Ok I just rebuilt my 305 shortblock .030 over with moly rings. It seems to be burning oil quite significantly. No presence of oil in the exhaust and no oil on the block. My questions are:
Is there maybe a mating issue with the new heads and the stock intake manifold? (sucking oil through the lifter valley)
Does it take awhile for the moly rings to set?

I dont know adding a quart of oil a week is kinda puzzling for a brand new engine.

 

I've heard those moly rings don't take long to set. Can you see it burning oil when you start the car, when you shift, or both? Has it gotten more difficult to start?

How is there no oil in the exhaust if it's burning so much? Do you get o2 sensor codes after extended idle? There should be no mating issue, as long as the heads haven't been milled all funky, then there would be other problems though. Are you losing any coolant? How does the car run?

 

How are your heads? New? Redone? Did some one forget the valve seals? (o-rings and umbrellas)

 

I built the heads myself from all brand new components. Umbrella valve seals.

No burning oil when I start it, so I would imagine the seals are fine. I don't see oil when I shift, so I think the rings are fine too.

It has gotten more difficult to start.

No codes whatsoever.

I dont know where the oil is going because I dont see it in the exhaust and I dont see any on the ground or on the block.

I am so confused.

 

i'd suspect it's sucking oil into an intake port

 

A quart a week may not be excessive, depending upon your mileage driven within a week...

 

That's what I thought. It's the stock intake manifold currently and it did look like it was in good condition when I had it off, but I thought maybe there was a mating issue with the new heads.

I only drive 150miles a week. Doesnt seem like its too many miles.

 

Also before I rebuilt the engine, it didnt eat oil at all (it burned the oil on startup...damn o-rings) So I dont know why it would change so much after I rebuilt the engine.

 

Let's see, you drive approxamately 150 miles a week and you add a quart of oil a week, which we all know a quart equals 32 oz. Sooo, if we divide that quart (32 oz.) by the number of miles you drive (32/150), that equates to about .21333333333333 oz. per mile. Hmmmm, that's almost a quarter oz. per mile. Sounds like you have a quarter mile car there. Sorry, just started my 2nd cup of coffee this morning

 

I've also noticed at idle, after a bit the RPM's vary a bit. It's still the stock PROM, but could the oil in the exhaust be causing the erratic idle? No codes are thrown.

 

Do you still have your cat, maybe that's why you're not seeing any oil in your exhasut, it's all being trapped up in the cat.

 

Nope the cat is long gone.

My car's a mess, now it's using fuel like mad. The only parts I haven't replaced are the TPS, MAP and coolant sensor. Mannn I can't afford to keep on filling up.

 

Well I guess I dont feel as dumb anymore posting this question.

 

This took so damn long to load that I forgot what I was responding too, lightning fast T1 my ***..


Anyway, um.. You're not noticing any leaks or seeing any smoke? Really bad gas mileage.. I noticed that when my rings went, are you sure everything is fine down there?

 

You can check for an internal vacuum leak by doing the following:

1. Remove the PCV valve from 1 valve cover and the breather tube on the other valve cover.

2. Plug both holes with your thumbs with eng idling.

You should feel nothing or a press building.

If a vacuum is felt, you have an internal vacuum leak.
This will cause idle problems just like any vacuum leak would.

This problem is commonly mis-diagnosed.

 

I'll try that vaccum test soon and see if my vaccum is up to par.

I'm also going to replace the head gasket soon and I'll check my cylinder walls.

All your suggestions are great, Im just running out of ideas.