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Old 01-27-2018, 10:51 PM   #82
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Location: LB, Germany
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Originally Posted by 911monty View Post
I'm just going to throw this out there as something to consider. I can tell by what you've already accomplished that you have no reservations to getting your hands dirty.
I question how "oily" the cats can be. Let's think about the sequence of events and how oil came to be in the cats in the first place.
Flood waters rise and enter the muffler. water fills the entire exhaust system and enters a couple cylinders, (intake valves are at top), then displaces oil to the TOP of the crankcase and back out through the cylinders. Because the exhaust system is entirely full and due to phase separation (oil floating on top of the water) then the only contact of oil to the cats is at the top of the substrate as the oil migrates out the exhaust in a thin stream at the surface of the water. What does this mean? It is likely there was only a minor stream of oil in the exhaust at any given time, far less than the flood that would be seen from a failed AOS that experienced hydrolock. The water/oil did not form an emulsion since it was never sheared. Certainly cleaning is not going to hurt anything but is it necessary?
Regardless I am enjoying this thread. Keep up the good work!

The point of this post is: in my experience with flooded boat engines is that the quicker you could get one running (usually hours) the better. Detailing can happen later.
I think you've made some good points here. Let's think about in detail. What options do we have when the car was flooded and what damage can be caused. I try to keep it short.

Engine casing: alloy. Pistons: steel. Oil control rings: steel (can rust). Piston rings: steel (can rust). In general some carbon resedue, because it's a used engine. Catalytic converter housing: stainless steel. Catalytic converter: ceramics, and materials that start the redox reaction above around 500° C / 932° F.

Car did sit für 4 months and was flodded with sweet water. Sweet water is a plus, because salt water would have been much more agressive. But the not stainless steel / not alloy parts can be corroded a bit. Will it make a difference if it sits 2 days or 4 months? I would say yes. Will it make a difference if it sits 4 months and 2 weeks. I would say no. Also the conditions in which it sat might make a difference.

Was the water conatminated with sand or debree? If yes that seems intake wise to be stopped by the air intake filter. In that case Exhaust wise sand / debree can have found it's way into the combustion chamber. Water could also pass oil control rings and piston ring gaps and get into engine housing. Very small debree might sit in between them or passed. That would be a minus, because of the alloy block. (I suspect in sweet water rivers / lakes you have cleaner water (OK maybe not in harbors)). Will water have solved the carbon inside the combustion chamber in 4 weeks? Probably not.

Parameters we / i don't know:
Was the engine running and hot, when the poor car was flooded. Was the engine stopped by flooded water coming in the intake system. And would that make a difference?

How was the car saved? For example: if the front was lifted while saving it initially, this would be a plus, because fluids could run out of the exhaust system. But we don't know that.

Oily cats and what kind of oil/water consistency might we find there:
If the engine was flooded while running i suspect the redox reaction in the cats was stopped before the oil was flushed into them. So i suspect they were "cold".
Could there be an oil/water mixture caused while the engine running? Hm, to me that seems to be improbable.
Could be oil / water be sucked back into the engine if the header / exhaust systen is connected to the engine while starting for the first time? I would say no, but Honestly not shure about that. If the car was raised in the front, most of the liquid will be come out of the exhaust system. And because 78F350 said the muffler is off the car now i would say fluids have had their change to drain away the exhaust system.

So i think 911monty is right on that. Kind of hydrolocking will be not possible. Headers don't need to be removed, but i think it's a good idea to remove the muffler and lift the front of the car before starting it.

Grand childen:
Seems to have a very good influence. Videos have sound tracks now.

All fingers crossed!

Regards, Markus
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