engine knock

**blackonblackz28** · 07-25-2006, 09:11 AM

I have an 01 Z28 and just recently out of nowhere started to experience a knock in the engine. I have pulled all of the push rods and none are bent. It sounds like it is coming from the lower part of the engine...I thought maybe I had spun a bearing but a couple of people have told me that it could just be my oil pump...is this possible???...has anyone else had a similar type problem??? Any info. would be greatly appreciated

**ram air ws6** · 07-25-2006, 09:24 AM

Hey, i have a 2002 WS6 and i have the same problem. I know quite a few other people who have cars like ours with the same problem. I thought it was the fuel pump at first so i changed it and still knocks. I don't think its something to really worry about as i was told that some of the LS1 cars do this. Not sure why but i wouldnt worry about it. Danny

**2k1ws6** · 07-25-2006, 10:33 AM

My car's been doing that ever since a bought it back 40k miles ago, never really had a problem though. It does get annoying so i've had it checked several times but it still does it. I too have heard of others who have had the same problem and it seems as if it is not a big deal.

**blackonblackz28** · 07-25-2006, 11:34 AM

Also though I have no oil pressure anymore...when I first started having the problem i had got down to the push rods and now after putting everything back together i have no oil pressure...could I have just missed a sensor??? or is it probably a bigger problem??

**0rion** · 07-25-2006, 12:40 PM

Did you have pressure before the tear down? The oil pressure sensor is on the back of the block directly behind the intake on the drivers side. Any chance you broke it off ( very common) or didn't plug it in? When I broke mine off my gauge light came on.
I think some people are talking about piston slap which is normal for most LS1's. It really sounds to me like you have a spun bearing though. Hopefully the no oil pressure is your sensor and you're describing piston slap but if you in fact have no oil pressure and are getting a knock my money is on a spun bearing.

The Rookie · 07-25-2006, 12:52 PM

Piston Slap is very common in the LS1 cars. Some people have even reported theirs sounding like a diesel. Mine does it at start up. Once it is warm it goes away. I was told the aluminum has to heat up which then tightens up the tolerances. They were built that way.

If you have a knock instead of a loud tapping noise and you have lost oil pressure(Your sensor is hooked up) then you have a problem my friend. Best way to look at it if that is the case, you get to rebuild it with all new, better parts!!! Make it strong!

**blackonblackz28** · 07-25-2006, 01:19 PM

I did have oil pressure before the teardown and it is very possible that I missed a sensor...but I dont know whether or not it is piston slap, it is kind of a high pitched loud tapping sound though...so the oil pump thing is probably not it then huh???

The Rookie · 07-25-2006, 01:23 PM

How loud is loud? Also, as stated above.. Make sure you do have the oil pressure sensor hooked up. I could be wrong, but I doubt it is the oil pump. How many miles are on the car?

**blackonblackz28** · 07-25-2006, 01:46 PM

there is 91k on the car and the noise is not too loud until you open the hood then it is pretty distinct but inside the car it is just kind of annoying