CRUSADER 502 USING ONE GALLON OF OIL AN HOUR

[Fred K]

Was cruising down the river towards Mobile with twin Crusader 502 engines and the starboard engine started to use more and more oil by the hour until after about 5 hours, it was using a GALLON of oil an hour. Shut the engine down and limped on in on the port engine.
There was no sign of excessive burning of the oil such as smoking (other than the normal steam from the exhaust), nor was I able to locate any leakage in, under or around the engine. I did top off the engine with a gallon of oil until it was at the "Full" mark and started the engine. I placed my hand in the exhaust for about 10 seconds. When I removed my hand, it had a slight oily feel to it and a faint smell of oil. I did the same to the port engine and there was no oily feel or smell. (Oh, and the port engine uses about a quart maybe every 30+ hours.)
I am still looking for possible answers.

 

[Bruce Herrington]

How many hours on the engines? I'm no motorhead, but sounds like it's burning it if you find no leaks.

Had a '79 Bronco with a 400 v8 that burned a quart every 200-300 miles and never smoked.

 

[Golfman25]

Possible leaking oil cooler?

 

[alk]

Only a few places that this much oil can escape. Assuming there isn’t oil all over the engine room, Golfman’s suggestion of oil cooler is probably the culprit, and oil is dumping into the water in the cooler. I think it’s also possible that there is an internal engine leak. Do you have functional oil pressure gauges, and if so, what did they show? Maybe pull the spark plugs and examine it to see if any are soaked with oil?

 

[boatbum]

I agree if none of the plugs are showing serious contamination or have a nice cocoa color, something basic like an oil cooler is leaking. I'd start with a pressure test of the cooler after checking the plugs.

 

[Fred K]

Only a few places that this much oil can escape. Assuming there isn’t oil all over the engine room, Golfman’s suggestion of oil cooler is probably the culprit, and oil is dumping into the water in the cooler. I think it’s also possible that there is an internal engine leak. Do you have functional oil pressure gauges, and if so, what did they show? Maybe pull the spark plugs and examine it to see if any are soaked with oil?

Pulled all the plugs and they had no oil on them and hey were not fouled either.

 

[DeeVee]

Do you have a PCV "Positive Crankcase valve" or something like that that connected one end to valve cover and other end to intake manifold and or carb/EFI base? If the valve and or system goes bad it'll sucks the oil from the crankcase and burn it without little or no visible smoke. Just a thought.