04 Yukon XL burning aprox 1 qt per 1000 miles...no apparent leaks

[krazikarl5]

I have cleaned the underbody and no obvious signs of an actual leak after driving about 100 miles. This leads me to believe its burning internally. 2004 SLT 2WD with 240,000 miles on it. Where do I start?

 

[Tonyrodz]

Have you noticed the smoke coming out of your tailpipe? When you start it after it's been sitting overnight, does it blow blue smoke?

 

[S33k3r]

Personally, I'd just let it ride, and check the oil once a week -- topping of as necessary. If it starts getting worse, deal with it then, hopefully after saving up to deal with it.

 

[Scottydoggs]

pcv valve might be clogged solid with them miles. pull it out shake it, you should hear and feel a metal ball moving inside it.

 

[Marky Dissod]

pcv valve might be clogged solid with them miles. pull it out shake it, you should hear and feel a metal ball moving inside it.

Probably time to upgrade to 12572717.
It's a PCV thingy with a fixed orifice and no open / close mechanism.
It was designed specifically for a TSB that addresses oil consumption issues.
(It even works in previous GM V8s to help reduce -but not necessarily eliminate - oil consumption.)

You may also want to invest in some sort of catch can.

 

[PatDTN]

You won't have exactly the situation I had but my '09 Tahoe has 3 cats. Two by the manifolds and one after the Y. Both of the upper cats had melted and collapsed down into the 3rd blocking it. With nowhere to go the exhaust pressurized the block pushing the oil into the intake.

My point being something may have blocked your cats. I learned diesel oil contains zinc which destroys cats.

 

[krazikarl5]

Have you noticed the smoke coming out of your tailpipe? When you start it after it's been sitting overnight, does it blow blue smoke?

All spot on with the exception of it being blue. I would describe it as white.

 

[Doubeleive]

install updated "left" valve cover
install a catch can
be happy it isn't burning coolant instead.
ultimate solution, new rings
but at 240k it's not worth it, toss in a rebuilt engine if the rest of the vehicle is worthy and you plan to keep it for the long term.
just keep in mind you could buy a lot of cheap oil before you even get close to equaling out the cost of another engine

 

[SilverSport]

I've always read white smoke (other than cold start on colder days) is many times coolant related while blue smoke shows oil burning...

Good luck with yours

Bill

 

[Tonyrodz]

I've always read white smoke (other than cold start on colder days) is many times coolant related while blue smoke shows oil burning...

Good luck with yours

Bill

If the white smoke has a sweet smell also coolant.