01 Tach that quivers

[CTabor]

Does any else out there have a 2001 2500 5 speed that the tach is always moving up and down 50 to a 100 rpm. asked them to fix it at the dealer the mechanic said he had driven three diesels that day and they all did it. He also said he called D. C. and the said this was acceptable. The pickup is only 4 days old 1500 miles.

 

[MCummings]

I don't have a 2001 2500, but I have a '98. 5 3500, and the Tach has jumped up and down at idle since new.

Over the years, the tach has started to "quiver" more slowly than when it would jump up and down when new.



MerrickNJr

 

[Big White Beast]

Rock steady......

Been that way for over a year now. Sounds like the stealers just don't want to put the effort into fixing it



Doesn't sound normal in my opinion.



Garrett

 

[chuck3]

Tach.

My y2k tach. will move around about 50 rpm's or so and so does a friend of mines.

 

[Doc Tinker]

I think what you guys are noticing is the diesel engine's inherent roughness, for lack of a better description.



There is aways a slight difference in the injector spray patterns, from one injector to another, which can cause the engine to pulsate. This variation can be caused by unmatched injectors, carbon build-up on the injector tip and maybe even air bubbles in the fuel.



A slight osculation, at idle, is not unusual.



When I replaced my stock injectors with 275s I noticed a significant change in how smoothly the engine ran at an idle.



Doc

 

[RustyJC]

Yep, the tach needle is jumpy on my 2002 as well. I really don't think the engine RPM is varying - just looks like noise in the signal to the tach. Interestingly enough, the tach in my 1996 V-10 was rock-steady. Go figger... .



Rusty

 

[DAWG-1]

Tach has varied 50 or so rpm since new. I would rather DC not mess with my truck, it runs fine. Sam

 

[ROCK KRIES]

My 2001 Auto does the same since new, when you drop in gear with the brake on it is rock steady. It is just the big beast breathin.



ROCK

 

[big barney]

My truck has done this since it was new. When the motor is cold it is rock solid. The hotter it gets the more the tach jumps around. When I put the 275 injectors in it seems to be worse. Took it to the dealer and they said it was normal, what else is new. Truck runs great otherwise.

 

[LMautone]

my y2k tach jumps slightly (50rpm) at idle when engine is warm since new. truck runs flawlessly---don't worry it's normal

 

[LBTRS]

Mine does it also

Mine jumps around 50rpm both ways at idle, must be normal.

 

[Ramafid]

Ditto on the tach jumping +-50 rpm. I think it got worse when I installed the 275's also. Seems to be " Normal".

 

[big barney]

If the tach jumping around is normal why don't they all do it? I've been in at least 15 other trucks and none of them did it. What is the difference between a jumping tach and one that is rock solid? Why is the tach solid when cold and then as it warms up begins jumping around?? I know you guys say it is normal, but it still bugs the Heck out of me.

 

[RGRAT1618]

My 2001 has been doing it since I got the truck. I took it to the Dealer and they said it was normal.



Rob

 

[Lurch]

Mine jumped when I got it, stopped with the EZ, started again after I did banjo bolts, go figure.



Lurch

 

[Floor It]

The reason that most all the trucks do this is because dodge now use's a electronic system that is based on sample reading. The reason they did this is the older system was too touchy and would go up and down with any variations and the cruise control would surge on some trucks really bad. Personally the system they are using is junk because it doesn't sample read enough times per second, IMO.