Engine/Transmission (1998.5 - 2002) VP44 and 2K rpm drone

[tmccormick]

Hello everyone, new to the forum.



Been lurking longer than I would like to admit



Anyway, I have what seems to be a possible problem. For the last 3 weeks my VP44 seems to change "pitch" when the engine reaches 2000 rpm and I get what I think is exhaust drone which I havn't had up untill the same 3 weeks.



The lift pump still runs for a second when the ignition swich is turned on to start the engine. The performance doesn't seem to be lacking just the odd pitch change and drone.



Could this be a precurcer for LP failure or possible a bad VP44?



Truck is a 2001. 5 ETH/DEE Quad SWB all stock.



Oh, I'm taking the truck in to the dealer tomorrow for a test drive to see if they hear what I hear... whish me luck

:-{}

 

[dodger22]

I have the same problem but it is only noticeable when hauling the 5'er. The resonance starts at 1900 rpm and goes at 2100

I found that I could "feather" the throttle past that threshold and avoid it.



I posted the same question on this board months ago and basically the answer I got back was it was exhaust related and not to worry about it. It can be a bit aggravating though.



Richard

 

[tmccormick]

dodger22, have you always had that drone or just started up?



Yea, I can sort of make the drone not so pronouced if I just apply more throtle and rev past the 2K mark. But the change in VP44 pitch is still there. This is with NO load.

 

[Idaho Native]

t,



Have the same indications with my '99 since it was new. Only noticeable when it's very cold outside. Loaded or unloaded. Runs absolutely fine. Factory lift pump went kaput... no change to noises with the new one installed.

 

[dodger22]

tmccormick



As I recall the drone started about a year after I bought the truck, but that was when I started to pull a 5'er. I have put many miles on since then with no problem, well with the exception of the LP of course



Richard

 

[ihegdal]

I also have a noise between 1800-2000 RPM. At first I thought it was the engine surging, but for the most part I don't feel the surge as much as I hear it as an engine pitch change. Truck is an 2001 ETC. The symptoms are present with or without the EZ connected.



I took the truck into the dealer and had the shop foreman take it for a drive. His comment was that it sounded like the pump timing was changing (oscillating) back and forth. They checked things over but did not find anything definite.

 

[tmccormick]

I took the truck into the dealer and had the shop foreman take it for a drive. His comment was that it sounded like the pump timing was changing (oscillating) back and forth. They checked things over but did not find anything definite



ihegdal, thats exactly what my truck sounds like as far as the VP44 is concerned. Dealer never found nothing wrong though... imagine that Thats why I didn't take it for the test drive today... you know cannot reproduce bla bla bla. I wanted to see what you guys had to say first before I proceed with the dealer.



I just find it strange that all of a sudden I get the drone and notice the change in pump sound. I do notice the drone is alot more pronounced when the engine is not at full temp which makes me think that maybe the catilitic converter(I think I have one or is it a resonator before the muffler?) is the culpret.



I really like to find out what is making this drone sound because the truck is going to the dealer monday for a tail shaft seal replacement so they could fix that also.

 

[tmccormick]

Just wanted to give a update. Checked for any codes and it said: P PCU then Pdone. Does this mean anything?

OK I did a search on codes and I guess it means there is nothing in the PCM part. After the P done comes up does the ECU part then displayed? If so I will check that part next (I"m at work right now so I will check this in a little while).



It is a little warmer here today and the drone is a little less pronouced but if I had to drive a long distance at 70-75mph the drone would drive me nuts. Heck you can feel the vibration/hum on the floor board and steering wheel! I can take the truck out of gear going down the highway at 70+mph and I don't feel nothing so I don't think it's in the drive tain.





I din't know what else to do but take it to the dealer:{

 

[Diesel Freak]

Originally posted by tmccormick

His comment was that it sounded like the pump timing was changing (oscillating) back and forth.

BINGO... but that will have nothing to do with exhaust drone.

 

[tmccormick]

OK, I understand the pump wont cause the droning noise so should I assume that what it is, exhaust drone?



What about my catilitic converter theory. Could it or the muffler cause such a noise?

 

[Diesel Freak]

Your truck does not have a Cat. What you are seeing in front of the muffler is a resonator.



This "drone" you are talking about, is it a resonance that occurs inside the cab, or is your exhaust just getting louder under load?



the Pdone means you do not have any trouble codes set in the PCM.

 

[Houser]

Might be Nothin

Hi Again

About your mystery engine droning noise. My 02 HO does the same thing at those HWY speeds. I blew it off thinking it was the tire hum resonating with the engine rpms.



Houser

 

[CumminsDZL]

Originally posted by ihegdal

I also have a noise between 1800-2000 RPM. At first I thought it was the engine surging, but for the most part I don't feel the surge as much as I hear it as an engine pitch change. Truck is an 2001 ETC. The symptoms are present with or without the EZ connected.



I took the truck into the dealer and had the shop foreman take it for a drive. His comment was that it sounded like the pump timing was changing (oscillating) back and forth. They checked things over but did not find anything definite.

my truck was doing the exact same thing. it was storing code 1693 i believe, which is injetion pump timing failure. when i took it in with 88000 on it the dealer was very helpful and installed a new vp44. i had my truck back in two days.

 

[tmccormick]

Hi all, OK I have no cat just the resonator. Glad to here that others have the same noise goin on at those rpm's. I find it strange that it just starts up out of the blue. Had the truck since July 01 and never have had this noise till 3 weeks ago.



So can anyone give me a good explanation as to why it just starts up?



I'm not concerned about the pump ocsillation being there isn't any codes stored and it seems to run fine.



By the way this isn't my first CTD, Had a 93' 5spd, a 96' 5spd and now the 01' so I'm not a "newbie"





Thanks for all your replies, tmccormick.

 

[Smokewagon]

I don't know what you guys are calling a "Drone" sound, unless it's the regular low "common" cummins sound. I too have a noise I hope for my sake we are having the same problems only determining what to call it. Here goes... ... . My truck has (3) distinct sounds. The regular diesel low pitch "Drone", I can hear the turbo spool up under acceleration, and finally the one that is driving me INSANE is a hammering sound that sounds like it is audible from the center of the steering wheel to the immediate left. It's not the lift pump or the 44, I had them changed and pressures checked and rechecked. I too have a vibration that is definately THERE in the go pedal. A strange thing is that when I activate the cruise it seems to quiten down greatly, but doesn't completely go away:{ I am stumped, ticked, aggrevated, P. O. ed and so on. All this doesn't help, but I know that it DEFINATELY was not there untill about a month ago or so, and is getting progressively louder. I am taking mine back to the dealer and they said there is a switch/solenoid or some kind of contraption that STAR has to approve to let them install that controls the throttle linkage function that is affixed to the cruise. I'm gonna let them change it, hopefully they will find out what it is before I get really mad and go get a new PHERD! NOT!! Anyway I'll keep you guys posted.



P. S. I'm not on medication and I have great hearing



Dave

 

[tmccormick]

smokewagon, the only way I can explain it is the familiar Cummins "hum" but louder at 1900-2100 rpm. Like I said in a previous post you can feel it vibrating the go pedal and floor board.



Only thing I can say is it is less pronouced as the outside air temp goes up

 

[rfletcher10]

I HAVE A 01 2500 HAVE THE SAME DRONE AT 1900- 2000 RPM IT GETS VERY LOUD UNDER LOAD . (IT STARTED WHEN THE TRANY WAS REPLACED (THE OLD ONE HAD A BLOWN FRONT CLUTCH PACK. ) THE DEALER SAID IT ONLY MADE THE DRONE WHILE IN OVERDRIVE. SO THEY THINK IT IS THE OVERDRIVE AND ARE REPLACING THE TRANY AGAIN. SO WHAT DO YOU THINK ARE THY ON TO SOME THING? R FLETCHER (ROBBIE)

 

[Gary - K7GLD]

HMMMmm - never have heard ANYTHING that sounded like it was coming from the VP-44, but I *do* get a noise at the exact RPM's as you other guys, but mine sounds FAR more like a vibration/resonance/buzzing somewhere in the exhaust system around the muffler or resonator - wonder if we're all talking about the same thing, and wonder if guys who have removed their mufflers or switched to entire larger or different exhaust systems still get the same effect? Mine seems somewhat reduced as miles increase, but it's still there...

 

[dodger22]

GaryKJ6Q - See my earlier post. Mine is noticeable when I'm hauling the 5'er - about 10,000lb. I can "feather" the throttle past the rpm it occurs at. I do this by slowly working up to the speed and ease off slightly, then give it some more "gas", ease up and so on. I would describe the noise as a resonance more than anything else. Does yours occur when pulling a trailer or solo?



Later,



Richard

 

[tmccormick]

rfletcher, sounds like you have a auto transmission. Interesting that the dealer is saying its the OD.



I still havn't moved ahead with this strange hum,drone,vibration (NOT the normal cummins hum) thing with the dealer because I just want to drive it to see if it gets any worse, which it seems that it is.



Now that the weather is getting warmer out it seems to be more pronouced. I will be towing my boat in for the summer maintenance soon and that will be the first time I have driven the truck with a load. Can't wait to see how it acts then





I wish I had never added the part about the VP44 making the ocsilating sound because I think that kind of made the board think it's a engine issue (engine runs strong) but the more I drive it I think it's in the transmission or maybe the pilot bearing.



It ONLY makes this terrible sound, vibration when the engine is at 1900-2100 rpm, any gear but a LOT louder while in 6th gear going down the highway. Also I might add when crusing in 6th at that rpm and then mash the go pedal it REALLY sounds bad and maybe it's just me but it seems like the truck feels like there is something holding it back while it is accelerating



Don't know what else to say but I would like to get this resolved before summer hits and time to start pulling the 5th wheel again.



If I new that this is comming from the exhaust then fine I can live with that but I find it strange that it just happens one day after driving it since new for 20k miles.



Again thanks for all the replies, tmccormick.