Hate to do it but I did search first -- oil consumption

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strad

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Engine is a 5.3, in a 2005 Z71 suburban, original to the truck as far as I know. It now has 219744 miles. Consumption is a small bit more than 1/2 quart per 1000 miles. Lots of freeway usage on this particular oil change (we are 1000 miles in). I change the oil in this truck every 3000 miles, and the last several changes have been synthetic 5W30. it's always gotten 5W30, just not always synthetic.

I found a large amount of information on the AFM engines when I did my search, but not so much on my engine (which is an L59 per VIN). So what is normal? At what point is an amount considered unhealthy?

I also should mention that I found a small amount of fine metal on the drain plug pickup the last oil change, but I have no idea how many miles it took to get there, because checking that wasn't on my radar before. I know this engine is getting old, just not sure how to quantify that lol.
 

OR VietVet

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Are you for certain you have no leaks? Are you seeing any oil smoke, blue, when first start the engine or when accel like to pass someone? Your oil changes can go much further with full synthetic oil and a quality filter. The metal, depending on how "small amount" it is may not be abnormal with the engine mileage. Supply pic of that amount? Is your oil pressure normal, what you are used to seeing, and what is it at cold start and then idle after warm? IMO, the 1/2 quart could be ok depending on the condition of the engine. I was adding 1/2 quart between oil changes but saw no smoke or any oil on ground. Did eventually see seepage at the oil cooler block off plate.
 
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strad

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I do have oil on ground. I believe most of that is coming from the hydrobooster though (and I am losing a requisite amount of power steering fluid, which I replenish). The hydrobooster has a leak by what I believe to be an accumulator. I'm sure the engine leaks some oil too, just not all that much. And I know the oil cooler block off plate seal needs to be replaced.

As for smoke, no smoke observed. Oil pressure shows just below the middle cold at idle, actually shows right at the middle warm at idle, and shows about 50 cruising along at 70.
 

OR VietVet

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IMO, you could chase this for a long time. Especially since you have no oil smoke and know you have a small leak. I preach the basics here all the time. Start with the obvious and replace that oil cooler block off plate seal and I am getting ready to do the same thing so I bought a billet plate to go along with it because I am used to seeing the oe plates, made of pot metal, warp over time and new seal still does not seal it unless you use enough sealer with it.


https://www.amazon.com/LSX-Innovati...f=sr_1_5?keywords=72435&qid=1575761413&sr=8-5

The combination of the other oil leaks you stated, but did not go in to detail as to what they are, can all add up to your 1/2+ oil added every 1000 miles.


By the way, fix the hydroboost system leak asap. No matter how good an engine runs the most important thing on a vehicle, IMO, is the brakes. Don't mess around with that. The leak you talked about will get worse.
 
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swathdiver

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Engine is a 5.3, in a 2005 Z71 suburban, original to the truck as far as I know. It now has 219744 miles. Consumption is a small bit more than 1/2 quart per 1000 miles. Lots of freeway usage on this particular oil change (we are 1000 miles in). I change the oil in this truck every 3000 miles, and the last several changes have been synthetic 5W30. it's always gotten 5W30, just not always synthetic.

I found a large amount of information on the AFM engines when I did my search, but not so much on my engine (which is an L59 per VIN). So what is normal? At what point is an amount considered unhealthy?

I also should mention that I found a small amount of fine metal on the drain plug pickup the last oil change, but I have no idea how many miles it took to get there, because checking that wasn't on my radar before. I know this engine is getting old, just not sure how to quantify that lol.

Send off a sample to Blackstone Labs for analysis. Might even discover what those flakes are from.
 

HiHoeSilver

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I do have oil on ground. I believe most of that is coming from the hydrobooster though (and I am losing a requisite amount of power steering fluid, which I replenish). The hydrobooster has a leak by what I believe to be an accumulator. I'm sure the engine leaks some oil too, just not all that much. And I know the oil cooler block off plate seal needs to be replaced.

As for smoke, no smoke observed. Oil pressure shows just below the middle cold at idle, actually shows right at the middle warm at idle, and shows about 50 cruising along at 70.

For an L59, your stats aren't bad, although you do probably have a little leak somewhere. Look around the valve covers in addition to the block off plate. Pressures are good for this engine (35-45) idle, gets up a bit under load.

I would drop $28 on sending a sample to Blackstone just for fun. Especially with metal dust coming from somewhere.

At 219k, you've got another 100+k in there. When did you switch to synthetic? What filer are you using?

Agree with Ron, fix that hydroboost first.
 

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