Any techs around that can tell me how to fix a valve tick coming from cylinder 1 on a 3800 supercharged L67...

Any techs around that can tell me how to fix a valve tick coming from cylinder 1 on a 3800 supercharged L67. Just bought the car for peanuts because it needs a supercharger rebuild, but I was cleaning the engine and it developed the tick up top. Anyone ever dealt with this? Im taking the valve cover off tomorrow to look for obvious things.

Sure it's an upper end noise? I've had TWO L67's with spun rod bearings now. Fucking meme engines.

It seems too light to be a rod knock, plus it goes away and fades in intensity sometimes. Also i used a stethoscope and it sounds really loud on the valve cover. But all in all it seems too light for a rod and it doesnt change when I unplug the plug.

If it is a rod knock would changing the bearings with the engine in the car fix it?

Not without machine work. Unplugging the spark plug isn't going to do anything to help yor diagnosis. It's going to be impossible to diagnose a noise over the internet. First thing I would look at is the lifters.

Am going to tomorrow. Anything in particular i should look at?

It's not GMs fault people beat the shit out of a supercharged car for over a decade

Learn how to find a good car

Not really. First one the owner had glittered the engine.
Second one actually wasn't that bad but the crank was wiped.

You'll know right away if it's top end or bottom end. Don't these things have an issue with something in the M90 breaking and making noise? Sure it's not that?

I don't give a shit, not my cars. Just customer cars. I would never own one of these piles.

Is it a legit mechanical ticking or is it perhaps an exhaust leak?
Is it a knocking or ticking sound, OP?

If you say it comes and goes I might suspect a lifter. My lifters would 'tick' noticeably on engine decel. Replaced with CompCam OE lifters.

>Pic related is my L36 with a few simple mods

Are you sure that it isn't just the regular ol GM lifter tick? It should go away once it heats up.

The girl i bought it from ran the supercharger dry as far i can tell. I put oil in it and it spit it all out at the pulley this tick is far too fast and rhythmic. Im already looking for a new used m90, i dont think a rebuild could fix what dhe did to it.

Yup im sure I narrowed it down to cylinder 1 its a light tick you can barely hear with th hood closed.

Does it do it at all RPMS?
Hot & cold?

As far as I can tell. I havent pushed it at all since I first heard it.

But definitely up to 3k rpm. Hot or cold.

I guess first thing when you take off the valve cover is check if the rockers are sloppy. Check if the pushrods are bent.
I imagine your valve springs are find, else it would run like hell and would have probably chewed itself up already.
I'm leaning towards a lifter that's shit itself.

Is a rocker r&r a pretty straight foreward job if the LIM doesnt have to come of? I dont fuck with the timing or anything like that?

You can't reuse the OEM GM rocker bolts. They're a torque to yield one time use bolt.

Go to a GM dealership for new ones OR buy some ARP reusable ones (Which I did because I've torn my 3800 apart more than once)

Other than that replacing a rocker arm on a 3800 is easy as hell. Torque the bolt to the proper spec and that's it. If you have a loose rocker you might have valve, valve spring, pushrod or lifter damage.

Taking the LIM off isn't even that bad.
Use sandwich bags and a permanent marker; label ALL of your bolts and nuts so you know where they go back. Use a new aluminum LIM gasket, DO NOT USE THE VINYL PLASTIC ONES!!!!

Pickin it up for knowledge.

Outstanding

I have side play on a couple of the rockers but thats it. I dont know how to test at this stage.

A small amount of side to side is okay, excessive is bad.

At this point it's probably a lifter, or a bearing somewhere.

If you could get a video of it running making the noise that might help us out.