Erratic tach
- Thread starter RHeller
- Start date
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Hemi395
Senior Member
- Joined
- Mar 18, 2013
- Posts
- 8,987
- Reaction score
- 15,663
- Location
- Cape Cod MA
- Ram Year
- 2013
- Engine
- 5.7 Hemi
I can't remember if it's the crank sensor or cam sensor but the tach gets it's signal from one of those. I want to say the crank sensor maybe check the wires at that to make sure it's not rubbed and make sure the connector isn't corroded.
Another thing you could do is hook up a scan tool that reads live data and see if the actual rpms are fluctuating. If not it's most likely the guage itself...
Another thing you could do is hook up a scan tool that reads live data and see if the actual rpms are fluctuating. If not it's most likely the guage itself...
Last edited:
RHeller
Senior Member
i did hook up my scan tool which does live readings. The RPMS are pretty steady, they flucuate a bit, maybe 5-10 rpms. but the small fluctuations on the reader dont coincide with the tach fluctuations at all. I am thinking at this point its just a bug in the guage itself. the truck doesnt miss a beat and idles real smooth
cody mummert
Senior Member
i just seen mine do the same thing today !
Hemi395
Senior Member
- Joined
- Mar 18, 2013
- Posts
- 8,987
- Reaction score
- 15,663
- Location
- Cape Cod MA
- Ram Year
- 2013
- Engine
- 5.7 Hemi
Well that sucks because the only way to replace the tach is to replace the entire gauge cluster which requires a dealer to flash the mileage onto the new one. An independent mechanic might be able to do it if they have the proper equipment...
