Blogs Car Info Our Show Deals Mechanics Files Vehicle Donation

Engine burning oil

my 2003 silverado is burning oil. there is no oil on the driveway or on the engine. there is no water in the oil either. is there anything that can be done besides dropping a new engine in it or reboring the engine?

The oil is either going past the valve seals or the piston rings.
There is no test for valve seals as that is a replace and hope option.
A leakdown test could be performed to test for ring leakage but even that test is not a 100% surefire test.

Reboring (which could be necessary depending on cylinder scoring or measured specs) would mean a complete engine overhaul.
Ring problems are caused by plain old wear, loss of tension or seizing in the ring lands due to overheating, or seizing in the lands due to oil sludging or coking. (sludging due to lack of regular oil changes and coking due to overheating)

For another hope and pray option you could check the PCV valve and make sure that it’s not stuck as this could cause the crankcase to pressure up and in turn lead to oil loss.

replaced valve seals and still leaks. truck has been serviced regularly at chevy dealer. only way i found out is the black soot on the truck by the tail pipe. where is the pcv valve and how do i check it? thanks for your help ok4450.

Off the top of my head I don’t know exactly where the PCV is located on this model. They’re usually between the intake tract and a valve cover. When you find it just take it out and shake it. If it rattles like a rock in a can it’s good. If it doesn’t rattle or if the rattle is erratic or muffled then it’s faulty. They’re dirt cheap and easy to replace anyway.

Just curious, but how much oil is this thing going through? As in how many quarts per 1000k miles or whatever.

A preliminary test of the rings could be done with a simple compression test. This is performed on all cylinders and is called a “dry” test. If there is an abnormality (lower compression on one cyl. as compared to others or what appears to be lower than normal readings across the board) then the test should be performed again as a “wet” test. This means that as each cyl. is tested a squirt of oil is added to the cylinder before it’s checked. If the reading takes a healthy jump up as compared to the dry test then there’s a ring problem. Hope that helps.

im gonna check the pcv and hope for the best. ive had to put in as much as 3 quarts between oil changes when i first noticed it. now i check oil level weekly and put in a quart every 3 weeks just to keep it filled.

i check oil level weekly and put in a quart every 3 weeks just to keep it filled.

How many miles is that between changes?

Except for adding oil, is there any adverse effect on the engine such as fouled spark plugs?

Let us know how far you go on a quart of oil. I was reading the owner’s manual for the 2011 Toyota Sienna that I just purchased. The owner’s manual claims that there isn’t a problem unless the engine consumes more than a quart of oil every 600 miles. Now I certainly hope that my new minivan doesn’t use this much oil. The 2003 Toyota 4Runner I own never needs oil between changes. Maybe Toyota is covering itself against oil consumption claims. My first car, a 1947 Pontiac for which I paid $75, used a quart every 250 miles. It got me where I needed to go, but I checked the oil every time I bought gas.

i recently changed the plugs and i did not see anything wrong with any of them. i expected to see some fouling or excessive oil on them. off the top of my head id say i can go between 600 and 1000 miles before adding the quart. the engine sounds good, runs good until i punch it on the freeway where it feels sluggish and lower gas milage.