What is the life span of a engine that has been rebuilt , i mean rebuilt as in head and cam [ mild cam] im @ 126000. All sythetic oils recent rebuilt trans .thinking of adding some heads and cam well actually i dream of this mod.......

 

Well that's not really what most would consider a rebuild, but I know someone with over 300k on a stock 5.3 and it still runs like new. Yours could easily go another 100k or more.

 

thanks for the long forcast for my engine i plan to keep it if i dont crash it first..

 

My 1999 with 4.8 has 210,000 original miles on it and i just got back yesterday from driving it from TN. to NY and back, 1150 miles each way and it did great and uses absolutely no oil. Ive seen lots of the ls engine trucks with 200 to 300,000 miles on them still running good, i dont know if this is common with these engines to go that long but ive seen many

 

You can get 200 easy out of these motors.

I have a 2000 silverado with a 4.8 with 205000 and we have beat it many times. It has been offroaded and just held right at 6k. It still runs just fine, makes a little more noise but thats kinda expected. This engine is going to be rebuilt soon.

We also have a 2001 GMC Sierra with a 4.8 with just over 200000. It runs and drives like it is new. The engine is quiet, tight, makes normal power and burns no oil, no vibrations. There are no plans to even touch this motor as there is no point.

So what I am saying is it really depends on how you drive it. Drive it like you stole it and a rebuild might be needed sooner around 200,000 like mine. Take it easy and i can see 300 outta the Sierra easily.

 

I would suspect if built correctly with quality parts it should last as long as an OE engine.

 

My 5.3 at 225,000 miles still had over 180 psi cranking pressure dry, and 190 wet. still gets over 20 MPG on the hiway at 241,000 as long as keep my foot out of it. That's with 3.73 gears. Take care of it, and it will take care of you.

 

All on how the first start is done...if you start it up try ur fu**ed if its a new built or re man turn it over with out plugs in it so oil pub the cam bearings

 

Yep..... No problem getting 200k plus out it. I have 260k on mine and I have no problem driving places. And I'm not easy on it either. I have FULL confidence in this motor that I'm planning eventually putting some small boost to it.