My car sits most of the week, when the weekend comes and i start it up it seems to have a small knock sound to it on the first startup,....


Should i switch my oil weight?

Is this normal on thisthe lt1 motor ?
It isnt bad or realy loud but i just notice it....

 

I've heard of engines getting piston slap when cold, but it seems to be more common with LS1's. What is your oil pressure at?

 

Could have been a lifter that was bled down, if it went away after a few seconds and only does it after sitting for a while I wouldn't worry about it.

 

Mine does it to. It did it bad when I changed my oil and used Castrol GTX 10w40 and then I switched to Castrol Syntec 5w30 and it quieted it down alot. Mine does it for about 30 seconds and stops. I think its just a little lifter tapping while they are filling back up after sitting all night.

My oil pressure is 60 on startup and when warm its 20 idling and 40 cruising.

 

Im running 10-30 I htink, I should try the 5-30.....

 

I may get flamed for this, but the lucas oil additive is supposed to prevent dry startups, you may want to add a half quart next time you change your oil. Just make sure you use the synthetic kind if you use synthetic oil. I wouldnt use a full quart though because it is so thick.

 

I'm not going to "flame" you for the lucas comment (i use it shhh lol) but dry startups are little different than a lifter that is bleeding down and tapping on start up. IMO the lucas would just make it worse being its thicker and switching to a 5w oil would work better.

 

Is it a tick or knock? Because if it isnt a piston clearence issue. It more then likely is a rod bearing issue

 

Normally I'd agree, but if its only during the first few seconds I don't think it would be a bearing issue b/c the would get worse when the oil heats up/thins out.

If it keeps doing it/gets worse might not be a bad idea to replace the lifters too.

 

it only does it the first few seconds ( maybe 20 30 seconds??) ,if it sits for a few days .

Other then that if I run it a coupke days in a row it seems good.

 

defently not a bearing... A bearing would tick more with the rpms going up

 

well the valvetrain parts move faster than the bottom end so we need figure out what your hearing.

valvetrain noise= tick.tick.tick....

bottom end noise= knock....knock....knock

when you lisien to the noise try to match it to my half *** description. a valvetrain noise will sound faster and more erratic than a bottom end knock. Since the valvetrain moves up and down faster than the rotating asembly rotates.

 

You are correct, but if it happens when the car sits for days, would it be a dry start issue or lifter?

I have a question, if my lifters are ticking in the morning will new ones fix the problem or is it because the clearences are getting bigger with the engine wearing down. 128xxx miles on it. Reason I ask is Im contemplating a cam change, which will come with a completely new valvetrain, and dont want to do it and my engine blow in 2k miles.