My Durango would occasionally read zero at idle. Didn't think much of it as I didn't hear any ticking, etc. It's got a lot of miles on in, and I don't change the oil like I should. Assumed it was just the sender. At some point I finally changed the oil on it and a few months latter, I realize the gauge hasn't acted up in a while. Guessing I had a bad filter. That was probably a year or two ago, and now I've got 300K on it. For what it's worth, I think it was a Puraltor filter on it.