Low Knocking Sound in 88

[Sultan]

Just got the truck a few days ago and it runs great. No smoke fest on startup.

What I have noticed is under acceleration I get a low knocking sound. I think most folks won't notice it unless you were listening for it. At speed it goes away.

So I am looking for opinions. Is this an engine mount or time for a rebuild?

Thanks. Rick

 

[Sultan]

Forgot to add that it is a 2.9 with 208K miles on it. No idea if it has been rebuilt before.

 

[adsm08]

Check your timing before you do anything. Kinda sounds like spark knock to me.

 

[heptofite]

sounds like your mains are worn.