Chuzz, I finally got time to tear the engine apart with 186,700mi. with a friend who is my mechanic. My push rods and rockers were worn, some lifters were packed with crud like sand/oil paste but soft. The cam was fine. There wasnt any real buildup of black stuff under the valve covers or under the valley cover. We also took down the oil pan, 1" of black goop in the bottom of the whole pan, the oil pickup screen was completely clogged. I cannot believe this engine never blew! I tried the sea foam treatment, I tried the 5 quarts of transmission fluid flush and I still had the engine tap. So after checking all of the engine components we replace everything except the cam, pistons, connecting rods, bearings. I hindsight I probably should have just purchased a long block but we didnt know that we were going to get so far into it. The bottom line is the 5.3L engine is now quieter then when I bought it. i just drove it home. I will post the photos I took with my cellphone to a webpage so you can see what I was up against. I will post the link when they are up. Thanks again for all of your suggestions. I still cannot believe the condition of the engine using synthetic oil. I may have had a small antifreeze leak in a gasket and that may have contributed to the gunk building up.........anyway its like new now and I am a happy Tahoe owner once again!!!!!!!!!!!!!!!!
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Tary substance in 100% synthetic oil change........
- Thread starter jcy110
- Start date
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Hey John, if that had been me, I'd have gone ahead and put new main bearings and rod bearings in it too. You had the engine down far enough to have done that. I'm still wondering what caused the sludge in the engine. I'd avoid the Walmart brand oil and run something like Mobil One (what I use) or Castrol Syntec (which I still use in my 200,000 mile Caravan). Sometimes trying to save a few pennies can cost you in the long run. Stay in touch and let us know how the engine holds up over the next 10 to 20,000 miles.
You can see the pic of the sump in the oil pan before it was cleaned, the drain plug is at 11 o'clock in the photo. Also the old and new oil pickup. The top of some of the push rods were worn. For the other pics I just took them as we progressed.
Here is the link to the 49 photos, I probably should have just purchased a long block.............http://www.1pcmedic.com/tahoe
Now the engine is quieter than when it was new.
Here is the link to the 49 photos, I probably should have just purchased a long block.............http://www.1pcmedic.com/tahoe
Now the engine is quieter than when it was new.
Man, the only engine I've ever seen sludged up like that was a slant six in a 66 Dodge Dart that I rebuilt for an uncle of mine. He ran straight 30 weight Quaker State motor oil and the cheapest filter he could find. I suspect that the original owner of your vehicle did pretty much the same thing. It doesn't look like it had regular oil changes with good quality motor oil or filters to me. But then again, I'm not a mechanic.
I am the original owner................ran synthetic ever since the first oil change......I can't figure it out either. As long as I caught it in time and can get another good run out of it I will be happy. Just doesn't make sense though. I will keep you posted if anything else comes up. When I looked into the pan I shook my head and said "are you kidding me".
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What brand of synthetic were you using and how often did you change it? Also, which brand of oil filter did you use? I'm only asking because I've used both Mobil One and Castrol Syntec for several years and have never seen anything like that. I also use Purolator Gold filters exclusively.
Hmmmmm, I'm gonna stay away from the Walmart brand oil and I never use Fram filters. Had a bad experience with some back in the 80's and have not trusted them since then. Once again, it's just a personal choice on my part. I know a lot of people that use Fram filters and have never had any problems at all.
Well, if you had an anti-freeze leak into the oil, I would have thought you'd have gotten the infamous "milkshake" look either in the oil or the radiator. That one's probably going to remain a mystery, but I'm still not going to buy Walmart brand oil. Call me paranoid, but I'll stick with Mobil One.