I'm not sure if the engine was knocking, but myblazer started jerking and i heard some noise. But it does that periodically.What could be the cause of that.

 

i have no idea but u need to put some details. what year and model is your blazer? when does it do that? how long/ loud/ harddoes it do that?

 

I have a 1989 s10 Chevrolet Blazer 4x4 2.8L V6. It only makes jerks like once every few minutes. No sounds just jerking of the vehicle

 

You still havent given enough info, this could be literally dozens of things based on your description.. ranging from engine/tranny problems to suspension/chassis parts being broken and/or worn.

Unfortunately the 2.8s were pieces of junk to begin with. It could be a misfire, whens the last time it had a tuneup? Plugs, wires, cap&rotor... maybe a vacuum leak could explain why its doing it periodically?

 

I have only had it for 4 months. I dont know when it has had its last tune-up. It just jerks makes no noise at all, only jerks once every few minutes. It has a new engine that is no more than 6 years old. So it may just need a tune-up. But what would cause it to jerk. Can you just please give me an idea, so i can get it looked at.

 

A misfire in one cylinder is enough to make some unGodly shakes and vibrations, but if you aren't mechanically inclined, you may take it to a shop for a more informative diagnosis.

Perhaps you could check the motor mounts?

 

I figured out what it was. I was leaking oil through my valve covers underneath my cyclinder heads. I replaced my valve covers and replaced all my spark plugs 4 out of 6 had oil on them because of the leak. Then I replaced the wire set and I also replaced the distrubuitor and the cap. It runs fine, all it needed was a tune-up.

 

I dunno if my 2.8 in my z24 is exactly like a blazers 2.8 but that engine kicked a**. Always started up........thats at -50*C without the block heater plugged in, and it sat alllll night.