Busted Motor!

**Camaro Rick** · 08-25-2006, 02:30 PM

Went to the dragway the other night. Heard a noise from the valvetrain. To make a long story short, I was standing there with 2 Chevy mechanics and an LS1 guru... listening to a slight ticking noise from the driver's bank and periodic hesitation. Sounded like a cylinder misfire but only lasted a few seconds at a time. Then while it was idling, we heard a snap and the motor began to barely run. I shut it off(I also noticed no smoke coming out the back when I shut it down). We tried to start it up, but it wouldn't catch. What could it be? a pushrod? a spring? and rocker?

I just pulled the valve cover this morning and to my surprise, nothing is apparently broken. I turned the motor over by hand while a friend made sure each rocker moved. Everything seems to be fine. Next I plan on pulling the rockers off to check the pushrods ..But what could have honestly broken? I'm stumped.

my volvo technician brother said to pull the intake manifold and check under the valley cover..but what's under there that would give me any hint to the breakage?

I apologize for my first post on this forum being a negative one, but am searching for greatly needed advice. Thanks in advance.

Rick M.

**Sarge** · 08-25-2006, 03:37 PM

Well....Sounds like a rod bolt....or bolts....got metal in your oil?

**LS1Pwrd01SS** · 08-25-2006, 03:44 PM

My LS1 self-destructed about 3 weeks ago with only 58,000 on the odo. It was making a similar noise from the drivers side before it finally let go. But, mine still ran even after it broke. It sounded like crap and smoked, but it still ran. Turns out mine swallowed a valve, internals are scrap now. I hate it for ya man.

**Camaro Rick** · 08-25-2006, 04:17 PM

Rod bolt?

I haven't drained the oil but I did take a look at the oil on the dipstick. Don't know how much of help that is, but it looked clean. I'll probably drain it tomorrow and check. I also plan on pulling the intake manifold so I can take a better look at the valves.

My motor still ran...before I shut it down. I want to say around 200 rpm but I didn't really see. I didn't hold it for too long when trying to restart it. It didn't sound very good. I'm wondering.. If it's nothing I can see... Why couldn't I just attempt to remove the head? I don't want to spend that much but is it possible I may have to buy all new internals and heads?

Rick M.

**02z28ls1** · 08-25-2006, 06:56 PM

Before you go any further -do a compression test-do a leak down test-pull plugs and look at them closely for anything out of the ordinary. Try to diagnose it further before taking anything else apart. Maybe it set some DTC's in the computer? Spend some time diagnosing the problem. If all your valves are moving properly what are you going to see under the intake manifold? Do you still have good oil pressure?

**Camaro Rick** · 08-26-2006, 04:52 PM

I checked the spark plugs. No sign of irregularity.

Pulled the intake manifold and peaked around with a boroscope. No visible damage, atleast to the intake valve. We also just ran a compression test on the driver's bank. Numbers were all between 190-160. Apparently this is normal on a cold motor. No abnormal noises coming from the motor while cranking.

All these clue's are leaving me stumped. It couldn't be a lifter because then I wouldn't have any compression, right? Or what if it was a lifter for an exhaust valve. But, What could that sound have been that I heard right before meltdown? The four of us heard a SNAP then the motor ran like junk. Other sugguestions state that A coil can make a sound similar when giving out. But what could explain the ticking noise I heard right before the motor gave up? It sounded like the regular "lifter tick" or "piston slap" but way more audible.

Rick.

**0rion** · 08-26-2006, 08:47 PM

Your positive you didn't break a valve spring then?

**Redphoenix1998** · 08-27-2006, 12:48 AM

you didn't drain the oil or anything? There's a magnet at the end of the plug, if you broke something, it'll pick up the metal frags for sure. Possibility you could've also cracked a rod or spun a bearing. It could be a number of things. Ticking could also be an injector stuck, so check those out as well

**Camaro Rick** · 08-31-2006, 08:18 AM

Well. I'm about to check my oil... I've summoned the knowledge of several trained mechanics and it seems they all completely rule out the spun bearing. Also, a coil may have caused the initial sputtering but caused a metallic snap and the motor to quit? I can't imagine the injectors being as loud as the tick I heard. It was the lifter noise you get on cold start up. but way worse. But could it be my lifters if all my rockers move and the cylinders still have good compression?

Next step after checking oil is to check the lift on all of my rockers while hand cranking the motor...

Anyone have valve lift specs on a 2000 LS1? I don't believe I'll need a micrometer but possibly something I can measure in milimeters? Thanks.

Rick.

**nosfed** · 08-31-2006, 08:32 AM

Originally Posted by Camaro Rick

Well. I'm about to check my oil... I've summoned the knowledge of several trained mechanics and it seems they all completely rule out the spun bearing. Also, a coil may have caused the initial sputtering but caused a metallic snap and the motor to quit? I can't imagine the injectors being as loud as the tick I heard. It was the lifter noise you get on cold start up. but way worse. But could it be my lifters if all my rockers move and the cylinders still have good compression?

Next step after checking oil is to check the lift on all of my rockers while hand cranking the motor...

Anyone have valve lift specs on a 2000 LS1? I don't believe I'll need a micrometer but possibly something I can measure in milimeters? Thanks.

Rick.

Did you check your lifters? I had very similar signs and I ended up busting up a lifter. It went down and scared up the block, tore into the crank and took out my crank sensor which was the code it through. Just ideas, may not be anything close.

**Camaro Rick** · 08-31-2006, 11:34 AM

Whoa. Scary. Well. I wouldn't be surprised. I just want to make sure as hell it's a lifter problem before I pull the heads and buy new lifters. I just don't think a lifter fell out...because my valvetrain all operates normally. you know? So it could be a less serious problem with 1 or more lifters that is barely showing it's face...causing the motor not to run apparently. I hope it's nothing like internal scoring or anything fun like that... Thanks for your responses guys!

Rick.