knocking? 6.5td

[vsandme]

I have a 1994 6.5 td thats been making a strange knock....could this be injector or lifter? Noise is coming from intake nearly. Here is a youtube video. https://m.youtube.com/watch?v=xnusrtII_zk

[Robyn]

The noise is coming from the air intake and is likely a lifter that has collapsed allowing an intake valve to remain open a tad too long.

This is a common noise when a lifter either bleeds down or if there is a lifter failure and or a cam lobe failure.

Did this just start suddenly ???

A compression test may give some insight.

You can loosen injector lines at the injectors one at a time and see if you can locate the offending cylinder (valves)

Start with the drivers side injectors as they are the easy ones.

Whats the oil pressure like???


Robyn

[vsandme]

Fairly sudden. I replaced plastic cap that was broken on a driverside lifter and that didnt solve it.... im gueasing i will have to disect the annoyimg passenger side

[DmaxMaverick]

Do an injector test first. Loosen the injector line nuts, one at a time while the engine is idling (and knocking). Once the suspect cylinder is identified, swap that injector with another cylinder and repeat the test. If the noise follows the injector then that injector is the problem. If the noise remains at the original cylinder, then the problem is with that cylinder.

[vsandme]

Ive already cracked every injector 1 at a time the noise remains with each one

[Robyn]

my bet is a bad lifter or a failed cam lobe.

The noise is the same common sound if there has been a lifter bleed down.

The noise will go away as soon as the oil pressure comes up.

Get the Pass side V cover off and look over the valve train carefully.

Check for a rocker that has excessive lash.

Changing lifters is doable, but takes some finesse to get the hold down plates and guides out.

With the head off it's a snap, but that makes far more work.

[Big Green]

Also try test starting with the belt removed. Sometimes the source of a noise can be hard to pin down.

Also check the harmonic balancer and the crank pulley.

My crank pulley failed recently and it sounded awful. Friend of mine wanted to know if it had a broken crankshaft.

Big Green