So.. Car starts right up fine. i hit gas, it knocks like crazy, dont hit gas, i hear nothing, hit gas i hear it knocking

im assume about to be a blown rod? or already a blown rod?

A rod bearing has most likely failed. Typically you'll hear knocking start just as you have described. It will knock once revved, especially as the rpms start to come back down. The most noticeable knock will come just as the rpms reach max, and start to drop again. The bearing tolerances have worn enough that now the rod has some slop on the crank journals.


Next step is to mash up some bananas, throw them in the oil, and sell the car "as is" haha

This post was edited by OldAndyAndTheSea on Jul 8 2017 05:42am

imo= Big difference between bearings causing noise and some old school flat tappet cam engine lifter knock. My Jeep 4.0L knocks for a few seconds on cold start, running 10w30. If I run 5 weight oil with some mystery oil, the cold start knock goes away. What I've researched, the 4.0 Jeep engine is notorious for this.

The bearing knock on my old 3.8L Olds completely locked that engine up after I put the gas to the wood......stupid me. Only recommendation to OP = drive and accelerate very slow.

This post was edited by said_aouita on Jul 8 2017 08:56pm

My Z knocks on cold starts, but that's because the silicone content in my pistons are almost non-existent.

But for real, sounds like you spun a bearing, and it's closer to letting go than you think.


Drive it until you put a hole in a the block.

thanks for the info. it was weird when it happen..

i was driving 35-50 in the city, next thing i notice i lost all power to car, i pull over, car refused to start back up at all. had it tow to a friend house, cause i wasnt paying an extra 400$ to tow it to my house.

now it starts, but this massive knocks only starts when i hit gas, guess. time to retired the fiero =`/

worth more parting it out then selling it as-is



This post was edited by WinSomeDoh on Jul 10 2017 11:03pm

find a super charged 3800 and drop it in there

bump

Why so he can make a 190 horsepower out of a really heavy motor?

they may be that stock but they respond to mods very well