I have an absolutely cherry 2007 LTZ with VIN Police Package. She has about 150,000 and I was lucky enough to tune out AFM/DOD not long after I purchased her. She has great oil pressure and runs strong. However, she had a catastrophic failure of a heater hose connection and overheated last summer; I can't detect any problems from that but I worry. I am aware of the oil pickup tube o-ring issues, the AFM/DOD issues, etc. so I want to do something to the engine and this is my conundrum. Should I - A) have my 5.3 8th VIN 'O' engine rebuilt with a stealth cam (243 heads) and if so, boost? or B) replace my 5.3 with a 6.0 or 6.2 performance engine? or C) do nothing and just replace my original water pump and continue to drive it until I'm forced to do something? Money really isn't much of an issue and I plan to keep her. She is not my daily driver, but I'd like whatever I do to not prevent her from being so. My daily driver is a 2004 Silverado with a weak (but runs well) 4.8 and if I replace my 5.3 I'd have it engine rebuilt and put into my Silverado replacing the 4.8. Your $.02 is as good as mine and some of you may have some experience that you'd share with me. Thanks, man.
Your thoughts/opinion would be very appreciated - engine ?
- Thread starter Streborel
- Start date
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wjburken
Supporting Member
Never say that here. These hoodlums here have no problem helping you spend your money.
Personally, If money truly isn't much of an issue, I would go with a 6.2 in the 2007, if you can find one that doesn't have AFM. Then take the 5.3L, do a full AFM delete any other sprucing up that is needed and put it in your Silverado like you mentioned.
Airman68
Member
I would agree with this. If your intention was to go with the 6.2 at some point, just do the min to the current 5.3 and drive it until that time. Next best thing is to do a full AFM delete on the 5.3.
my only experience with over heating was a aluminium ls3 that slung a belt at a track day, the Temps were already at 230ish coolent and pushing 300 oil when it happened. I should have killed it, but I limped it for a bit... it got hot enough to set a bunch of codes and go into limp mode, emptied it's entire radiator out the over flow. it was ugly.
but I cleared the codes, filled the radiator with bottled water and drove it a 1000 miles home. sent an oil sample out for a test when I got home expecting to rebuild it. but all was good, no sign of coolent in the oil from warped head or anything. chrome was bit high but that could have been cause I was hitting 300deg oil Temps during runs before backing off and doing cool down laps.
my 2 cents it's your probably fine, build a motor if you want. but I wouldn't worry about that one till you see some signs.
edit, I've since done a 2nd track day on it but with oil cooler mods byond the front mount and it showed down signs of damage. ran cool and I was almost 4 secs a lap faster by being able to push harder because I didn't have to worry about oil Temps. these ls engines are pretty solid other than the afm junk.
thats ls3 has almost 110k miles on it now.
but I cleared the codes, filled the radiator with bottled water and drove it a 1000 miles home. sent an oil sample out for a test when I got home expecting to rebuild it. but all was good, no sign of coolent in the oil from warped head or anything. chrome was bit high but that could have been cause I was hitting 300deg oil Temps during runs before backing off and doing cool down laps.
my 2 cents it's your probably fine, build a motor if you want. but I wouldn't worry about that one till you see some signs.
edit, I've since done a 2nd track day on it but with oil cooler mods byond the front mount and it showed down signs of damage. ran cool and I was almost 4 secs a lap faster by being able to push harder because I didn't have to worry about oil Temps. these ls engines are pretty solid other than the afm junk.
thats ls3 has almost 110k miles on it now.
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Marky Dissod
Full Access Member
If you find one that has AFM, and money is truly not much of an issue, delete the V4 mode crap while it's out of the engine - and anything else you feel like doing to it while you can.
If the 4.8L still works well when you take out the 5.3L, show it some love too, before you put it in the Silverado.
Otherwise the horsepower will be barely detectable, and the torque while noticeable, will make you wish you'd done something more to the 5.3L before installing it.
OPM....I love it. Do the 6.2 asap and freshen up the 5.3 with an AFM delete and slam it in the Silverado. What the hell ever you do, stay away from the AFM and spend that money before you back down. Then sell the 4.8
iamdub
Full Access Member
It depends on what your goals are. The more power you have, the more supporting mods you'll need. You can't forget about the trans. You mentioned a "stealth cam", so I take it you're not looking to run 10s. There are some issues with the 6.2 that I'd address before dropping it in as-is. If boost is an option, boost the 5.3. You can get more power out of that than a stock or mild 6.2 and possibly for cheaper unless you get a deal on a 6.2. Again, don't forget about the trans. 150K miles on a well-maintained LS is nothing. I'd put 10 well-tuned PSI on it without a second thought. When cruising out of boost, you'll still have the fuel economy benefits of a stock, but tuned 5.3. Although, it won't be anything astronomical over bigger cubes and I'm sure it's not much of a concern, given the Tahoe's purpose.
If you do swap the 5.3 for something, just know there are some considerable differences to be accounted for between the Gen3 in your Silverado and the Gen4 out of your Tahoe. Cam sensor location, knock sensor style and locations, 52x reluctor versus 24x reluctor on the crankshaft, etc.
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