Hey guys, looking for info on if anyboady has expereinced any bad knocking sounds comin from their truck. I have a '96 3.9 dakota sport. Sounds pretty rough. Any ideas? Thanks

 

how bad of a knocking is it? and when was the last time you did a tune up on it.

 

It's been getting progressively worse. sounds like a broken rod!! It's been running like crap too. I haven't done a tune up in a while. I just did the air filter, pcv, and oil. sounded better after that. But now it sound slike she's on her last leg. Should i take a look at the cap and rotor? When it's damp out the truck won't start until I floor it. Somedays when I start it, it smells like raw fuel out the exhaust. ??? I did the plugs 3 years ago with the platinum ones.

 

the 3.9's are known for the timming chain to get slack in it and slap around. mine does it and I have to give her gas to start it too. and at idle all you can hear is knocking and rattleing. that might be your problm... I dont really know.

but I would do a complete tune up and see if that helps. cap, rotor, plugs, wires. I did all that for mine under $100

 

how would you describe the sound deep metallic rapping or more like a solid thudding cuz if its rapping I don't think a tune up is gonna help

 

Push rod or connecting rod?
If it's valve train noise, you might have a dirty/sticking (vice collapsed) lifter. Tryadding an oil detergent, like CD2, or some Sea Foam in hopes of freeing it up.
Regards,
Greg

 

Sounds like a ticking noise. Continues on at all rpm's. I put some Lucas oil stabilizer in, that helped a bit, but it's back. I doubt it's a connecting rod, 'cause I'm sure it would've poked a hole in th eblock by now, no? She goes through oil pretty quick too. Can i check the pushrods and such by taking off the valve covers? Should I do a compression check?

 

I would do a dry and a wet compression test.