99 Yukon

[skodiak88_99Yukon]

Any info would help please. A couple mechanics told me I have a misfire and a valve might be down. It is hesitant to start and feels like it is going to turn off and die if idle or in park. But if normal driving it seems ok. Not like my truck was but when I'm driving it's not acting up. If I a sitting at a light it sounds like I have a loud ass cam. Any ideas???

 

[skylark]

It sounds like it is time to do a compression check. Your highest to lowest numbers should be within 10% of each other. Look at the spark plugs as you pull them out, they should be a light carmel color. If the compression checks good and the plugs look good then I would start checking for vacuum leaks.