Bummer. Blow-by

Well, after 130K miles, it looks like some seals in my 5.3 engine are starting to do. It's nothing drastic but every few months roughly a quart of oil gets eaten. I asked my mechanic how much a rebuild would be and he flatly said it'd be cheaper to install a new engine. This sucks because I like this truck, but I gotta wonder if it's worth it in the long run. I hate monthly payments, but will I get another ten years out of the rest of the truck to justify the cost of a new engine?

I hate payments too even if it's a 0% loan. Tough call. Gotta weigh replacing all the other wear items.

Factors of consideration might be:

Another 10 years on a 10 year old truck without a doubt will have notable repair and maintenance cost.

Is it visibly smoking? Performed a compression or leak down test to see if it's truly a blow-by issue and if a particular cylinder is the culprit? Putting in a quart every few months is nothing if that's all it's consuming. I wouldn't think twice about it.

How much would a lightly used or reconditioned long or short block cost these days? I had a short block rebuild with reality stout internals, rod main bolts, forged pistons, Celvite 77 bearings for $1500 about a decade ago. What's a budget build cost today with all the machine work? $2500?

No one likes vehicle payments, as prices in the past 10 years have exponentially increased. It's getting plum ridiculous now.

How many miles does it take to consume a quart of oil?

Consumer reports has been seeing oil consumption on many none domestic cars for some years now and it is considered normal.
http://news.consumerreports.org/cars/2013/07/consumer-reports-sees-oil-vanish-from-some-test-cars.html

What year is the truck and does it have AFM?

My Yukon goes through 1 quart of oil every 3,000 miles. It just hit 50,000 miles a couple weeks ago. GM says this is normal. Bull$hit! Had I read up more on the 5.3 oil consumption problem, I would neve have bought my Silverado in 2010.

There was a TSB released for engines with AFM and oil consumption. Part of it was change in the oiling system design of the valve cover and PCV system if memory serves me right.

My 6.5TD has ~35K on the replacement engine and I have to add oil between changes. Don't even know how much, just top off as needed before towing. 1qt/3k isn't too bad imo. Look at some of those foreign cars in that link I posted, much worse.

My standards as far as oil consumption is when it starts smoking enough to make a mosquitos crap themselves or when the gas and oil consumption equalizes .

Hilux wrote:

My standards as far as oil consumption is when it starts smoking enough to make a mosquitos crap themselves or when the gas and oil consumption equalizes  .

Isn't that considered just broke in.......for a 2 stroke Detroit!

joemac wrote:

There was a TSB released for engines with AFM and oil consumption.  Part of it was change in the oiling system design of the valve cover and PCV system if memory serves me right.

Yes, I receives A TSB for my truck, but not for my wife's Yukon. Same engine. I'll have to bring hers in and either they fix it or I'll take it to another dealership and trade it in.

Hilux wrote:

My standards as far as oil consumption is when it starts smoking enough to make a mosquitos crap themselves or when the gas and oil consumption equalizes  .

So far at around 39,000 my truck has not been burning oil. I think they made a fix before I got the truck, but I've read that it normally starts to blow by around 36,000 or so.

Mine's a 2002. There is black smoke out of the tail pipe every now and again. (My co-worker saw it when I stepped on the gas-hard.)

There has always been black on the inside of the tailpipe, I just never questioned it. Never thought of it, in fact. It didn't use/burn any oil until about a year ago. IF it makes a difference, I've always used a synthetic blend since I got it used with 50K on the odo. I switched to truck syn-blend before going to high mileage blend once the truck hit 80K.

When was the TSB?

Black smoke could be from the catalytic converter and fuel enrichment on acceleration. IMO, since it is out of warranty it is way cheaper to just add oil until it is a visible smoker. That may take 100s of thousands of miles even.

Gosh it was like 2009 for the TSB covering 2007 and up trucks and SUV's with AFM. Since yours is an 2002 without AFM likely it isn't the cause or the issue.

Seeing a visible black puff of smoke when under hard acceleration is a likely occurrence from many vehicles. The PCM going to power enrichment mode dumps quite a bit of fuel and usually goes well beyond stoichiometric AF ratio of 14.7:1 to somewhere in the 12:1 ratio range. This is not the best fuel efficiency or the most effective combustion burn range, thus the black smoke which can be common.

I would not think twice about adding oil to the truck, though certainly respectful if you want or desire to do something else, that feeling is hard to fight back once it starts.

Thanks guys. I'll keep adding oil. This truck has way too much history to just let go of.

It stood outside and guarded/blocked the garage door during hurricane Charlie, helped us bug out for hurricane Jeanne, pulled out numerous cars after the storms, pulled the old shop down, brought furniture to the kids, towed equipment for work, ect.

You can't just let something like that go without a fight.

Track the consumption in more detail and figure out how many miles you go per quart.
Is it due for a new set of plugs?
If so check to see if any one cylinder is showing signs of oil fouling.

A compression test will tell you if there's a suspect cylinder(s). Might consider doing an oil analysis with Blackstone to see if there are any indications from wear metals if there's anything to substantiate an issue.

I've heard people swear restore works. A respectable mechanic I know tore an engine down several years ago and said there was an incredibly hard green coating on most of the parts. Found out the owner had been using it. If you're thinking about replacing it I don't see how it could hurt. BTW, I know Lucas transmission treatment works, just don't know how long. My brothers 2000 Explorer has 320,000 miles and the transmission was shifting slow. For now it's working like new, think it swells the seals. YMMV.

In your brothers case the slow shifting could have been from a varnish buildup on the solenoids. Sometimes the "cure in a bottle" can clean that up.

Yep, sometimes cheap works.

I'll measure out the miles between oil needs. The plugs were changed out roughly two years ago when I had the major maintenance routine done.

The oil analyst and pressure test sound good, but will have to wait until funds get a little freer. (Helping an injured family member)

I have had trucks burn oil with synthetic oil and not dino. Not all, just a couple.

Our 2002 Suburban 5.3 burnt synthetic oil quicker than dino. In the end, I just used the dino on it.

Huh. And here I thought I was helping the truck. I'll go Dino next few changes and see what happens. (5W30 still ok, right? - Florida)