have ls1 Xr275hr cam. Full exhaust.
I have a weird lifter tick noise but it isn't constant ticking. More intermittent metal on metal tick or a clack. Not a deep noise or knock. Has stock heads. Springs are good for the lift but have about 15k miles. Hardened 7.4 pushrods. Anyone had this before? It's a ticking that I can only hear at idle. It's not piston slap more of a clacking like a messed up rocker or something. The thing that stumps me is the intermittence that makes it very hard to pinpoint. I'm at work but on next day off will be pulling valve covers to inspect. Just wondering anyone's thoughts on this beforehand.

 

Hard to say without much info. What are the full specs of the engine? Can you determine if it's coming from the top of bottom or the motor, driver or passenger side? Can you get a video of the noise? Take off the valve covers and make sure it is not a rocker arm loose

 

The thing is it's not a consistent clicking so it's kind of hard to pinpoint. I will be able to get the valve covers off Wednesday and see what's going on. Its weird cause the clack sounds horrid but it doesn't do it when revved or anything just very low rpms idling and coasting around town
ls1 rebuilt 20,xxx miles ago from crank up. Xr275hr on stock heads, all new valvetrain full exhaust

 

forgot to note that on cold starts there is no knock or clack just the typical ls piston slap. It does sound like from the top of motor

 

Here's a link to video of car after its hot.

 

Idler pulley failing...

 

I have no idea. It's the only thing I miss about my old lt1 these aluminum blocks echo the sound through everything and kind of hard to pinpoint. It's smooth and quiet until up to full running temperature.

 

Get it up to operating temp. then take the belt off and let it run long enough to see if the noise goes away...

 

X3 on the idler pulley failing. like cookseyb said take the belt off and let it idle for a few bet you don't hear it. good luck and let us know the outcome.

 

I'm off tomorrow so I will be sure to try that. Hopefully that's the issue. If that doesn't solve it I've got a sneaking suspicion about a rocker that I boogered up a little on a money shift a long time ago. I'll post back tomorrow or Thursday with results

 

no deal on drive belts. So I drained oil. Luckily magnetic drain plug. Found 2 needle bearings stuck to it. Taking off valve covers now. Pulled both valve covers. All rockers had the caps on them. Can needle bearings still spill out somehow??

 

If they are stock, high mileage, and you pushed them beyond their limits: yes.

Time to pull them all and call Straub. Make sure you are careful during the removal.

 

Those look too big for a rocker prolly from a lifter...

 

wait so these aren't rocker bearings? Oh jeeze. This simple fix became seriously a pita

 

For reference here are a couple stock rocker needle bearings.

 

oh my. I've never had the heads off this car before. Is my cam trashed from this? If so. I think I'll go bigger when I scrape up the funds for a proper cam swap. Right now it's 222/224 at something around .568 lift...anyway How much time and $$$ am I looking at for just the lifter swap.. new trays and lifters. Head and header gaskets. New head bolts. Is ls1 special that I'm missing something? Any recommendations for parts? Right now at the moment is car relatively safe to drive? I need to get it out of my garage and back home

 

I am far from a expert but imo I would tow it home.

Also imo the worst part about pulling heads is getting the stock graphite gasket clean off the block deck..... Miserable!

Pulling the heads tho is not bad and straight forward. If the heads have been off before it should not be to bad cleaning wise.

Lifters $150
Trays $20 for all 4
Gaskets $75 - $150

 

looking at this kit. Good package deal?
http://www.ws6project.com/user_stor/...oducts_id=7659