My brother and I both drive '05 CTD's. This past weekend I was in his truck and noticed that his tach' indicated 300-400 RPM at idle and the engine was obviously running faster than that. We drove for a bit and the tach was clearly indicating a few hundred RPM low. Then after we stopped for lunch and got back in the truck, the tach' appeared to be indicating the correct RPM (around 750 @ idle). He says it's been intermittent like this for quite some time.

I know there have been reports of tach' and gauge problems in the '06 trucks, but I haven't head of issues with the '05's...

Anybody have a clue what the issue may be or how to fix it??

Thanks in advance!
-Mark

 

My 06 tach flips out from time to time. Mostly at idle. Didn't know there was an issue. I caulked it up to the Viper Alarm / Remote start install guys. Any known cures?

 

You might try contacting these guys: www.mrwhizard.com
They say that they can fix '06 dash issues... though they said they couldn't repair my brother's '05

 

I'm still looking for a solution for my bro's tachometer... he's reporting that the tach is still reading low (400 @ idle) and the transmission is shifting (locking up?) early.

There are no engine P-codes or C (cluster)-codes and the gauge check seems normal.

Any chance this is a cam position sensor? Crank sensor? What about that wire that gets chaffed on on the A/C compressor? Anything else we should be looking for?
Thanx
-Mark

 

I would gladly accept a low reading tach for the ability to lock up the transmission earlier than 30 MPH. Are you sure you want to "fix" this?

 

Anybody know of any other things to check for? Mine was running about 500 rpm's low most of the time, but would pick up to normal occasionally when accelerating. Now, it reads closer to 1000 low all the time, if it reads anything at all.