1990 Chevy Silverado smoking and engine clanking

JESUSFREAK0791

MEMBER
1990 CHEVROLET SILVERADO
V8
2WD
AUTOMATIC
156,467 MILES

I got this truck when my great grandfather passed away. It had been smoking before I got it and it sat in my aunts back yard for about two years and cranked maybe once every two months.

When I finally got it I replaced the sparkplugs, air filter, oil filter, and oil. It was still smoking and was letting off white or blue smoke can't really tell. It makes a knocking noise when it's being ran and it smokes a good bit. I've heard various things that could be wrong with it so I wanted to get a professional opinon on the matter.

It has a hard time idiling and the truck likes to jump a little also when I'm not moving.

Any opinions?

1 Reply

BLACKOP555

MECHANIC
10,371 POSTS

White smoke=water in the gas and you should drain the tank and the lines and fuel filter and fill it with fresh gas and see if that helps it drive better and the white smoke to go away, if that doesnt help it may be a blown headgasket, and you should perform a compression test on all cylinders.

As for blue smoke, that means oil, and a compression test will help you know if its has bad valves or rings also.