Excessive Oil Consumption GMC

[Princeton Auto]

2001 Yukon with 5.3liter. Engine has 112K miles. Customer complaining of excessive oil consumption. Using 2 qts of oil in about 500 miles. No leaks, no blow by, no oil in PCV system. Engine has been well maintained. Customer complains of slight blue smoke on start up in mornings but sees nothing while traveling down the road. Would he see smoke with that type of consumption? No evidence of oil in the throttle body area either.

What are the chances this engine is sucking the oil through the intake gasket or some other place.

[brianp87]

Never had it happen. The only newer gms I see using oil are the 8.1 l

[Pauls Automotive]

2001 Yukon with 5.3liter. Engine has 112K miles. Customer complaining of excessive oil consumption. Using 2 qts of oil in about 500 miles. No leaks, no blow by, no oil in PCV system. Engine has been well maintained. Customer complains of slight blue smoke on start up in mornings but sees nothing while traveling down the road. Would he see smoke with that type of consumption? No evidence of oil in the throttle body area either.

What are the chances this engine is sucking the oil through the intake gasket or some other place.

I had a similar problem with my Yukon. It was a 1998 5.0 litre however but the systoms fit. I would never see smoke while driving but had to put in 2 qts every 500 miles. Turns out the pistons rings were bad and burning oil. On my vehicle I could pull the plugs and a couple were fauled bad from oil. If I remember correctly it was he center two plugs on each bank. My machinist at the time told me GM was having a problem with those heads in that area running hot. Hope that helps.

[ricmorin]

I thought there was an upgraded pcv for this. Maybe 12572717? Can't find the bulletin right now. The new one is a fixed orifice rather than the old familiar style. Maybe oil drain back issue in head? Is it sludgy in there? Whats the crankcase vacuum? That's an easy check for an intake leak.

[steven kiser]

plugs will be the tell all. you really won't see oil burning unless it's a huge amount. the newer ash less oils combined with the newer engine controls make it almost impossible to see the blue plume of years gone by. a puff of smoke on start up would lead me towards valve guide seals and restricted oil return ports. ric covered the intake leaking issue in his post. another point (in my opinion) is that with that kind of mileage any major repair would be a lead in for an engine replacement. if the engine is running smoothly and the customer does decide to replace the engine i would do a pressure test on the exhaust to check for converter damage.