Loss of oil pressure....
 

About a month ago, I changed plugs and was greeted with this noise at cold start. Found I'd left a plug wire off on the passenger bank and thought it was the sound of the wire arcing at first, and it went away after a few seconds of running. It only happened 2 or 3 subsequent cold starts and stopped happening. Video is of the last time.

https://photos.app.goo.gl/rMNajkRJ7oW3KFCf8

Christmas day I lost oil pressure while cruising from 40 psi to 22-25 at 2k, 18-22psi hot, only to have it restored with an oil/filter change. Filter had a couple SMALL chunks of metal, no flakes, all magnetic. Drain didn't look like a unicorn stripper glitter soiree. Was fine for about 1000 miles. Oil pressure dropped again, pulled the filter, found more metal fuzz on my magnet when I sweeped the filter pleats, but nothing major. Same symptoms as before- oil pressure gradually dropped while driving down the interstate, about 300 miles post oil/filter change. No changes in power, no funny pops, nothing. Until the last time- valvetrain noise at startup for about 3 seconds, and even after changing filter/oil, valvetrain noise when I rev it up, and it goes away on engine decel.

Pulled valve covers and found squishy lifters on the driver's side.

Pretty sure
1. the lifters (Summit HT217/Morel 7717) are bad or got slightly cocked in the brand new GM trays,
2. chewing up the cam
3. causing the metal debris
4. in turn clogging the filter and
5. causing the loss in oil pressure over time.

We're pulling the motor out to inspect and repair. With my limited driveway capabilities until we pull, does that sound like a plausible diagnosis? Having access to a heated shop and lift is making me feel too old to keep doing this in the cold on a driveway with a 25* incline.

Thoughts, ideas on my diagnosis?

That doesn't sound like rod knock. So that's very possible.

That clanking sounds random.

Can you hook up a mechanical guage to check for fuel pressure? My experience is the guage cluster reads lower than the guage pressure. At least on my 99 it did.

But the metal in the filter is a bad sign, no matter what the pressure is.

It's definitely not rod knock. Didn't make any noise until yesterday. Valve train only.

That's what I thought too, and it was coincidentally only happening every morning after I washed my truck during a cold snap - highs of 25 or less.

We may hook up a mechanical oil gauge but discussed just pulling the motor because it takes about an hour and we can inspect bearings and cam from the bottom side to formulate a plan and order parts.

I think that's a good plan. It's weird that pressure was restored if the only thing in the filter was a few chunks of metal, wouldn't you say?

I think the fact that it's NOT knocking is still good news. Hopefully the rods/mains are still "ok," that maybe all you need is a polishing or just new bearings.

Let us know what you find. 🤞

Did you buy the lifter kit with trays from summit?

How were the trays packaged?

Trays were from Rock Auto- GM genuine, packaged in GM packaging.

GM Genuine in GM packaged trays, cam bolt, knock sensors, VVT Sprocket, Solenoid, etc
All gaskets are Fel Pro.
Clevite P series bearings.
Melling M365395S Pump/tube assembly.
Cloyes timing set (single/OE replacement).
Comp Cam
Summit/Morel HT217-16 lifters
BTR 7.4 hardened pushrods
Pac Springs

Even GM was having issues I believe.

Yeah, the reason I asked is because some companies are advertising that they are GM Parts when in fact they are not. They always come in generic packaging.
I recently assembled a motor that had some trays from Texas speed. I could see they were different and had different markings. Needless to say, they went in the trash can...

Issues with lifters or lifter trays?

I know Summit, Rock Auto, local parts stores are safe to order GM parts from, but if they're having issues, what brands are "equivalent or better" on something simple yet crucial like trays.

That's frustrating...cheaping out the cheapest part. I've been snooping around 'boutique' suppliers like Texas Speed, Michigan Motorworks, LSXeleration. I've often assumed the more economical parts or packages are a lot of the same knockoff (chinese) parts under different labels. For the money we spend on cam/lifter kits, you'd think they could at least throw in quality OEM trays. Not like we're expecting linked lifters at the prices the packages go for. I do expect more than 1 sticker though.