Itermittent Smoking Problem 2004 GMC Yukon

[StrandedinNY]

Need some help figuring out a problem. 2004 GMC Yukon 2WD 5.3 L with 130,000 miles. Never any problems with this vehicle. About 2 months ago noticed 1-2 ocassions of smoking - white large plume of smoke from the exhaust after the vehicle had been parked for a few hours. Could shut the vehicle off or drive a short distance and next time started - no smoke.

Check engine light came on around that time and code indicated a Mass Air Flow Sensor (P101?).

Code was cleared and continued to drive daily last 2-3 months only noticing this maybe one other time. Vehicle has been running fine, normal gas mileage, no overheating, no visible leaks, plenty of coolant, etc...

Left GA Wednesday on a family vacation to NY. Check engine light came on again while driving. Stopped for gas in Ohio and when the vehicle was started, large plume of white smoke. After parking and shutting off the vehicle - restarting it - once again a plume of smoke. Pulled over - shut off the vehicle and waited a few minutes...started again and no smoke. We drove on and stopped to have the code checked - once again it read a Mass Flow Sensor - they cleared the code again. It has not come back on since.

After clearing the code and the smoke ending - we continued to drive. Once we reached NY and stopped at the toll - oil pressure suddenly dropped to nothing and engine started to knock. We found the first exit and added oil which was extremely low. Again - no visible leaks and no indication oil was low previously.

Since reaching NY it has had a oil and filter change. We have driven another 50 miles or so and watched the oil level carefully. It has not dropped. We continue to "sometimes" fill parking lots with smoke when starting the vehicle, sometimes after idling at a red light for a few minutes and accelerating - it smokes. Sometimes...it stops completely and there is no smoke.

Very little soot in the tail pipe, it is not wet, no dripping, no oil under the vehicle or on the motor. Any ideas? We have a 1000 miles to drive home and are trying to decide if we can make it or if we should put it in the shop here and take a rental home. Have no real idea what is causing this since the vehicle seems to be otherwise running ok. Any help much appreciated.

[maxwedge]

Lots of info but what color is the smoke, blue?, if so something is going on the engine causing it to burn oil , If no coolant loss that normally would indicate no issue with a intake or head gasket, but the loss of oil seems to connect with the smoke. Not good to get so low it knocked, if you keep the oil and coolant full sounds like you should be able to drive it, but without a diagnosis as to the problem, it's a gamble.

[StrandedinNY]

Smoke is white - not like a normal oil smoke but no coolant loss at all either. Strange thing is how it starts smoking and stops smoking under the exact same circumstances. No indication it was loosing oil until that incident at the toll booth. But no, the knocking wasn't good at all. Just can't figure out how the Mass Air Flow sensor ties in and why one stop there is enough smoke to fill an intersection....and the next stop there suddenly may be none. Trying to find a local garage this morning to do some diagnostic.

[yukon6inchlift]

if u lost that much oil and put out as much smoke as u did it must oil being burnt. i would think u lost a seal someplace

[StrandedinNY]

We made it home. Drove roughly 1000 miles and it didn't smoke again - not once.

Has not smoked with regular local driving since returning home 8/31. Still have no idea what exactly is causing this intermittent problem.

Watching it closely - no oil or coolant loss. Very odd for it smoke that much and loose that much oil and then suddenly just stop without any repairs or changes.

Thanks to everyone who responded. Will continue to watch closely and will check it over again in the event of any fluid losses or smoke.