high

I am resorting to here, this is my first post. I have a 2005 2500 HD 6 Liter. Started truck a couple weeks ago at -10F heard a 'pop' sort of thing. Didn't think anything because it was cold. Then I noticed black smoke coming from exhaust. I just let it warm up for 10 minutes, gave it a...

I have a 2000 GMC Sierra SLE Z71, 217,000 Miles. The truck sat for about 8 months and yesterday I renewed the tags and changed the oil. The truck had normally ran between 40-45 on the OP Gauge, now it's idling on 45-50 and now at 40mph it's about 60. I don't remember it being this high...

I've had problems with it before but I've started to notice it more, that its running at too high rpm for only going 35 to 45 mph. I was going up a hill at 40 mph and it was running at about 2500 rpms. My idling rpms is about 1500. It's an automatic, and it just doesn't seems to be shifting...