I have a 2006 ram with the hemi and for the most part now it just sits, I keep it under a cover in my drive way and after sitting 3 weeks to a month i took it out for the weekend and i noticed when the truck was idleing the tach would slow go down from its normal idle to about 200 rpm but as soon as i rev it or take off the tach reads correctly... any ideas???

 

Old gas

 

even with fresh gas it does it... but it runs fine which is the weird part too... the tach is just way off at idle

 

I have this exact problem and it has nothing to do with Gas.. It's my daily driver. Idle SOMETIMES drops to 200 and I notice it slipping even at speed. No idea how to fix it, and the truck runs normal so I'm not going to take it in until I'm completely annoyed. Anyone have a fix for this?

 

What it could be is the white guage face slowly moving outwards and resting on the needle of the tach. We had an 05 srt with a similar problem so we took apart the cluster and pushed the facia back a little bit to how it would have originally been and problem was solved.

 

Can you tell if the truck really does idle that low or do you think it's a problem with it being reported wrong on the tach?

 

Tach is wrong. It also happens at highway speeds. I'll be doing 75 and can watch it hold around 2000 then it will start bouncing all around and then jump back to 2000 and it is definitly not actually happening. I will try to see if it is the cluster problem, thanks for that suggestion.

 

I have a 2006 Ram 2500 (diesel if it matters) which does similar...shows almost zero rpms at idle, even though it is idling normally. At the other end, it shows me over red line (3500-400 rpm) when I'm "gently" passing someone...I mean, I'm not getting on it and it looks like I'm about to blow the engine. I assume it's wrong on both ends, but thought I'd chime in just in case someone had a fix or an idea?

Thanks,
Jim

 

Sorry to bring back an old topic but I'm having the same problem.

I just got an 06 Ram Laramie, and noticed the tach dropping down at idle to about 100rpm or less. It is also kinda jumpy from 1000-3000.

I had it at the dealer today to have my improperly balanced tires looked at, and of course it would not do it on our 30min test drive.

Did you guys ever find a definite solution?

 

My tach seems to have corrected itself, although it may not be totally accurate still. I have no idea what was different then from now, but it now idles at 300-500 rpm, and cruising down the road I'm in a normal looking range of 2200 rpm.

An odd thing happened awhile back worth noting, although I don't think it is related to it fixing itself....I looked down and the rpm needle was on the wrong side of the gauge, like it went "over the top" and was resting on the backside of the little needle that stops it at zero. It was as if I ran the rpms so high that it went completely around the gauge and couldn't get back. I do not run it hard, and no one else drives my truck, so I know this is not the case. What's just as odd is that it ALSO corrected itself. I don't know how or exactly when, but I looked down recently and it was back to the normal side. Odd??
What I cannot recall is if, when it got back to the correct side, did the rpms begin to also indicate correctly (or nearly so....I'm not so sure that the idle rpm is really right, seems low to me)?

I doubt this will help anybody, but thought it interesting enough to post.