neon14 Posted March 14, 2014 Report Share Posted March 14, 2014 At work we have a 1993 international bus with a IDI 7.3 non turbo engine. 140,000 miles. Its always used about a quart of oil every few hundred miles for years but over the last 6 months its really started burning some oil. Right at a quart every 50 miles. The exhaust smells real bad but it doesn't smoke excessively. I have changed the CDR valve and made sure the air pump isn't the culprit. Engine has no external oil leaks. I have tried lucas and a BG engine cleaner and that didn't help at all. Engine runs great, in fact it runs better than its sister bus that doesn't use any oil. Also doesn't seem to have any more blow-by than the other bus. I have not done a compression or leak down test. Anyone on here have any suggestions on what might be the problem? I'm thinking rings or valve seals. Oil getting into the fuel thru the injection pump maybe? Link to comment Share on other sites More sharing options...
thumper Posted March 17, 2014 Report Share Posted March 17, 2014 My 7.3 uses oil as it gets dirty.Doesnt burn when clean but after about 1000 miles on clean oil it takes a quart to go to the races and back.I use Rotella 15/40.I do have a ring problem,about 350,000 miles on engine.Bumping up the timing helped a little.Do you change the oil often? Link to comment Share on other sites More sharing options...
neon14 Posted March 18, 2014 Author Report Share Posted March 18, 2014 I have changed the oil 3 times since last summer! Once for a normal oil change, again when I replaced the oil pan gasket and another when I did that BG engine treatment. But before I came along I have no idea how often the oil was changed. I would say its got worse since the BG oil thing. I started to check the compression the other day but realized I could only get the gauge to fit on a few cylinders because hard lines and water neck were in the way. So I stopped just don't have the time to mess with it right now. I'm just perplexed because this thing starts and runs so dang good. I wonder if it is possible for bad valve seals to use a quart every 50 miles? Link to comment Share on other sites More sharing options...
jwmbishop Posted March 19, 2014 Report Share Posted March 19, 2014 I wonder if it is possible for bad valve seals to use a quart every 50 miles? Yes. Especially if the guides are wallowed out as well. Link to comment Share on other sites More sharing options...
sm002 Posted September 1, 2014 Report Share Posted September 1, 2014 I worked on a 7.3 turbo a while back and it would use at least a quart on a 30 mile trip. No smoke no misfires no leaks ran great and we decided to try replacing the injector o rings not a problem since Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.