Figures, three weeks after finishing my carb swap, I start to hear a small tapping. This tapping turned into a rapping, and then knocking. Listen in and tell me what you think. Listen for two sounds, one is a constant rapping, you'll need to listen in on this, and another one is an outright knock that happens at various intervals. The noises are somewhat consistent with RPM.


http://youtube.com/watch?v=wIJ-CfNpcYg


I'm gonna change the oil this weekend to look for metallic particles, but as far as researching goes, what do you guys think I should head towards? A balanced rotating assembly with a stock 4.000 bore piston (all of these seem to have pistons included that are overbored), or a cheap short block (such as the one HERE, with the 4 bolt main upgrade). I need to be able to get this in my car on my own. I'd have the tools for it and I can get my hands on an engine hoist no problem. I'm on a budget and trying to keep $1000 my limit here.

 

definitely a rod knock,good price on that short block good luck,jimmy

 

With a 1000 limit there isent realy much you could do. Your best bet will be to rebuild the motor you have. You will most likely need a new crank (100 at Advanced Auto, comes with bearings), and eather get a new rod or get the one you have fixed.

 

I'd use some hose or a screwdriver or a stethoscope and be sure about where that noise is coming from. That erratic knock seems to be too far spaced to be a rod knock. Something just doesn't sound right about that.

Make sure to post what the problem is in the end, i'm always curious.

 

Alot of people suggested the converter bolts but i checked all of those and they were all in order.

Remember, that one random knock here and there isnt the ONLY sound, listen for the constant rapping. You can hear it better when the camera is under the car.

Man, I just have no luck huh?

 

If you didn't have bad luck, you'd have no luck at all. Thankfully, you have bad luck

 

Rod knock? I'm not buyin' it... too random. That's something else... maybe in the valve train?

I'd pull everything off the engine that I could and still start/run it in the garage.

Get a piece of garden hose and put it up to your ear to listen for the sound.

 

I think you guys are just focusing on that random knock and not the constant rapping. Listen to the last 4 seconds of the video, you can really hear the rapping that goes with the RPM there. It's not only the random knocking, theres that constant knocking too.

 

You're right, I was only hearing the random knock, but now I hear what you are talking about. If it's not an exhaust leak, it's a bad sound....

What the heck is the random knock?

 

exhaust leak??

 

No, it isn't an exhaust leak, I've had them before many times and this is much louder and metallic sounding. My guess is that maybe one rod bearing spun, and maybe one main bearing spun? Either that or something broke off and is clanging around against the crank and what not. Yesterday there was also a squealing noise too that sounded like a belt was bad and screeching, but that has gone away.

I think I am going with that shortblock in the link I provided in the first post, the four bolt main upgrade is free, so says the guy that emailed me. He said that his customers have sent him dyno sheets with power 'far exceeding' the 395hp it is supposed to withstand. I am pushing out around that, maybe slightly over 400hp, so I think I'll be in the clear. The guy has a good rep, so I think I can take a chance on him.

 

Well what you you think it is?

 

i beleive the exhaust maybe leaking but there is other troubles for sure.
the random noise makes me think the exhaust is seeping by at the collectors or headers due to the non steadiness of it. but thats just a guess im here and the car is their..

 

Drop a bolt in your intake when you did the intake swap? I have heard that before and that is what it was........

 

I don't think it would be that, it ran fine for a few weeks prior to this.

 

Unfortunately I can't see the video at work but my GTA did the same thing with the metallic squeeling sound and then went away. I don't really have a consistent knock in mine but a friend of mine told me that it could be a wrist pin. At idle you don't really hear anything but when you rev it up a bit you can start hearing the inconsistent knocking.

I'm not sure if a stuck or collapsed lifter would make that loud of a noise. I was also thinking that it may be a dropped valve but the engine is not sputtering or missing when I rev it.

I'm going to try and dump some Seafoam in the oil and run it for a while to see if it clears anything up.

 

spun rod bearing

 

After running into a random knock and a constant knock on two different car's lately ive come to a new method of finding them.

Yank the belt's off and crank it.

If it's there it's in the motor if it's not it's something up front.

 

my camaro sounded the same way last week (spun rod bearing)..i thought i would try to put another set in for a band-aid until i save up for the rebuild.but after 15min of running time the knock came back.

 

Yeah guys, I actually have a 357 short block on order from a guy on ebay. 700$ for one that can handle 400+hp. Search "357 block" to find it from a guy named 'prime-performance'. I'll post back after I get the motor.

 

You didn't take apart your engine yet?

 

How is your oil pressure? I had a pump fail on a Jeep motor and it was the pump clanking around. Definetly sounds internal though.

I dont know if I would have bought a new shortblock before taking it apart, but I have a feeling you'll make use of it. haha.

The constant knocking sounds to me like rod knock. The random ticking/knocking sounds valve train related. Im wondering...did you over rev the motor or anything? Almost sounds like the piston is touching a valve every so often. It seems more prominent on the drivers side when you are near the header. Valve train noise is amplified through headers... so I would start by pulling that valve cover. You might find a broken valve or something in there...

Good luck...let us know what happens when you start pulling it apart. Might as well get started!!

Justin

 

Have you pulled the rocker covers yet? Check them rockers and pushrods. I had an almost identical knock and it was a rocker nut that had backed off so that whenever the pushrod was in the right spot it would bang the rocker. made a random (non-rythmic) know noise. It was an easy fix with a new rocker nut.

 

Yeah guys, I didn't take it apart yet, but the thing is that I have a minimal window of opportunity to work with here. I don't have my own garage, gotta use my buddies garage and his dad doesnt want my car there for weeks on end, so I don't have the time to be taking it apart and inspecting it. I figure I have the money for the block, and I can get it in the car and have it running over the weekend.

But I have already done a checklist of things without taking the motor out of the car. I narrowed the sound to the bottom end of the motor, and I already checked all my rocker arms, checked for exhaust leaks, etc etc that whole 9 yards. It's definately from the bottom of the motor though which leads me to rod knock. The dive in oil pressure backs this up thoroughly too.

But the way I figure, it's so much reassuring to be putting this essentially brand new combo on top of a new shortblock (making about 400hp according to similar setups), and the 17 year old one it was sitting on wouldn't have lasted long, I don't think.

 

sounds like rod bearings to me ,screw in another oil pressure gauge to verify the low oil pressure and if so rip the motor out,remove the sump,check the bearings and I am sure all will be revealed,no oilpressure at all maybe the pump drive,Cheers Trev.

 

I had a rattling EFE valve....it's in the exhaust pipe close to the engine...maybe on the passenger side!!??

 

Whats an EFE valve? And no this was like no rattling or clanging or leaking exhaust i have ever heard, this was internal, and this was baaad. The new block is here though, going in saturday.

 

Early Fuel Evaporation. On carb (and TBI, I think) wet-flow systems. Closes off one side of the engine and forces exhaust through the cross-over passages of the heads and intake, warming up the floor of the plenum, keeping fuel from pooling before the engine warms up.

 

did you put valve covers on upside down ,or on wrong side? lol i did, they are tapperd a little on one side and lifters wore holes into covers from hittin. im not motor expert obviously but hey it happens lmao

 

Yeah not EFE, this used to be a TPI car and just has straight headers.

 

Well gentleman I found the problem. Anyone want to take a stab as to what I found lying in my oil pan when I pulled it off? It was my oil pump pickup tube that had somehow wiggled its way loose, fell off, and wreaked havoc upon the lower end of my motor. The piece itself looks fine, but there are knicks all on the crank and rods. Seems it got thrown around quite a bit. I haven't the slightest clue how it could have fallen off though. Man, there was so much metal in the oil pan too, it took a ton of carb cleaner to get the inside looking new again. As of now, the new motor is in and mounted to the mounts and tranny, accessories need to be put on, rockers lashed, distributor installed, and radiator put in. After that she should fire up!

 

hahaha, ouch!
Are you taking the goodies off this engine (the roller cam, 200cc heads) and putting them on your "new" engine?
Did the lack of oil kill the lower end bearings? If it didn't, then the bottom end is probably fine. The pickup could be tossed around a lot, but the journals are pretty protected, the counter weights are pretty strong, I wouldn't guess they'd be harmed by a little stamped metal oil pickup being tossed around...