I just recently bought a 1990 z28 and the engine knocks fairly loud, i dont really know all that much a about cars, i was wondering what i would have to do to get it to stop and the cheapest way to accomplish that. Also how long would i be able to drive it until the rod in the engine shoots all the way through??


thanks for any help

 

If its rod knock, you need to get a bottom end rebuild. Sorry bro.

 

thanks for the reply, would i be better off rebuilding it or just getting another engine to drop in??

 

305 or 350?

- Justin

 

neither of those, i do know that it has a 3.1 liter V-6 if that helps, i just want to know if i can at least drive this thing like 10 miles

 

Well first of all, it's not a Z-28 then. I'm not positive on this, but I believe chevy made 4 models in 1990. They made the IROC-Z in coupe and convertable form, and the RS in coupe and convertable form. Chances are you got an RS with Z-28 badging that the guy must have slapped on the car, because you couldn't get the 3.1 V6 with the Z.

 

10 miles with a rod knock? Try it out and tell us if you made it.

Honestly, No. It should be pulled and have the motor yanked. Plain and Simple.

 

How bad is it knocking? I've drove them where it was ticking pretty nice, but never when they started to knock. When it knocks it's time for a rebuild.

 

I just drove mine 20 miles on Saturday with one hell of a knock. That said, the engine is now on an engine stand and will be a (hopefully) 450 hp/tq 383 stroker by the end of August.

 

This isn't a SBC guys, it's a 60* v6

I drove my '85 2.8L Camaro for 6 months (4500 miles) with the #4 connecting rod bouncing around on the crank. I wasn't nice to it either. The rod never broke, it just got so bad that the car wouldn't move well under it's own power, so I sold it.

Unless it has been that way for a while, go ahead and drive it (gently) for the 10 miles - you should be fine.

- Justin

 

thanks for all of the help, also what all do i need to replace when i go to rebuild the bottom half of the engine to fix the knock

 

You'll need to have the rods checked, and replaced if necessary, the crank may be saveable, you'll need a full bearing kit, all new gaskets. You'll have to tear the motor down and see how everything looks.

Were you planning on doing the work yourself? Do you know of any good machine shops?

- Justin

 

no i'm not gonna do it by myself i have a buddy of mine helping me, he's pretty knowledgable about this stuff cause he tears his 460 big block down all the time, i think i'm gonna start ordering the parts now so i can hopefully fix this problem, then later on down the road i'm gonna go for a supercharged 350

 

Well, if you are saving for a 350, tear down the 3.1 before you order parts. That way you know what is bad before you start spending money.

Just an FYI - I spent just over $900 to rebuild my 2.8 (no labor costs since I did it myself, and a very cheap rate to have the rods checked at a local machine shop). Make sure that all of the oil and coolant passages in the block are clear before you reassemble, I had a blocked oil passage in my 2.8 that caused the need for a rebuild in the first place.

- Justin

 

yea i'll do that, i just hope that i dont have to spend $900 on it cause i'm only 17 and havent gotten another job yet, but i looked up the price for the bearings and the crank and it doesnt seem to be all that much