2005 Trailblazer Oil Consumption

[Dazed]

I have a 2005 Trailblazer EXT and change the oil about every 5000 miles. Twice now, the engine has been 4 quarts low between oil changes. Both times, I was on a trip where I was doing a lot of high speed driving (70 - 80 mph). The engine will make a noise like the lifters are going bad. There is no sign of any oil leak and the tail pipe is clean. I had the lifters replaced under warranty at 36000 miles and this problem started about 10000 miles after that. I currently have about 54000 miles on the odometer. Has anyone else experienced this problem? Where is the oil going?

 

Thanks

[minibike132]

Hi Dazed, I may give info you know so bear with me I just like to cover everything I can think of. First off I can only assume what engine you have there so I'm going to guess it's the 4.2 since that is the most popular. That engine should take 6.5 quarts at oil change and alot of people short them right off the bat. Second the allowable oil consumption is 1qt every 2000 miles so you would be allowed 2.5 at 5000 miles. That is going to leave you with 1.5 unaccounted for assuming the level was right at oil change. I know you just had lifters put in but that doesn't mean the top end got cleaned so if you have a bunch of sludge up top and you jump out at the gas station and check it right away you can have a bunch sitting up top still. Let it sit for a minuite or two to get it all drained down. Last if your not seeing any external leaks that only leaves it to be getting burned. I would think 4 quarts would show up in the tail pipe but maybe not. You need to check that the PCV system is working correctly because that can suck up a major amount of oil. If all is ok with the PCV and your not seeing anything on the ground and it's not staying up top there is only one thing left that I can think of and that calls for some engine teardown to find where it's going.

[Dazed]

Hi Dazed, I may give info you know so bear with me I just like to cover everything I can think of. First off I can only assume what engine you have there so I'm going to guess it's the 4.2 since that is the most popular. That engine should take 6.5 quarts at oil change and alot of people short them right off the bat. Second the allowable oil consumption is 1qt every 2000 miles so you would be allowed 2.5 at 5000 miles. That is going to leave you with 1.5 unaccounted for assuming the level was right at oil change. I know you just had lifters put in but that doesn't mean the top end got cleaned so if you have a bunch of sludge up top and you jump out at the gas station and check it right away you can have a bunch sitting up top still. Let it sit for a minuite or two to get it all drained down. Last if your not seeing any external leaks that only leaves it to be getting burned. I would think 4 quarts would show up in the tail pipe but maybe not. You need to check that the PCV system is working correctly because that can suck up a major amount of oil. If all is ok with the PCV and your not seeing anything on the ground and it's not staying up top there is only one thing left that I can think of and that calls for some engine teardown to find where it's going.

 

Sorry, I meant to give the engine size. It is the 5.3L 8 cylinder. I do the oil changes myself, so I know for a fact that the last oil change was the correct amount. If the engine is going to "use" that much oil, I just need to know it so that I can make that part of my maintenance. The strange thins is that it did not use oil at all until the after the lifters were replaced.

[Draenor]

I would try running a can of Seafoam. See if that cleans out the top end. As Mike mentioned, check the PCV valve. Have you pulled your plugs and inspected them?