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-   -   Catastrophic AOS failure? (http://986forum.com/forums/showthread.php?t=60683)

ger986 03-05-2016 03:16 PM

Catastrophic AOS failure?
 
Changed oil, level is high

Thinking of removing some oil

Later while driving, crazy amounts of smoke suddenly appear.

I think, "AOS failure" and pull over immediately.

Car makes a clunk sound when I turn it off.

Towed it home. When there, it won't turn over. Decide to let it sit a few days.

Pulled the plugs and intake passages. Oil everywhere.

Engine turns over, but seems to do so slowly.

Tried turning over by hand. Can't do it.

I know what I think, but I was hoping to get some educated second (and third) opinions. Thanks.



Pic from better times:
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Smallblock454 03-05-2016 03:48 PM

Well, 99% shure, that is no AOS failure.

If the AOS itself is shot you wouldn't have any problems to start or crank the engine.

Regards, Markus

BYprodriver 03-05-2016 04:07 PM

If you overfill the oil it can get sucked thru the AOS & get into the cylinders.

Remove all the sparkplugs & try to start the engine. It won't start but any oil in the cylinders will be forced out. Trying to start the engine with oil in a cylinder can bend a rod or break the cylinder wall. Once you have forced all the oil out inspect the sparkplugs for damage or oil, reinstall good plugs & try to start. Be gentle & cautious as the engine may be damaged & it could get worse. The engine can run with a slightly bent rod but not for long! :eek:

ger986 03-05-2016 04:42 PM

You'll note in my synopsis that I did pull the spark plugs and turn over the engine with the starter...

If the AOS didn't fail, then how would so much oil get into the intake manifold, throttle body, and other intake passages?

Shouldn't I be able to turn it over by hand?

Steve Tinker 03-05-2016 06:40 PM

How much oil did you put in the engine when you replaced it? If you have hydrolocked a cylinder, you would have put a lot of "extra" oil in the sump...
The clunk you heard when you switched off the engine is not a good sign. Now the plugs are out, it will pay you to try to do a compression test, turning the engine on the starter motor. And yes, you should be able to turn the engine by hand without the plugs in place, but I suspect the damage has already been done, if it was caused either by overfilling or a blown AOS.

Gelbster 03-05-2016 07:25 PM

Steven is correct but as a diagnostic, try this,
drain all the oil
try to spin the engine with spark plugs out and fuel relay removed.
If you have not bent a rod ,it should spin easily. Don't do more than a few seconds to proove the point.
Refill with correct amount of oil and repeat.
You might consider checking the valve timing ?

jdraupp 03-05-2016 07:26 PM

Quote:

Originally Posted by ger986 (Post 486112)
You'll note in my synopsis that I did pull the spark plugs and turn over the engine with the starter...

If the AOS didn't fail, then how would so much oil get into the intake manifold, throttle body, and other intake passages?

Shouldn't I be able to turn it over by hand?

You caused the aos to fail by overfilling the oil. That oil has to go somewhere. Hydrolock is the term and the outlook is not good.


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