Why do GMC terrains burn oil?

A class-action lawsuit was filed against General Motors in 2019 stating that the excessive oil consumption is caused by faulty piston rings. Due to the faulty design, the engine burns about one quart of oil every 1,000 miles, causing damage and eventually engine failure.

What to do about excessive oil consumption in GM cars?

The engines have aluminum or cast iron blocks and are equipped with active fuel management systems (AFM). The fix includes installing an AFM oil deflector and cleaning carbon from the cylinder head.

Is the GM 5.3L V8 engine eating up too much oil?

Now, to be fair: Not every GM 5.3L V8 has problems with AFM. Many consumers report a trouble-free ownership experience. Still, AFM problems exist. The AFM excessive oil consumption problem usually crops up on vehicles that go on long highway drives.

What causes an engine to use too much oil?

Oil consumption, which most consumers define as an engine that uses more than one quart of oil every 3,000 to 5,000 miles. Engine problems due to fouled or damaged valves, which can be caused by the excessive oil consumption issue.

When to re-evaluate your engine oil consumption?

Re-evaluate the oil consumption. Important: Some minor scratches may be noticed on the cylinder walls during piston and ring replacement. If the scratch cannot be felt when running your finger nail over it, the scratch is considered normal wear and the block or engine should not be replaced.

What causes excessive oil consumption in a GM car?

That causes increased oil consumption and cracked or fouled spark plugs in cylinders #1 and/or #7. For vehicles with aluminum or cast iron blocks built prior to February 1, 2011 and with oil in the intake manifold, install an updated valve cover.

Now, to be fair: Not every GM 5.3L V8 has problems with AFM. Many consumers report a trouble-free ownership experience. Still, AFM problems exist. The AFM excessive oil consumption problem usually crops up on vehicles that go on long highway drives.

What happens if you put too much oil in your engine?

Then, at a certain point, excess ring and cylinder wear can lead to engine damage. After producing engines with AFM for a few years – and learning of oil consumption problems – GM developed a partial fix. A shield was added that keeps the oil from being pushed out and sludging up the pistons.

Re-evaluate the oil consumption. Important: Some minor scratches may be noticed on the cylinder walls during piston and ring replacement. If the scratch cannot be felt when running your finger nail over it, the scratch is considered normal wear and the block or engine should not be replaced.