I've been noticing my '92 S10 Blazer 4x4 is running knocking when it idles sometimes. Also, there's a decrease in acceleration and sometimes it will hesitate a bit.

I bought some new oil and a new oil filter today and also a can of Seafoam. I recently changed the oil about a little over a week ago and put maybe about 40 miles on it.

My main question is how do I use the seafoam I bought? Do I just put it in the crankcase right now or should I change the oil and then put it in? I'm not sure since the fact I've driven it for a bit would make a difference, but there are a lot of knowledgeable people on here and I thought I would consult all of you.

 

If you are going to use it in the crankcase, then dump it in and drive it for a few days (at least 100 miles), then do an oil change like normal.

Knocking at idle is not good...

 

Thank you.

Yeah, I've had my Blazer for a year and seven months and it's been great to me. The only thing that has gone wrong was the fuel pump. I've been incredibly lucky. But, I think it will probably die soon, considering that it has a lot of miles on it and Michigan winters are harsh.

Time to look for something new.. Even though I am a poor college student..