New-to-me 5.3 oil burner...

[ACM]

Hey TYF! Mostly been lurking for the past few years; long time, no see...but I'm back and excited to report that I'm moving up to the GMT900 platform later today - via being gifted/loaned the black 07 LTZ in my sig during a cross-country visit from my folks. My family has christened him with the name "Rico Suave" or just Rico for short. I'll have to post pics soon, but take my word for it: for 225,000 miles he's a beautiful and well-cared-for truck, garnering compliments from the DMV folks who did his inspection today. Transmission fluid and both differential fluids were all just changed to synthetic prior to his drive here, the Michelin LTX's he wears have been rotated religiously by Discount, the infamous oil pump screen has been cleaned once (a few years back) and then replaced (last year).

However, we've got one somewhat significant remaining issue. My father reports that he not only leaks oil (which I could plainly see on the underside /crossmembers of the truck when I took a quick Spider-Man pose under it at my folks' hotel), but that he consumes oil to the tune of a quart and a half between changes. Yikes!

My question is this: I have an Amazon shopping cart full of upgrades for Rico, including the updated valve cover and the Moroso GM-truck-specific catch can. He's also had dino oil for his entire life, which I plan to switch to M1 synthetic tomorrow with an M1 filter, the longer optional size like I've been running on my 04 Yukon. All other things being equal and without me being able to get my hands on the truck for further inspection, what are the odds that those three changes - synthetic oil, a catch can, and the new valve cover - will help the oil consumption? Could this be an AFM issue that needs to be addressed via a tune/the Range plug-in? Am I maybe looking at a bad gasket somewhere that's seeping/leaking oil?

Thanks in advance for your collective two cents - as a long-time GM driver and relative newb to this platform, it's much appreciated.

 

[Danny3737]

If you have smoke smoke coming out of the tailpipe, I'd add valve seals to your shopping cart. You may want to do a compression check as well.

 

[ACM]

If you have smoke smoke coming out of the tailpipe, I'd add valve seals to your shopping cart. You may want to do a compression check as well.

No smoke that I can see...anything else to look for?

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[HiHoeSilver]

First things first. Lose the AFM. Then see where you're at.

 

[ACM]

First things first. Lose the AFM. Then see where you're at.

For sure. Are you thinking the full delete kit or just getting it shut off with a tune/plug in? 27 year old college senior here, living in a tiny mountain town on a budget...I can see this Amazon cart swelling to $1,500 if we add lifters to what I already have planned.

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[HiHoeSilver]

For sure. Are you thinking the full delete kit or just getting it shut off with a tune/plug in? 27 year old college senior here, living in a tiny mountain town on a budget...I can see this Amazon cart swelling to $1,500 if we add lifters to what I already have planned.

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I would just stick a range device in there first.

 

[swathdiver]

Well, you don't know for sure that the oil loss between changes is solely to the leak or for other reasons right? If that were my truck, the first thing I would do is identify and repair that oil leak.

 

[ACM]

Well, you don't know for sure that the oil loss between changes is solely to the leak or for other reasons right? If that were my truck, the first thing I would do is identify and repair that oil leak.

Definitely logical thinking, there. It's just, to me, the catch can and new valve cover are a combination of preventative maintenance and an attempt to solve the problem without throwing a bunch of empty labor costs at it. If I'm paying for labor, I want it to be because they're putting on parts that I'm not able to, not because they're circle-jerking and farting around on my truck trying to figure out the issue. That's why I have TYF [emoji6]

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[HiHoeSilver]

Well, you don't know for sure that the oil loss between changes is solely to the leak or for other reasons right? If that were my truck, the first thing I would do is identify and repair that oil leak.

This is a good point. I forgot we had a known leak here.

 

[iamdub]

Of course the leak is a problem and needs to be diagnosed and repaired. The catch can and updated valve cover should all be done regardless. For now, a tune or Range device to disable the AFM is a start.

After that, your oil consumption should be noticeably improved. If not, you've at least ruled out the easy stuff that's not a waste because they're necessary anyway and you can then move on to testing for more serious (but hopefully not detrimental) issues.

 

[Tonyrodz]

Just for the heck of it, I'd pull a plug from the left and right side, just to see if you have any fouling from oil on the plugs. If you do then that'll give you a good idea what's going on internally.

 

[swathdiver]

Well, my truck doesn't use any oil and AFM is still active. I never heard of a catch can before coming to this site. In my racing days, we put K&N breathers on the valve covers to keep oil out of the throttle body and or intake. Blow by is a high rpm thing, and I rarely spin mine over 3500; but it sure is fun when doing so!

The best way to solve problems such as these and when adding power adders is to make only one change at a time and then test/observe before doing the next. Throwing a bunch of parts at something is never as efficient.

 

[1yesfan]

AFM?

 

[Clive]

My '94 K1500 with 251,000 burns about a quart every 1000 miles. Seems about the same as your quart-and-a-half between oil changes (assume changed every 3000 so 1500miles = 1.5qts). No leaks on mine, so I've put it down to old age. $5/1000miles doesnt keep me up at night. I bet my compression is down a bit - I'd test that on your truck and see how much down it is.

 

[ACM]

AFM?

Active Fuel Management, AKA Displacement on Demand, or as I call it "Save the Whales" mode.

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[harbison]

The PCV valve is built into the left valve cover. GM redesigned the valve cover due to excessive oil consumption. I have had my 2009 GMC Yukon XL 5.3 2WD since new. Now at 208K. I changed the valve cover and cured the oil consumption issue. With 225K chances are the PCV is plugged up. This is a cheap and easy fix. I have used a Range AFM Disable but recently had AFM deleted from PCM by Engine Tune shop. Cost was about the same ($150). That way it's gone for good.

 

[wjoutlaw]

Try some Lucas Oil additive. Works wonders for engines that have slow oil leaks and or use/burn oil between changes. I ran that in my 2008 Tahoe until I got the Range AFM Delete module. It stopped the consumption issue. Now that I have the module I have driven it 2,000 miles and it hasn't used any oil so far.

 

[ACM]

If you have smoke smoke coming out of the tailpipe, I'd add valve seals to your shopping cart. You may want to do a compression check as well.

Ah, s#!t. After owning it for a few weeks, I am noticing white smoke from the exhaust on cold starts. Not huge clouds like some describe, but definitely noticeable. Usually goes away after it warms up.

 

[harbison]

I've had no more white smoke since changing the valve cover, which was a quick and cheap repair. Also oil consumption has gone down.

 

[iamdub]

Ah, s#!t. After owning it for a few weeks, I am noticing white smoke from the exhaust on cold starts. Not huge clouds like some describe, but definitely noticeable. Usually goes away after it warms up.

You sure it's smoke and not steam? Engines and exhaust pipes get water inside them from the moisture in the air condensing when they cool off and sit overnight. The condensation is heated to steam and blown out the exhaust during warm-up. Actually, when it's first started, you'll have sooty water dripping out of the tailpipe.