jeepnut24

Well my motor showed up today and the transmission should be here soon as well.

Im looking for suggestions on what to look over on my higher mileage 5.3. Its a 2002 with 112K on it. Id love to do a full rebuild, but I can't at the moment. The oil pan has to come off for a shorter version, and I think Im going to tap the water pump for the steam vent so it and the TStat are getting removed as well. Anything else I should try and cover now?

ls1nova71

iTrader: (4)

112K isn't really that high of mileage for a genIII, I've seen thes engines with 300K on them. Since you're putting a different pan on it, definitley put a new o ring on the pick up tube. Other than that you really don't need to do anything.

50chevy

iTrader: (2)

What I have done before on a higher miliage 5.3l swap is pull the oil pan and and valve covers to see how well the engine has been treated. Mine was perfectly clean, I guess that I was lucky that it got good oil changes. I would definately pull the intake manifold and scrub out all the oil and carbon deposits from the pcv system and wipe out the intake ports as good as possible. See if you can run a catch can setup to prevent that from getting gunked up again. Valve cover gaskets can be resusable (to an extent) but definately replace the intake gaskets as they compress over time and have vacuum leaks. If the rear main seal has signs of leakage replace it, otherwise leave it alone. Other than that, you should be good to go. Everything else is easy to service later on.

MeanYellowZ

iTrader: (19)

already said, but 112k is nothing really. I have swapped them in with 150k without question. At 100k these look like old school engines with 15k. Most will still have crosshatch in the cylinders and have no ridge, you can thank modern, efficient fuel injection for that. Gasket technology keeps these pretty leak free, even with some serious miles. My daily driver has 200k on its original 5.3 and it will outrun my buddies same truck with 100k. They really do last quite a while...as mentioned it's not uncommon to see these trucks with 300k on them on ebay.

98SuperchargedLs1

iTrader: (1)

if everything looks good then just do all the basic maintance to it before putting it in.

jeepnut24

That was my next question.... should I run synthetics or dino oil? What about the coolant? This is my first GM motor in a long time.


Thanks for the good news that 112K isn't that bad. It sounds like I should pull the pan, valve covers and intake, clean and replace.

What about the water pump? Should I replace it and the Tstat? I plan to tap the pump for the steam line anyway.

98SuperchargedLs1

iTrader: (1)

run synthetic oils, id also change everything you can while the motor is out, rear main seal even if it looks fine. if the motor is out it takes a few mins to do. and do all the seals, gaskets, waterpump, t-stat, plugs, wires etc. thats what i would do..

jeepnut24

How hard is the main seal to replace on one of these?

Bo185

I would replace the timing chain and oil pump if you have the money.

Don't **** with hte rear main if it aint leakng. Also alll the seals for the most part are reusable rubbber type!

jeepnut24

Isn't the front cover just as bad to replace as the rear main on these? I thought there was a $$$$ tool to line the front cover back up correctly?