

[PabloCruise]

How about EGR valve?

I have a leak at mine that sounds like a knock. Very annoying...

 

[motoloco]

it does have an exhaust leak, I will check that EGR.

 

[rsbcruiser]

rsbcruiser, I dont want to sell it, but if I do, and it needs a bottom end, I will tell them it needs a bottom end, cause thats how I roll unlike the guy I bought it from sight unseen

Sorry there, sometimes I think I'm funny when I am indeed not. Most certainly I admire your ethics and would maintain similiar ethics.

 

[rsbcruiser]

Have you tried turning the motor over manually? Remove the plugs and use your handcrank or a 1 3/4" socket on the big nut on the front of the crank. Turn the motor a few rotations to see if it hangs up or makes a sound. Hey, isn't ol Pinhead great at explaining things. I have learned much from his explanations, and Motoloco I do admire your ethics, sorry about the offhand above.

 

[fj40z]

A friend of mine has a 55 that has a knock that looks to be very similiar to what you are describing and it turned out to be his clutch, he thought it was a lifter or rod and then his clutch went out on him this past weekend.

 

[lostmarbles]

Sorry there, sometimes I think I'm funny when I am indeed not. Most certainly I admire your ethics and would maintain similiar ethics.

Oooops. And I wasn't aiming my comments at you either rsbcruiser.

I was just talking about people in general.

My youngest son bought a motorbike from a very well-off kid (judging from the mansion he lived in) only to learn that it had just recently been thrown together. First oil drain revealed lots of metal fragments and closer inspection showed broken castings everywhere.
The family were moving to "the states" and I think the father (who would have put it together) was teaching his son his version of "business ethics".

Luckily motoloco's problems appear to be nothing in comparison to my son's.

 

[srafj40]

Bump:

Need this for quick reference

 

[CruisinMT]

I'm experiencing the same symptoms knock at idle and goes away when engine speed is increased. Did anyone ever figure out what it ended up being?