sheape

So heres the back ground info, I have a 2008 Cobalt Sport with an LE5 motor. I supercharged it last january (went one year before issue's) and to be clear the S/C did not cause this. So i started my car to warm it up before i went to work. Leaving my house when i got the car around the corner from my house the serpentine belt shredded a rib and i hadent had this problem sense i first S/c. I got it back to my friends house (just down the road 1000ft) the car stopped running right as i got to the house. In the hellish winter weather we have in (Bend Oregon) i went out in -10 weather and changed the belt around and then the battery was dead. after 30min of trying to jump nothing. so i got it towed to my house(Friend tows cars for a living thank god) and in my garage. going out in my drive way a few days later i see rainbow colors in the melting snow. Where did that come from? well i went and looked at my oil pan and sure enough there is a big hole in the pan... My timing chain hasn't been changed sense i got the car at 84,000 miles its currently at 136,000 miles. something inside the motor is fucked . So i will have more updates to come on what i find wrong. my question is what should i do? Get another LE5 motor or would it be better to rebuild? if a rebuild is the best idea is there a forum post that can walk me through the rebuild? All help is appreciated and i will post pics through out the rebuild. looking to just put forged internals in it so i can have a 400hp balt. Let me know what you think and would love to have the support of our community

exninja

iTrader: (1)

You should figure out what happened before you know what the next step is. Obviously you can't rebuild if the block is hosed.

tomj77

iTrader: (2)

Hole in the oil pan, perhaps there is a rod laying somewhere down the street. How do u know it want the supercharger. Putting more stress on parts that were not originally meant to see boost could have weakened them over the year, then maybe a rod just gave up. Just my idea, not saying that's it, but u never know. Put an lnf in it lol

Spawne32

iTrader: (1)

The 08 LE5's dont have forged rods from the factory, so this doesnt surprise me in the least.

sheape

I went a whole year without issue was boosting at 6lbs of boost?

Spawne32

iTrader: (1)

ticking time bomb, also how was your car tuned?

umrdyldo

iTrader: (1)

Your supercharger was the cause of failure. Too much power for the rods most likely.

I assume you knew that higher power equals broken engine/trans at some point. Sorry it was only 1 year..

Slowbalt2000

iTrader: (1)

Op were you boosting at all before it broke?

I dont think a rod would just break due to previous stresses. Ive been beating the **** out of my l61 on stock rods and my engine is fine. Possibly you hit something in the street, drained the oil and seized it up?

sheape

boosting 6 lbs, never had a problem with the car until now. I started it up before work and let it warm up for 15min then drove down the icy street not doing a pull or putting stress on the motor. I have taken off the fuel rail and the valves in there look fine so i'm assuming it was an exhaust valve maybe.

Spawne32

iTrader: (1)

Was the car tuned?

sheape

Yes ZZP standard tune

nhanson

iTrader: (1)

You remember hitting anything?

How do you know the motor is bad? Maybe you can just replace the oil pan and be ok

sheape

no, So i removed my S/c and looked at the intake valves and they all look fine. I then removed the valve cover and all the springs look good and timing chain is in place but motor is still seized. when i looked into the spark plug holes at the cylinders and pistons they all look fine except piston one it looks to have a hole in the center. but i can't tell until i pull the head off. My problem is i have never taken a head off a cobalt.. can i leave the cams in and remove the timing chain and the studs in the head and remove it? is there a form post someone could link me to for this part of the take down?

05g5

Remove the cams and sll the rollers and rods. Keep them very neat and organized incasr you put it back together. It's important everything goes where it was ( unless you go new )

Reason being is the head will have to be machined and tested.
Again this is only if you plan on re-using it, might be easier to drop a new motor in it when you see te damage to the block.

Oh and it's easy to take these heads off . Loosen the cams, take the timing chain tension out and slip the chain off. Buy a 6 pack and before you finish 2-3 beer it's out.

sheape

Hey guy i have an update for you all, Today i finally had time to remove the head. the pistons look okay lots of miles on them lol all my valves were there but when i manually tried turning the engine it didnt move one bit.. what could that mean?

Spawne32

iTrader: (1)

means your bottom end is destroyed lol gonna have to pull it the rest of the way and take the oil pan off and see whats going on.

nhanson

iTrader: (1)

Kind of odd that there werent any loud noises if the bottom end was destroyed.

The car just shut off without any bad noises?

Spawne32

iTrader: (1)

what do you think the hole in the oil pan signifies?

Slowbalt2000

iTrader: (1)

Im betting its seized. Probably spun a bearing

chris88z24

Lol, the supercharger definitely contributed to this. If you think it didn't then you're either ignorant or a moron.