Fluctuating tach readings

[KMNixon]

Just bought first diesel 2006 quad cab LB auto and have experienced fluctuating tach readings with no corresponding actual engine speed changes including idle readings of between 400 and 700 rpms - no codes being read.

 

[mberry]

Welcome to the TDR!

We need some more information in order to help more. When was the fuel filter last changed? LOF? Miles on truck/engine? Stock, or modified engine and/or transmission? Stock fuel system? Any details you could provide would be extremely helpful.

 

[brad k]

mine does the same thing, it is in the dash and the whole thing needs replacing. several people on here have had it in their '06 models and have yet to find the actual problem, but the dash is all electronic and very expensive, i have chose to live with it. will not have any effect on the performance of your truck, just drives me crazy to look down and see it redlined when it really isnt

 

[jdbecker2]

I am not positive, however when I got my truck reflashed for the long crank issue, there was also a note that the flash fixed the tach also. I didn't notice the problem before (doesn't mean it wasn't there) but it's certainly not present now.

 

[JoshKelly]

My father's stock 2006 Megacab had this problem as well. A new gauge cluster was put in at around 40k miles and has been fine for the last 20k miles. Luckily it was under warranty at the time or i'm sure it would have been an expensive repair.

 

[JFought]

yup they replaced mine at 60k under warranty

 

[KMNixon]

Pretty much the responses I expected and feared. mberry it is completely stock with 69500 miles and fuel filter, air filter and oilchange done at 67,500.

Thanks

 

[Missouri Mule]

My Freightliner's tach has been all over the place for many years (cheap gauge).

 

[JordanB]

Mine does the same thing. Might see if they'll replace or fix when I send it in for a leaking CP3 pump.