[stan_tampabay]

Hello, first timer. Have '97 Cadillac DeVille with 80,364 miles. Taking oil consumption test and dipstick currently indicating one section above add. Have used premium fuel until recently when on advice of experienced service tech,changed to mid-grade. Believe that premium may have been causing carbon buildup in piston rings causing them to stick and using more oil than it should. With mid-grade carbon buildup could be dissipating due to a faster burning fuel than premium and therefore burning off that carbon. Any opinions or suggestions? Thanks very much.

 

[EcSTSatic]

Welcome Stan Faster burning fuel? Premium causing carbon buildup? Who's been feeding you this stuff?

 

[sjwoodruff]

Hello, first timer. Have '97 Cadillac DeVille with 80,364 miles. Taking oil consumption test and dipstick currently indicating one section above add. Have used premium fuel until recently when on advice of experienced service tech,changed to mid-grade. Believe that premium may have been causing carbon buildup in piston rings causing them to stick and using more oil than it should. With mid-grade carbon buildup could be dissipating due to a faster burning fuel than premium and therefore burning off that carbon. Any opinions or suggestions? Thanks very much.

My suggestions...

1) save some money and run 87 octane. You won't notice a difference in performance or economy most likely, especially in the warm climate you live in. I have a '98 STS, run regular and get over 29 mpg on long highway trips, about 21-22 mpg around town and about 25 mpg on an average tankful.

2) do the Wide Open Throttle procedure with your Deville a couple times per month, or more if the spirit moves you. Basically, this cleans the engine up, reseats rings, improves economy and oil consumption and generally lengthens the engine's service life. You'll find the procedure in the technical archive section at the top of the screen.

Welcome to the board.

 

[mcowden]

Hello, first timer. Have '97 Cadillac DeVille with 80,364 miles. Taking oil consumption test and dipstick currently indicating one section above add. Have used premium fuel until recently when on advice of experienced service tech,changed to mid-grade. Believe that premium may have been causing carbon buildup in piston rings causing them to stick and using more oil than it should. With mid-grade carbon buildup could be dissipating due to a faster burning fuel than premium and therefore burning off that carbon. Any opinions or suggestions? Thanks very much.

Mid-grade fuel isn't going to help you at all. Whatever "experienced" tech told you that doesn't know what she/he is talking about. You can run regular unleaded with no problems, but it won't help ring carbon issues. You need to put the transmission in 2nd gear and put the pedal on the floor up to almost 6000 RPMs and then take your foot off the pedal completely and drop down to about 2000 RPMs, then pound it and do it all over again. Do that about 10 times, obviously being extremely careful about traffic and Mr. Law Man. That will do far more to clear out carbon from the rings than changing grades of fuel.

The Northstar engines do burn some oil, and that's a good thing. Up to about 1 quart per 1000 miles is OK. More than that and you might have some other problem or a leak. The wide open throttle maneuver described above and in the Technical Archives (top of the page) will help clear out carbon that results from the oil consumption.

Oh yeah, and tell that "experienced service tech" to come on over here and read up. She/he might learn something useful. I'm particularly interested in how mid-grade fuel "burns faster" than premium.

 

[powerglide]

........do the Wide Open Throttle procedure with your Deville a couple times per month, or more if the spirit moves you. ........

"Sorry officer, the 'spirit' moved me!"

 

[mcowden]

"Sorry officer, the 'spirit' moved me!"

LOL... That's a good one too. I once tried to convince a police officer that he couldn't have known how fast I was going due to the Heisenberg Uncertainty Principle. As hard as I tried to persuade him that the radar gun would not have been able to determine my exact position, he remained unconvinced and, I might add, quite unamused, though he never tried to argue Occam's Razor against me. I just tucked my tail and drove home at 55 MPH with my new $75.00 speeding ticket in hand, thankful there was no citation for being a smartass...

 

[powerglide]

LOL... That's a good one too. I once tried to convince a police officer that he couldn't have known how fast I was going due to the Heisenberg Uncertainty Principle. As hard as I tried to persuade him that the radar gun would not have been able to determine my exact position, he remained unconvinced and, I might add, quite unamused, though he never tried to argue Occam's Razor against me. I just tucked my tail and drove home at 55 MPH with my new $75.00 speeding ticket in hand, thankful there was no citation for being a smartass...

yeah....good luck discussuing 13th century medieval philosphy with a guy who may or may not have recieved his GED in the mail.

One of my favorites is the one Dave Chappelle tells when he was riding in a car driven by one of his white friends, drunk and driving crazy. He gets pulled over and his excuse is "sorry officer, I did not know that you can't do that"....and he lets him off!

 

[Ranger]

:welcome:Go to the top left of this page, click on Technical Archives and read up on oil consumption. Fuel has no bearing on it. Octane rating is nothing more than the fuels ability to resist knocking. They all burn at the same rate. Lots of discussions on it in the archives. Use the search feature and read up.

​

 

[stan_tampabay]

Welcome Stan Faster burning fuel? Premium causing carbon buildup? Who's been feeding you this stuff?

What do you mean by that ? Stan_tampabay

 

[EcSTSatic]

What do you mean by that ? Stan_tampabay

My punctuation is missing. Mainly we're concerned that someone is feeding you a load. Read above comments regarding fuel and carbon. Or search. There's plenty of discussion on both topics.