Just this week my truck started doing something weird. I first noticed it on Tuesday but then I wondered if I was just seeing things because I could not duplicate the symptom again. Didn't drive that truck yesterday but this morning same thing happened.

At first start, the engine fires normally yet the tach needle rests solidly at zero for about 15 seconds, then it pops to life. I shut the truck off and restarted the engine a few times and the needle responds normally. So far today it's been normal....just the first start of the day has the weirdness.

Has anyone seen anything like this before? What could cause this issue?

 

My fuel gage will do that sometimes after filling up (it never used too). I know my tank is full, but it will read 1/2 -3/4 for a while before it goes all the way up.

 

It just seems odd that it only happens on the first start in the morning....I suppose it's temperature related. Temps here in the morning are in the 70's so maybe the symptom will worsen the colder it gets...

I have a spare instrument cluster somewhere...I'll try and dig it out to see how the needle functions. I presume there is a counterweight that reacts to a magnetic field but I am only guessing since I've never looked at the gauges that closely.

 

My tach periodically does the same thing but my solution is simply to give the dash (on top of the tach) a firm smack. I hate to say it but it solves the problem every time.

 

Yup!! Nothing like a jolly good "bashing " mate!!!

Smokie