took a stethoscope to the front housing, didn't sound like anything, however when on the water pump housing it is very prominent and loud. haven't replaced the pump yet since I'm still replacing a few things to get it running again, but I was told this could definitely be the water pump. after a little research I'm not sure if this is the case since I've never had a cooling issue or an overheat. Will a water pump knock? or is this an internal bearing issue and I'm way over my head haha

 

haven't had much time to work on it, it's been pretty cold and I only have one light to work with at night and limited on tools. Just replaced injectors and alternator, new battery is next but once I got it running it sounds half assed like maybe the plugs suck but they were replaced before the car was taken off the road. I'm gonna replace them and the wires, but as I said I'm more concerned with the mysterious noise. it shut off after cold start and then idling by itself.

 

Spun bearing will make a knock. I had a spun bearing for a week before i had serious problems. If its a Tapping could be the oil pump chain? Or heat sheild,

 

could be the main pulley coming loose from the boss or the boss from the e shaft
now it could be the water pump, I've seen pulleys make strange noises but i would probably pull all the belts and run it for a moment to see if it makes any difference. Don't let it run too long, you wont have a water pump.

 

I had the noise for a while and was able to drive with it which was strange to me, kinda figured it was on its way out but after a month of nothing but noise and nothing catastrophic I was a little lost lol. all the belts seem pretty good, didn't think of a pulley though. but the noise is very noticeable. I really hope I don't have to dig into the block -___-

 

oil pump chain is possible though, my oil pressure has been low for a while and I was thinking about checking out. if it's a bearing I dunno what I'm gonna do cause I'm sure that's not a cheap fix

 

if it does happen to be a spun bearing, is it something I can fix myself or am I looking at an expensive pain in my ***

 

i had the same problem which sounded like a bad rodknock with my old engine that was rebuild by somebody which they forgot to put the spacer in the front cover on the of the trust bearing and it crew up the whole bearing and the shaft

You need to take the engine a part to see if thats the case in my case when i rev the motor i see the crank was moving in and out about couple of mm

 

Before you dig into the engine check the flywheel and make sure it is tight . I just took a spare engine of mine apart to rebuild and the flywheel was loose ( the nut was finger tight ) It would definitely make a prominent noise and it would be off and on as the clutch etc. was used .. Just a thought that won't cost anything to check . Gerald m.

 

Drain the oil and see what is in it, check the plug as well. If it is a spun bearing, you should see lots of signs of it in the oil (if it has spun enough to knock). I had a spun bearing, and sounded like a knock. Every time you revved it up, it would knock. It took me a while to figure out what it was. Also, I would think that the compression should be lower if you spin a rotor bearing. The rotor can move around more on the eshaft, allowing compression by on the rotor?