well it doesnt make that noise unless i go mudding or somthin. so ill let you all know next weekend

 

I've heard that from several sources (some more authoratative than others), and it applies to most engines. This makes sense to me, as every engine I've ever had always burned off some of the (vaporized) oil through the PCV system.

As a general rule of thumb (so I've been told) is that an engine in good condition should use roughly 1/2 to 1 quart of oil per thousand miles.

I've also been told that if you have an engine that doesn't use any oil over a couple of thousand miles (dipstick level doesn't change much), that you may have a problem.

As it was explained to me, the oil is there to not only lubricate, but to clean and trap contaminants from the internal workings of the engine.

So, if you have an engine that does not seem to use oil (going by the dipstick), it means that something undesirable is causing the inside of your engine to be very dirty. The oil vapor would still be burning off through the PCV system, but the lubrication quality would be rapidly diminishing because of all the dirt that replaced the vaporized oil.

 

i don't know if that's entirely true or not i havn't heard that, the pcv valve doesn't use a lot of oil at all to my knowledge and i do know that all of the motors i have built don't use oil and i have been told that all of the car companies have that in the warrenty just because sometimes they get a motor that's put together on the loose side with tollerances and the rings don't seal as well as they should and they don't want to have to replace the motor

 

I believe that Ford said that the 5.0 vintage engines had to use more than 1 quart per 900 miles before Ford would consider it warranty issue when the trucks were still within the 3 year/36month warranty!!!

 

If your old oil is the same color when you change it after 3000 miles, as it was when you put it in, and your oil level did not change, then I'd agree that you are not using any oil, and that would be one impressively clean engine. But, if it comes out closer to black than the honey color it was when you put it in, I'd guess the engine is using oil, and the missing oil is being replaced by dirt.

From my own personal experience with some of my engines being about a quart low after about a thousand miles, and seeing how dirty oil gets after a few thousand miles, it sure seems like there is some truth to it. I have also heard of engines "making oil" before (not often, though), which isn't possible, so this would seem to lend some support to the theory, as well. (I've seen gas in the oil before, but that's not what I mean here.)

How much oil vaporizes, and gets circulated through the positive crankcase ventilation system, and out the exhaust pipe, is a question I don't have the answer to. I would expect it would vary by operating temperatures, typical driving distances, etc., since the oil has to get warm enough to vaporize in the first place.

The only way I know of to get conclusive evidence would be take oil samples when you put new oil in, and oil samples when you change the oil, recording the actual number of quarts, and ounces, at the beginning, miles driven, the actual quarts, ounces, drained, and sending samples of each off to a laboratory like Oil-Scan, to have them do an analysis to see how much dirt is actually in the oil, and how much oil vanished. It seems like more work than I'm inclined to do to find out the answer.

The auto makers want people to have a good experience with their vehicle, and want them, their family, and their friends, to buy their next car from them, too.

Between the normal wear, and tear clauses, and the consumer maintainence requirements that are spelled out in the owners manual, I would think that the auto makers are already well covered to avoid financial responsibility of repairs, if they choose to play it that way.

However, these companies usually care more about their corporate image than the minor (to them) cost of replacing the occasional engine for someone who got a lemon, and depending on the circumstances, will sometimes bend over backwards to make it right with the customer. It's a lot harder to overcome negative word-of-mouth, than it is to make up the cost of an engine swap.

P.S. to the original poster: Sorry for hijacking the thread.

 

I've had older engines, a '69 351W and a '70 429 that I don't remember them using oil. Especially to the tune of 1 qt per 1000 miles, although they may have used a little between oil changes depending on how hard I've run them. I've always thought that the 1 qt per 1000 miles usage began when Ford started using low tension rings on their pistons which I believe was around '85 on the 5.0s I'm not positive on this theory, but I have had some limited experience with the later 5.0s and 5.8s to back it up.


My apologies also for the hijacking, post here next weekend and let us know how it went for you!