Mazen123

2006 corvette c6 z51 with 28,000 miles. Recent Cam, spring, pushrod install. Louder than normal valvetrain noise after install, car still ran good rhough. Dyno tuned and made 465 at the wheels. Drive it home, put on 50 miles more then boom, Tapping noise occurs from the valvetrain area , I freak out (I was driving on a busy road) tapping noise gets louder and louder. No oil warning light or codes thus far. Boom something I hear snaps or breaks, oil pressure drops to zero and car shuts off and coasts. I pull over, car refuses to start. (Only tried once for a sec). I get it towed, I open up the covers. Springs fine, push rods fine, I did have excessively play with one rocker. I checked the oil dipstick and the oil in the cover multiple times, no metal flakes at all.

Pulled the codes, p0340
Camshaft position sensor

What could this all mean? Lifter collapsed? Fail Cam? If so am I OK without seeing metal shavings it those places (concerning the engine)

What do you guys think?

Mazen123

Also had an underdrive pully installed to replace a wobbling balancer. Could this be a broken timing chain maybe?

extrapilot

Something failed in the front of the engine with that trouble code. Tapping lifter noise should not happen after a cam install, and could be a cause of a lot of things.
There had been some posts here about camshaft bolts backing out, but why the no oil pressure is not good. Perhaps the cam thrust plate is damaged as well, as it's used also to close off the front oil passage ways to the lifters. Or the timing chain or sprocket damaged the crankshaft drive to the oil pump.
Sounds like a front end tear down at a minimum is needed.
As far as the oil having metal particles in it, I would say have the oil filter cut open and investigate what the pleats look like inside the element.

tennblkc6

rut roh...hope it's nothing more than lifter and cam damage.

z06scentair

Was loctite applied to the cam gear bolts?

That's what it sound like to me......those bolts are notorious for backing out.

Mazen123

No, but they were torqued to spec with a digital torque wrench. Man that's crazy, I will start tearing it down today

extrapilot

I would also advise to check the condition of the lifter trays, as they have been known to crack and allow the lifter to twist around in the bore, negating the rollers to work as they should and scar the contact points.

need-for-speed

Good luck and let us know how it turns out.

Mazen123

I drained all of the oil and took apart most of the engine today. I didn't find any metal in the oil drained. Is that good enough to confirm that there is no metal at all? Or does the filter have to be cut. What's a good way to cut the filter?

extrapilot

There is a tool made for cutting oil filters apart without creating metal fragments.
A alternative would be using sharp sheet metal shears.
You should know that the oil pump will pass the oil first to the filter, so if anything is in the oil, metal should show up there first. It's also possible that the engine died before it had a chance to pickup any contaminated oil.

What have you seen damaged so far?

CadVette

Not sure how far you have the engine torn down yet. I agree you should inspect the camshaft bolts and timing chain. Excessive play in one rocker could be a big clue. I pull the camshaft and inspect it. As for that one rocker that's loose check the cam lobe in that spot. Also the lifters and the trays as mentioned by extrapilot. Take the pushrods and roll them on a piece of glass to see if it is bent. A visual inspection does not cut it. If you heard something snap or break, you should be able to isolate the problem. Hope it does not cost you too much.

Boilerman

Could be the oil pump shaft busted, that happened to a friend's pump on a new engine.

Rjhctrapp

Oil pump on these engines are driven by the crank. No pump drive shaft like the old engines. Oil pump actually slips on to the end of the crank snout and sits behind the timing cover.

Landru

Good enough next step's engine tear down one layer at a time 'til issue reveals itself, IMO. Nothing else left to do, at this point.

G/L, hope it's only interesting learning WTH happened w/ min $ loss.

sevinn

You can use snips to open the oil filter:



Sounds like cam bolts backed out to me. You said you torqued them to spec...were they new gm bolts or arp bolts?

extrapilot

SEVINN
Nice find (video), this should make it easy enough..

sevinn

I would recommend wearing cut resistant gloves...ask me how I know lol

need-for-speed

I bet ! Ouch.

Orion2011

I don't want to come off negative because you may be an ace mechanic and know what you are hearing. If so forgive me for my post. How much of a noise are we talking about? I have seen people run their car up to the dealer for service because they just noticed the fuel injectors clicking for the first time. To a non mechanic it sounds like valve train noise. Hell I even did it once back when I was a noob.

extrapilot

I think the OP has a little more than a tapping noise now. The engine made a snap noise and shutdown with no oil pressure, according to his first post...