larrybud

Hello all. I'm new here. I have a 2000 Suburban with what i now know to be an LM7. That's the 5.3L with a T in the 8th position of the VIN as I'm sure most of you know. Almost exactly 1 year ago, while pulling a horse trailer I had purchased home, my oil pump went out. I had all the warning signs but didn't heed them. I drove the motor too long and trashed it. At this point, it was 14 years old, so I bought my wife a new Burb and put that one in the pasture.
My daughter will start driving soon so I am planning on getting it running again. I am leaning towards buying a used motor, replacing everything I can get to easily and installing it. I have not ruled out rebuilding the one I have but I don't think at this point that i will go that route.
One of the problems when my wife was driving it previously was that it would lose coolant. I tried putting pressure in the system to try to find the leak. I replaced the intake gaskets per advice. changed all the hoses, radiator cap and everything else short of pulling the heads to try to resolve the problem. No dice, I never could find the source of the leak so I just put a quart of so in every so often.
I noticed that this seems to be a common problem on this motor and was hoping that maybe someone could offer some advise on what the problem may be so that i might be able to take some preventative action on this new motor to keep this from happening.
Also, I would accept any sage advice that's out there regarding this swap.

Thanks

Paul Bell

iTrader: (9)

Welcome to LS1tech!

I'd prefer to rebuild the engine. You know it's right and all new. With a used engine, you really don't know what you'll get. It's a lot of work to install an engine only to find out six months later it's a junk motor.

Coolant leaks can be anything. If you did all that work and you haven't found it yet, you've missed the cause. Sometimes it's simply a cracked overflow bottle.

larrybud

Thanks. What's a ballpark for a stock rebuild. I've seen the rebuild kits for around $500.

mahone30

iTrader: (3)

500 for a rebuild sounds awful cheap. you must just be talking parts? If you're doing it yourself, have at it!

larrybud

Yes. I saw a full rebuild kit on summit for around $500. The machine shop that I use is closed for retooling until sometime in May. Just curious what I might expect to pay for a bore and a grind, etc.

Paul Bell

iTrader: (9)

I believe block work such as tank cleaning, bore & hone, cam bearings, fitting a cam might be about $500.00, parts not included. Pistons should come with rings, they'll need them to press them onto your rods. Must give cam so they can fit to block.

Zmg00camaross

iTrader: (11)

Where are you located at? Rebuilding can start getting expensive. New bearings,rods,pistons and rings,timing chain etc, a used engine from a reputable place isn't a terrible idea and most give you a little warranty. Also can find a new long block and just get it all new. Depends on budget and if you or a shop is doing the repairs.

k24556

Sounds like your leak may be at the two places you didn't check:

Heater core connections

Water pump gaskets, or leaking front seal.

If you smell antifreeze in the cabin = heater core

If the water pump gaskets you may not see a leak. Sometimes the heat of the engine causes the coolant to evaporate before you see the sign of a puddle.

There are lots of 5.3's out there and I've had pretty good luck with used ones putting them in something as old as that. That might be the most economical choice. Besides, young adult drivers usually destroy their first car out of total ignorance. Putting a new crate engine, or a good rebuilt might be like lipstick on a pig (I am not insulting you, so please don't take offense, I know what lots of trailering does to a vehicle, there is more worn stuff than just the engine).

larrybud

No offense taken. There is also a possibility that I fix this and sell it and put it towards a pickup which makes buying used even more desirable. Well, i got my open for a motor so we'll see what turns up. Thanks for the advice all. I'll update when i get more info.