Okay, i just got a 96 maxima, and i am currently changing all the gaskets, in the mean time, my 92 rs 5.0 will be my daily driver. As it has been. Well. This morning, i went to o'reilly to pick some other stuff up. I went inside, leaving her running and when we left i noticed a loud knock randomly appeared as i took off. And as fast as it appeared, it stopped. Even when revved it doesnt do it. Theres no power loss or anything. My mom had a 1983 scottsdale pick up, and she said the valves clattered, and from what i remember of the sound, ive been hearing that noise for around a year. And now it randomly starts knocking and stops, what could do that??? Thanks!

 

how loud is the knock? Does it do it when you first start the car and then go away?

 

Loud enough to hear over the radio, ac all the way up, and edelbrock (sp) mufflers. It was loud enough to almost make me pull over. But as fast as it appeared, it went away. I started it about an hour later and it didnt do anything. I went ahead and changed the oil bc my bro said to. He said the oil mightve not went to the lifters i believe and to start there. NOW when idling theres a lil tap going on. Cant hear it on the driver side. But walk to passenger side and can hear it fine. And thats where the knocking came from. And even when revved theres no noise. Now, i did have a very random dead cylinder. That was MAY BE caused from a bad wire. Didnt change the wire or anything and it just stopped running rough...

 

This is weird....I too have a random knocking noise that will come and go intermittently. I can hear it inside the car , like it's deep behind the heater controls. It's a pinging that speeds up when I rev the engine. I have repeatedly tried to stop the car, get out, and open the hood to listen closer but it always disappears before I can do it. No change in performance or oil pressure when the noise is present.....cannot figure it out!
Sometimes it lasts just a few seconds, other times it's several minutes long before it disappears......hot or cold engine, it happens. Either it's not audible at idle or it goes away because I've even tried to induce it with hood up in driveway and I cannot duplicate it.

What's concerning to me is the fact that it gets louder/faster with rpms. Any feedback is appreciated as to what this may be.....don't know if this is the same as what you're experiencing or not

 

you know what, try this. add 8 oz of marvel mystery oil to your car. see if it goes away

 

I had really thick oil in the car. My brother urged me to change it so i did. I still have a tapping tho. Im scared something messed up.

 

i told u what to do, this stuffs been around since 1920

 

I have. Ive put that, slick 50, rislone compression repair, even lukas to no avail. The taps been there. The knock just randomly happened.

 

Exhaust pipe hitting the body somewhere?

 

I dont think so. It was nice and sturdy the other day. But it cldve moved so im not sure. Also, this morning its got a random bad miss. It randomly just surge then run fine, then start surging and missing real bad, then run fine again. Thats with it in gear, foot on the brake, chilling in the driveway for like a minute.

 

Ya I would try the mystery oil it could loosen up a sticky lifter and what do you have to loose.

 

What about the pick up coil and/or rotor cap inside the distributor? Maybe that could also be why the miss/dead cylinder? I've considered this on mine too though I'm not experiencing the miss (yet). The proximity of the tapping/knocking noise while in the drivers seat of my car seems like its coming from deep behind the heater controls ...(distributor?)

 

Could it be a problem with the Dist meshing with the cam? Is the Dist tightened all the down? You might have to pull it out and take a look.