kricket

I just recently bought a 2007 Z06 with an engine that was overfilled with oil. I bought it for a price that would easily cover a new engine and more but was curious after reading some survivor stories if there are things I could do to see if there is actual damage. I've taken the right hand valve cover off to see if there are any parts from the cap being twisted off. Is there just a bump on the fill hole and a little plastic tension lever on the cap that pops over the bump on the fill hole? If so everything looks intact. Just want to make sure there isn't anything else inside my valve train? I couldn't see anything. I do notice some coolant leaking past the oil filter but can't exactly see where its coming from. My plan was to buy a built motor and put it in but if I were to get lucky I'd keep this one in for a while. Any help on steps to take would be greatly appreciated! Thanks

Vito.A

How overfilled?
Was it started and if so how long was it run?


These engines are very expensive and it's certainly worth some labor to determine if it is serviceable.


First drain the excess oil.
Remove the throttle body and look into the intake manifold for oil. If excessive, pull the intake manifold and then check the cylinders.
If not excessive pull all the spark plugs and turn the motor over. See if excessive oil comes out of any of the plug holes. If excessive then pull the heads and check each cylinder/piston.

If removing the heads is not needed, next perform a leakdown check on each cylinder and record the results.


Extra: While you have the valve covers off I'd perform a wiggle test on the valves. GM no longer recognizes this test but it can tell you if the guide clearance is grossly excessive and is a good chance to check each rocker, valve stem seal, pushrod, and retainers.


If it still has an oil filter installed I would cut it open and check the folds for metal.


Once everything looks/checks good, install the proper amount of oil and filter and start it.


Best of luck!

kricket

Sounds like there was about 14 qts in it. I was told it was only driven about 40-50 ft before loss of power. Just easing out of the oil change bay. I'll go through the steps and let you know what I find. Thanks for the help! Any idea where the coolant may be coming from?

50 4Ever

Sounds to me like the engine could of hydrolocked, if it was indeed 6 quarts over.

Good luck...

stefuel

Ever wonder why in the thousands of commercial flights that fly overhead daily don't have more service related problems?

crAzy

Friend of mine who bought one a while back overfilled his by accident. He read the dipstick wrong thinking the 3 dots meant qrts instead of low, half filled and full. So he added about 3-4 qrts more than the 8 it took. He was able to drive it around the block until it cut off on him. Luckily it died on him while he pulled into his driveway. He said it wouldn't start nor turn over. So I came by and he told me the story. So I told him to pull all the spark plugs and remove the coil packs. Once the plugs were out i told him to turn the motor over until I say stop. Once he turned the motor over oil came out of a few cylinders. We kept doing that till no oil came out. Also we removed the intake as it was flooded and so was his air filter of oil lol.

Long story short got new plugs, drained engine oil/refilled, put it back together and it started just fine. Of course there was a lot of smoke. This was about 4 months ago. Car running great to this day.

Dan_the_C5_Man

with this.. So long as the motor wasn't spinning at high RPM's (it wasn't), it is possible it choked on the oil from the intake and caused it to stall before it ingested enough to hydrolock.. The OP can hope that is the case anyway.

I would have recommended the above, with the exception that I would not turn it over with the starter - you can break the mounting tabs off the block that way - I would turn it over by hand.

crAzy

I would think there would be less stress on the starter since the sparkplugs are removed? But yea that is another way of doing it. Longer way of course, but with much less risk like you said.