Ask for references of previous engine rebuilds and customers. Your iron block LM7 could possibly have enough metal meat in the cylinder walls to bore and rebuild as a 5.7 liter engine if you are interested.

You don't mention your engine's mileage but I would insist that the heads get rebuilt if over 150,000 miles - 3-angle valve seat cuts, new valves and valve seals.

Consider asking for a new crank position sensor, knock sensors and camshaft position sensor. These are easy to replace now, harder later.

New water pump??

Rick

 

Quick question, are you rebuilding to get more power or are you rebuilding just to rebuild? If you are not rebuilding to cam it and put some extra fun stuff on it such as turning it into a 5.7 as stated above or a stroker motor then don't do it, better to just go pick up a used engine and just swap it out, it will be way cheaper.

In my opinion just take the heads to a machinist and ask if they are still worthy of getting put back on the engine if they are then slap them back on.

Just my $.02

 

I would need someone to rebuild it and keep it stock. I'm not wanting to add any extras or turn it into a 5.7. I just want a daily driver like it is right now.

I just have a few bolt on's right now and a blackbear 87 tune.

The engine has 148k on it. I replaced the oil pump and pick up tube o-ring a few months ago hoping it could pedal it along but the oil pressure has become worse quickly.

I don't have the facility's or tools to pull my current engine an put a used one in. Who would I need to take the truck to inorder to have a used engine put in? I don't know if the engine rebuilder I visited yesterday would help me find a used 5.3 and install it.

If I were able to find a used 5.3, can I use the same computer that's in the truck or would I have to get a different computer or would a used engine come with a computer?

 

All I can say is I have 06 silverado and it's just turned over 370,000 miles still going but I'm about to do a build.

 

yours is too new to use the earlier 24 tooth reluctor wheel I believe.
Maybe some guys here could guide you on that.
What area are you in maybe a member is in your area who can help you out. If you didnt toally lose oil pressure check a bearing or two it may be fine. 148k isnt much for those engines.

 

I think the minimum acceptable oil pressure at idle on my 5.3 is 8 PSI. Currently at idle right now I'm getting 10 psi on my mechanical oil gauge. To me that's very close to the minimum oil pressure.

Right now I'm not getting any ticking or tapping from oil starvation. I put some 10w-40 oil in it to see if that would bring up the pressure but I still get the same result.

When driving at 2k rpm, if I'm on the accelerator the pressure will drop 5 psi then when I let off the accelerator the psi will go back up 5 psi. If the engine is revved over 4K rpm, the psi does not go above 40.

Don't you have to remove the engine to check the CAM bearings? When I had the pan dropped, nothing looked out of the ordinary on a 148k mile motor.

I know that getting a rebuild kit will have the cam bearings but other than that, I'm confused on what else gets replaced with a engine rebuild.

Do head get replaced? Do lifters and cam get replaced on a rebuild? Does the crank get replaced? Or is it a situation if all of those parts are good, then they don't get replaced.

I've got a message out to the engine rebuilder I talked to yesterday to see what exact parts are replaced on the rebuild and if there are any other cheaper options.

I'm in Oklahoma City, there are a few salvage yards in the area, I could call them to see if they have any 5.3s but again I don't have the capability to pull and install an engine.

 

That shop should be able to install a used 5.3, most shops should be able to do that. Trust me it will be so much cheaper than paying almost 5 grand for a rebuild.

 

Ok. Obviously with an engine rebuild I can keep the ECU thas in my truck right now.

If I were to get a used 5.3 installed, would I be able to use the ECU that is in my truck now or will the used engine come with the ECU that belongs to that engine?

 

You will use the same ECU

 

Try this site...Free shipping!!!

https://sdparts.com/c-1105381-engine-tr ... ement.html

 

Hot damn there you go!

 

I talked to a few other mechanic shops today. Both suggested that the screen below the oil pressure sensor at the top of the engine could be clogged.......however the 2005 does not have that screen and I have replace the oil pressure sensor 2 times so far.

The last shop I talked to quoted me $4800 for a new engine that has all new internals and heads. Would use the intake, fuel rails, alternator, exhaust manifolds off my current engine to put on the new one. I asked them about finding a salvage yard engine, said they tend to shy away from those cause they have had a few bad ones before. I told him my oil pressure situation and he said 8-10 psi is with in spec at idle.

I called a salvage yard that mainly deals with GM. They found a 5.3l with 80k miles for $1675. The engine is out of state and would have to be shipped to my location. Then I got quoted 900-1000 bucks to have it installed by a shop.

Decisions decisions. Since I'm not getting any ticking or tapping noise with 10w-40 synthetic oil and a wix filter and bearly with in spec oil pressure, would you drive it until it completely goes out?

The salvage engine sounds good but with it being in another state and having no idea what condition it's in, I'm very hesitant to go that route. But almost 5k on an engine rebuild/new engine is a bit much.

 

Now you just have to think about your truck I guess, do you plan on keeping it for years and years then I guess maybe the entire rebuild is worth it. If you don't think you are going to keep it forever then just do the salvage yard. Personally I would just do the salvage yard no matter what.

 

If you're keeping the truck, I recommend a purchase from the link I provided earlier, have it shipped to the shop of your choice, and have them install it. You'll be considerably under $4K with a guarantee.

 

I recently acquired 2 5.3l engines. 1 aluminum block and 1 cast iron block. Paying someone to rebuild them is stupid expensive. The $4,000 est you received is in the ballpark. Keep in mind they are going to do every measurement and service they can. That drives the price through the roof. Straight cost on gaskets, bolts, bearings, and all the other crap is in the area of $1,500. They will typically not warranty the work they do past it starting and running. This is not a race engine. Don't pay to have it assembled like one. Get a rebuilt engine from a decent source or take your chances with a junk yard hero.

 

I understand your oil pressure concerns.

I think you are prematurely chasing the problem. No noise, no running issues, no debris in the oil pan.

Keep on driving it. It may surprise you and be 10s of thousands of miles away from failure or rebuild. 250K with any half way decent oil change history is pretty common on these engines.

Like others have said, I think you and your wallet would be better served with a lower mileage salvage yard engine or a reman from a dedicated and respected rebuilder. I have heard good things about Jasper Rebuilt engines and have always thought they would be my first stop for a quality stock reman engine.

 

I completely agree with sgjii. There doesn't seem to be enough evidence to warrant an engine rebuild or replace. More diagnosis is needed to determine what your actual oil pump pressure output is. Dash gauges can be inaccurate. You could possibly be looking at just an oil pump or bypass problem which should be much cheaper to repair. I would have the oil pump pressure checked with a calibrated gauge. If that checks okay, I'd drive it and just keep an eye on things.

I have 250k miles on my 2010 5.3 Z71 and it still runs very strong. I have never babied it... I drive it hard. During those miles I have only replaced the oil pressure sender, throttle body, and belt tensioner. No other repairs, only maintenance. Oil pressure has been consistent at 10 psi @ idle... +/- 40 psi @ cruising. But I have always changed the oil and filter religiously with full synthetic. I am super satisfied with the performance and longevity of this truck.

A few smaller issues I have...
It has recently begun to leak some oil at the rear main seal area, and I'm getting a misfire every 6 months or so due to ash build up on a few spark plugs so it is beginning to burn oil. Also like most of these engines, it does have the occasional lifter tick, but no other issues. Incidentally, I have found that if I change the oil and filter at shorter intervals the engine tick shows up much less frequently.