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TrailblazerSS 2007
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Discussion Starter #1
So I spent the majority of my evening sifting through all the info on this site regarding the issues with engine oiling/rod knocks etc. Most of what I see are guys that have work done and have spent time at the track. My motor is stock with 145k intake/exhaust/tune. Never been to the track, but has been driven hard. Since it has gotten really hot here I have noticed a knock (not loud, no power loss) at idle when the engine is warmed up. I know our oil pressure gauges are not exactly accurate. So I checked this the scanner this morning and its sitting at 16psi. Identifix info states the min hot idle spec is only 6psi. That is a scary number. I changed the oil yesterday and didn't see any metal in the oil, but I am getting very concerned at this point. I am assuming I am looking at a rebuild, but I'm nervous because I am also sitting on a stock original transmission. Now all that being said, just trying to get out of my own head and get some opinions on my next step. I do not have a lot of money to spend and this is my daily driver. The good news is I am able to do the work myself to keep costs down.. :dunno:
 

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I just pulled my motor for a knock and to do the oil pickup mod.

Even with doing the R&R on my own, the motor work is going to be at least $3000. That's for freshening the long block and re-using my crank and rods while adding a custom cam and springs/LS7 lifters. My issue ended up being the #1 piston skirts being banged up in the bore and i'm using my favor list up at the machine shop. Things like seals, bearings, gaskets, lifters, new rockers, pushrods, timing set, and machine work add up really fast and you need to freshen it all at your mileage most likely.

Are you AWD? That will to add cost as well. My front carrier needs rebuilt at only 75k and it's a good idea to do axle seals at your mileage and do the diff pinion seal.

I see you are in jersey also so if any road salt got to things like trans and power steering lines, those need done while it's out like mine.
 

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TrailblazerSS 2007
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Discussion Starter #3
I just pulled my motor for a knock and to do the oil pickup mod.

Even with doing the R&R on my own, the motor work is going to be at least $3000. That's for freshening the long block and re-using my crank and rods while adding a custom cam and springs/LS7 lifters. My issue ended up being the #1 piston skirts being banged up in the bore and i'm using my favor list up at the machine shop. Things like seals, bearings, gaskets, lifters, new rockers, pushrods, timing set, and machine work add up really fast and you need to freshen it all at your mileage most likely.

Are you AWD? That will to add cost as well. My front carrier needs rebuilt at only 75k and it's a good idea to do axle seals at your mileage and do the diff pinion seal.

I see you are in jersey also so if any road salt got to things like trans and power steering lines, those need done while it's out like mine.


Lol yea I am in jersey, luckily the truck has been garage kept for most of its life so I am not too concerned with any rusty line issues so I'm gonna dodge a bullet there. I am AWD, and I know that if I am pulling the motor I am rebuilding the diff because it is leaking. (removed and rebuilt once already but that damn leak keeps coming back) I certainly want to do things only once and correctly. I was debating if I needed to even do anything with the top end. (I want to for the fun stuff) but idk if its truly necessary. Where did you track all your parts down?
 

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Lol yea I am in jersey, luckily the truck has been garage kept for most of its life so I am not too concerned with any rusty line issues so I'm gonna dodge a bullet there. I am AWD, and I know that if I am pulling the motor I am rebuilding the diff because it is leaking. (removed and rebuilt once already but that damn leak keeps coming back) I certainly want to do things only once and correctly. I was debating if I needed to even do anything with the top end. (I want to for the fun stuff) but idk if its truly necessary. Where did you track all your parts down?
All the motor internals will be sourced by the engine builder since they buy direct from dealers.

The LS7 lifters are a must for peace of mind IMO but everything else can be stock. I need pushrods and rockers because they are worn..I was suggesting yours probably will be as well but only one way to find out. I'm doing new springs to support a bigger cam in the future but everything else is basic...no need for a forged bottom end for me.

One thing to keep in mind that a few of us ran into recently is that if it needs honed at all, you can only go +.005 and need to get forged pistons at that point in the rebuild.
 

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If you need it done quick, that's when most go with a shortblock then sell off their used motor as-is to recoup some of the cost. I see a few suppliers mentioned fequently on here but I've never used them and I have a builder that I trust more.
 

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Discussion Starter #6
I actually run an auto repair shop so I was thinking I might be able to save on the parts by purchasing them through the business and just handing everything over to the machine shop to finish the bottom end. Just didn't know if there were any aftermarket suppliers for the bearings and whatnot that are better quality then factory but still keeping it stock if you know what I mean lol. Thanks for your input. I am still really on the fence about whether or not it worth all that needs to be done.
 

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I'm sorry to hear that, it sounds like your number is up :(

The factory LS internals are actually great... the oil starvation problem would do a number on any bottom end, aftermarket or not. So as long as you fix that with a pickup tube, I would be totally find rebuilding with stock components. Good luck with the repair! Low oil pressure is not a fun thing to see on the gauge.
 

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TrailblazerSS 2007
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Discussion Starter #8
All the motor internals will be sourced by the engine builder since they buy direct from dealers.

The LS7 lifters are a must for peace of mind IMO but everything else can be stock. I need pushrods and rockers because they are worn..I was suggesting yours probably will be as well but only one way to find out. I'm doing new springs to support a bigger cam in the future but everything else is basic...no need for a forged bottom end for me.

One thing to keep in mind that a few of us ran into recently is that if it needs honed at all, you can only go +.005 and need to get forged pistons at that point in the rebuild.
How much did you end up paying for the lifters? That's gonna be expensive on its own.
 

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Discussion Starter #9
I'm sorry to hear that, it sounds like your number is up :(

The factory LS internals are actually great... the oil starvation problem would do a number on any bottom end, aftermarket or not. So as long as you fix that with a pickup tube, I would be totally find rebuilding with stock components. Good luck with the repair! Low oil pressure is not a fun thing to see on the gauge.
Thanks!!
I am still weighing my options on whether or not to add in the fun stuff or stick with a stock repair. I will definitely be purchasing your oil pick up tube and most likely your efan set up.
 

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How much did you end up paying for the lifters? That's gonna be expensive on its own.

They were 125. Cheap. Rockers are 10 each and cheap also. Nothing fancy. The cam, pistons, and springs are what added up fast for me. I had no choice and had to get forged pistons to use my block since the bores needed cleaned up.
 
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