My Fluidamper saga.

[EDankievitch]

As I recall on the Volvo D4 and D6 you have to index the Cp3 pump gear to the cam and engine. The reason was to quiet the gear noise. The Cp3 will work in any position but if not indexed there would be for lack of a better term gear slap. Maybe your engine is doing the same and is more noticable with the FD??? Just a thought.

 

[cerberusiam]

No one is saying the CP-3 is making the noise.

 

[sag2]

The CP3 isn't making the noise they are referring to, the gear train is from the pumping pulses out of the three cylinders as they load and unload the gear train. If you listen to the attached recording you can hear the metallic knock/click in the first half, then it goes away after the CP3 is re-timed by 30 degrees.

Sorry, can't attach a . wav file. If someone knows how it is a great file and the difference in sound by timing the pump is significant.

 

[Prairie Dog]

Sag, did you listen to the video I posted? Is that the sound you hear? link The noise starts at about 24 seconds.
I'd sure like to hear the sound clip you have. . Sag, I sent you an email. If you can send me the file, I'll try and attach it to a Utube video.

 

[Prairie Dog]

Here is the sound file Sag2 provided. I had to turn it up loud to really hear the difference. Note that the second half is after the CP3 is retimed 30degrees.
Pre/post CP3 retime

Unfortunately this isnt exactly what I hear. This sound is much more rhythmic.

 

[cerberusiam]

Unfortunately this isnt exactly what I hear. This sound is much more rhythmic.

I can hear the gear slap in both of your videos, the same as sag2's. It is more pronounced in the FD video with the addition of a new noise.

 

[TCDiesel]

The eccentric shaft (CP3) is free in 1 position until it is under load. . Under load the geometry is equal. There is No load or unloading,once fuel enter the HP side the holes are always under pressure. Can someone point Me to the devise that regulates the Pressure on any CP3? its NOT the FCA,the FCA controls Volume. The noise I hear is completely related to combustion.

 

[Prairie Dog]

Todd, assuming it's combustion related, why would the noise be sporadic? It's just a jumble of misc snaps and clicks rather than a tick-tick-tick-tick. .
FWIW, I was concerned about timing so I checked it with my SmJr set to stock and #3 and there was no difference.
Personally I find it interesting that in my video it takes the eng about 20+ seconds to start making the noise.

 

[cerberusiam]

There is No load or unloading,once fuel enter the HP side the holes are always under pressure.

Taking fuel from 75 psi to 6-23k psi is a pretty clear definition of load.

The intake stroke for the next fuel pressure cycle is pretty definite unloading.

The CP-3 drive shaft is subject to rotational spikes just like the crank shaft.





The FCA controls pressure by the amount of fuel that is allowed to enter the high pressure circuit as commanded by the ECU via the rail pressure sensor. But you know all that and it is moot to the discussion at hand.

 

[TCDiesel]

Todd, assuming it's combustion related, why would the noise be sporadic? It's just a jumble of misc snaps and clicks rather than a tick-tick-tick-tick. .

FWIW, I was concerned about timing so I checked it with my SmJr set to stock and #3 and there was no difference.

Personally I find it interesting that in my video it takes the eng about 20+ seconds to start making the noise.

If you had the correct tools you could replicate the Noise... There is So much misunderstanding how Positive displacement pumps function. . I just don't have the time to type corrections (Don't won't too neither) PD you know my #s so feel free to call. In the end the noise will be attributed to combustion. The FD is getting a bad rap in this deal.

 

[Prairie Dog]

I think I understand much better now.

 

[ktb]

the way i've alway under stood it the pump creats flow and the restriction creats presure

 

[sag2]

The eccentric shaft (CP3) is free in 1 position until it is under load. . Under load the geometry is equal. There is No load or unloading,once fuel enter the HP side the holes are always under pressure. Can someone point Me to the devise that regulates the Pressure on any CP3? its NOT the FCA,the FCA controls Volume. The noise I hear is completely related to combustion.

Todd, I hate to differ with you, but the recording was made before and after moving the pump shaft 30 degrees per a Cummins procedure. If it was combustion related, what difference would it have made moving the pump? I think the results on the recording speak for themselves.

 

[WalterJ]

I'm not familiar with fluid damper construction, but have some experience analyzing machine "vibration". Is it possible that the time element is related to internal fluid temperature and viscosity, thus contributing/causing cavitation within the damper?

Kudo's to those working so diligently to resolve this important issue. Good luck.

 

[TCDiesel]

Todd, I hate to differ with you, but the recording was made before and after moving the pump shaft 30 degrees per a Cummins procedure. If it was combustion related, what difference would it have made moving the pump? I think the results on the recording speak for themselves.

I have build over 2000 pump (CP3s) dealt with 1000s of pump related issue's And I have NEVER suggest to rotate the gear to resolve any noise... What I have found is emanate failure if repairs are not performed on any CP3 that is noisey. Yep. . I have been told that they rotated or clock the position,but the pump eventually made its way to me only to find the real cause.



No doubt wired things happen. . but its Not the norm. . nothing wrong with performing the clocking. but check with Comp/CF/DTR or any builder, etc, many have performed this and the results did not change the rattle,(or only change for short Period of Time), eventually it returned... this did verify that the cause was the pump. Repair or in most cases replacement of the pump was needed.



If you like to verfied. . with engine cold and you have the tools to correctly raise rail pressure. . Now the pressure changes will differ on selected year. raise the pressure to lets say 8. 300psi 03/04) when cold the engine will not knock, Waite about 30 seconds and it will start to knock,Now Waite 24hrs raise the rail Pressure to 9. 300psi Cold,in 30 seconds it will knock the knock will be in same time ,but it will be more pronounce etc. So this confirms that pressure and temp effect timing on all CR engines. I have heard it stated that pressure does NOT have any effect on timing by some of the popular EFI tuners.



FD call me I will equip you with the correct device(s) to lower the rail at idle. I bet the noise will disappear at 3. 800psi 03/04 ,it will lope but the noise will be gone.

 

[TCDiesel]

Todd, I hate to differ with you, but the recording was made before and after moving the pump shaft 30 degrees per a Cummins procedure. If it was combustion related, what difference would it have made moving the pump? I think the results on the recording speak for themselves.

Todd, I hate to differ with you, but the recording was made before and after moving the pump shaft 30 degrees per a Cummins procedure. If it was combustion related, what difference would it have made moving the pump? I think the results on the recording speak for themselves.

I have build over 2000 pump (CP3s) dealt with 1000s of pump related issue's And I have NEVER suggest to rotate the gear to resolve any noise... What I have found is emanate failure if repairs are not performed on any CP3 that is noisey. Yep. . I have been told that they rotated or clock the position,but the pump eventually made its way to me only to find the real cause.



No doubt wired things happen. . but its Not the norm. . nothing wrong with performing the clocking. but check with Comp/CF/DTR or any builder, etc, many have performed this and the results did not change the rattle,(or only change for short Period of Time), eventually it returned... this did verify that the cause was the pump. Repair or in most cases replacement of the pump was needed.



If you like to verfied. . with engine cold and you have the tools to correctly raise rail pressure. . Now the pressure changes will differ on selected year. raise the pressure to lets say 8. 300psi 03/04) when cold the engine will not knock, Waite about 30 seconds and it will start to knock,Now Waite 24hrs raise the rail Pressure to 9. 300psi Cold,in 30 seconds it will knock the knock will be in same time ,but it will be more pronounce etc. So this confirms that pressure and temp effect timing on all CR engines. I have heard it stated that pressure does NOT have any effect on timing by some of the popular EFI tuners.



FD call me I will equip you with the correct device(s) to lower the rail at idle. I bet the noise will disappear at 3. 800psi 03/04 ,it will lope but the noise will be gone.

 

[Prairie Dog]

I've been in the auto repair business for 34 years now, not in diesel repair, but primarily German autos, and have learned enough and seen enough never to discount another idea. The CP-3 noise certainly is a possibility, but when listening to mine with a stethoscope, the actual source of the knocking noise appeared to be loudest right in front of the FD. I used an ordinary (non-electronic) stethoscope with the probe removed, just the open airtube, so that I could listen up close to the rotating components and not make contact with anything. My intuition would be that if the FD smooths out the firing pulses, wouldn't that serve to reduce pressure spikes from the CP-3? Don't know the answer to that one, just looking for answers.

Agreed, some answers to this would be very welcome.

It's a very metallic sound and nothing at all like anything I'VE ever heard come from combustion.

When I get my ear down against the radiator I find the sound is very specific in origin. As I follow the sound it becomes loudest directly in front and maybe slightly to the passenger side of the FD. I cannot hear the sound at all on the top or sides of the engine. I have run the eng without a belt and it's still there.

 

[Joseph Donnelly]

Check the bolt heads. Unless things have changed, they are grade 12. 9 and should be torqued to 92 ft-lb. No torque and turn is used; that kind of bolt will have an angle mark on the head and the degrees shown, like <90. The bolt holes in the crank don't go all the way through the carnk; they are deep but blind.

 

[TCDiesel]

This is video of the internal movement of all CP3 Dodge applications... As you will see it always Stops @ 10 O clock always,once install it will stop open.

My Movie - YouTube

 

[Prairie Dog]

Check the bolt heads. Unless things have changed, they are grade 12. 9 and should be torqued to 92 ft-lb. No torque and turn is used; that kind of bolt will have an angle mark on the head and the degrees shown, like <90. The bolt holes in the crank don't go all the way through the carnk; they are deep but blind.

We'll have to disagree on this one though I always enjoy your writings very much. The FSM says 37 lbft + 60 degrees (as did a Cummins PDF I found on-line) and that is what I used for both the FD and stock dampeners.
I looked for evidence of movement around the bolt holes on the FD after I took it off and found none.