Motorhome drinking oil

I had a '97 SBC with a bad valve stem seal suck approx 1qt per 600mi when I was on a trip from UT to CO. I did have a cold misfire at idle. The problem cylinder had heavy ash deposits on the spark plug. I could not see any smoke from the pipe.

A 'quick' test would be to pull the spark plugs and inspect for abnormal, this would tell you which cylinder(s) are having an issue. Leak, rings, or valve stems.

Keep an eye on the oil level and when you get home, take it to a shop and have the motor rebuilt.

90K in a Mo Ho, it's time.

1/2 qt in 500 miles but how much in 1000 miles? Many engines will use a half at and stay there for many miles. You don't need to add until it gets to "add" our almost.

K Charles wrote:
1/2 qt in 500 miles but how much in 1000 miles? Many engines will use a half at and stay there for many miles. You don't need to add until it gets to "add" our almost.

I agree, a qt to 1000 miles is no big deal. I don't think the manufacturer would fix that even if it was still under warranty.

Next oil change make sure you check the level immediately after to verify the full mark. Slight overfill can burn more oil.
Fill by capacity specification not the stick.

I’d be tempted to slap a pcv valve in it- cheap and cannot hurt.

Thanks for the great input from all you knowledgeable people! Puts us at ease for the rest of our trip.

PCV could such some oil as Chris said.
Quart every thousand miles is not that bad for Chev big block.90,000 miles should not need engine rebuild.
You may even put Seafoam in crankcase and run it to clean system. Run for 1000 miles before next oil chaange.
We have nearly 200,000 on 7.4 miles and uses a quart very 12-1500 miles. This depends on how hard the engine is working.

K Charles wrote:
1/2 qt in 500 miles but how much in 1000 miles? Many engines will use a half at and stay there for many miles. You don't need to add until it gets to "add" our almost.

I agree with this. Many times an engine will seek it's own level and stay there for many, many miles.

90,000 miles is not much for the GM 8.1L engine. On my 8.1L engine, I used the 2 quart oil filter instead of the 1/2 quart standard filter. This increased my oil capacity by 1 1/2 quarts. I then started filling the crankcase to the BOTTOM line of the normal range on the dipstick.
The point is I was not running the engine low on oil but I noticed that the amount of oil used dropped dramatically. I believe that the marks on the factory dipstick are too high.
Naturally there are many places where oil can leak. I would get under the coach and look closely for any oil traces on the undercarriage that would indicate a leak. The rear main seal could be leaking, rocker cover gaskets, etc. It could also be something as simple as your valve seals hardening.
A simple compression check will give you a basic health report on your engine but I am sure that you will find that your engine does not need to be rebuilt.