what happens when the engine runs out of oil?
 

How durable are these things? When the engine runs down to about a quart left and there's a knocking once it gets up to temperature, what should I be looking at? This is a 606NA.

Crank and cam bearing surfaces.

Nothing good happens.

I'm kind of thinking you should be looking at making a coffee table

http://inhabitat.com/springgreening/...20(3).jpg?zc=1

I'd be looking for a way to forgive myself for killing the engine. I know i'd be really angry with myself.
You could drain what's left fill it up with fresh oil and see what happens but good chances are the engine is FUBAR.

They aren't any more durable than anything else when it comes to being starved of oil. I'd really advise you to stop running that engine before you cause any more serious damage. I'd imagine all the bearing's are absolutely roasted....



If it really is only knocking when it warms up, if you're feeling adventurous, drop the oil pan and replace the bearings. I've done it on an OM603 that we have in small Mazda farm pickup - damn engine has been running for about 2 years now. Runs a lot quieter than my 300SD and 350SDL 603's lmao
Or sell me the car and I'll do it. :)

x2.

The cam bearings probably are OK as there is enough residue oil to lubricate them. The rod bearings are goner for sure. The main crank bearings may also be OK. My OM603 oil chain snapped and there was NO oil pressure but oil in the sump. I did not notice it until the engine stopped and seized. It would not turn over and there were metal to metal scratching sound when turned. I resurrected it by replacing the rod bearings ONLY. Sanded the crank journal a bit, only 1 out of 5. Honed the cylinders slightly and now it is running like a champ. You really do not know until you take the top and bottom off and inspect them. I would not discount it yet.

When oil pressure is lost gradually, the rod bearings are the first to go. You might get away with just replacing those. If you are less lucky, you might need to pull the crankshaft and turn the rod bearing journals down to the next size. If you're that far in, you'll be inspecting the main bearing journals and replacing the main bearings. The top end is probably ok. However, if you were looking for an excuse for a full rebuild, this is it.

When I was 16, I did the exact same thing to a 400 Chrysler V8. I ran it low enough long enough that the crank would have needed to be turned. I didn't like that car very much anyway, so my solution was to get a different car.

I would cut the oil filter open and see if you have any metal particles stuck in the element. You could also carefully drain a cold, settled quart of oil from the pan and strain it with a coffee filter to see what you've got.

Looks like getting at the rod bearings means pulling the engine? I'd think the oil pan(s) need to come off, correct?

It is apparently still running.
New filter, fill with oil, drive it.
Don't ignore the low oil warning light.
If the low oil warning system is not working then check the oil level often.

If it seems to run ok, start looking for where the oil is going.
A faulty CCV system can suck oil out of these engines pretty quick.

Yeah sure, keep driving it. Maybe the bearings will burn out enough that you'll throw a rod through the block and have an entirely new can of worms opened.:rolleyes:

Cut that oil filter open, it's the easiest way to tell if you engine is making metal, though if it's knocking the damage is likely done. Once you block a oil hole with babbet/metallic meterial it's only a mater of time before you lock up a rod bearing and bust a hole in the block.

Does this engine have oil jets that lubricate and cool the pistons from below?

I would not run the car now until you have inspected the rod bearings. You can change/inspect the rod bearings by removing the oil pan only and lift the engine up a bit. You can also inspect the main bearing by gently tapping/rolling them out of the crank shaft. Good luck.