Getting the drive train to the point where it is dependable and perfect is the first thing on the check list. How it looks is not as important at first, I just want to be able to drive it and know that under the hood and under the truck, everything is in perfect shape and I don’t have to worry about it.
In this Part 2 of our GMC Sierra Restomod Project which you can read about in Part 1 about how I purchased the truck, I tell you about the removal, rebuild and the reinstallation of the engine.
It did not begin that way though. Although it was my goal to rebuild the engine at some point, right now I just wanted to make it drive.
So the first thing I did is to start checking why the oil pressure is low when idling. I tried changing out the oil pressure sensor, but got no good results from it. The pressure was still low. The next item on the list to check is the oil filter and the oil pickup just in case something is lodged in there preventing oil from flowing freely.
The problem was that getting to the oil pickup requires to take half the engine apart. Not really but you can’t just remove the oil pan on these LS3’s. Once you remove it you also have to most times reset the rear main seal cover because the back 2 bolts on the oil pan screw into it and messing with it without resetting it is asking for leaks.
And of course to get to the rear main seal cover you have to remove the tranny and then you might as well replace the main seal. While you’re at it also replace the front main seal and the oil pump.
Ok so you get the picture. I did need to replace the oil pump for good measure with all the rest of the oil system components to really fix the oil pressure problem.
Basically I was at the point where I might as well get the engine out all the way and rebuild it completely for the effort I needed to put in to deal with the oil pressure problems.
Removing The Engine
Did I mention that I never rebuilt an engine before? Yeah, this was a scary project for me. Fortunately there is YouTube. And I found multiple videos of someone going in detail rebuilding one of these LS3’s. Thanks to them I was feeling a little bit of relief in believing that I can successfully complete this project.
I went and purchased an engine lift and an engine stand. I didn’t cheap out on them because my thinking is, it needs to have a good resale value so I can resell it after i’m done with them. All the cheapie engine lifts and stands on Marketplace don’t seem to be moving even thought they are priced so cheap, so I didn’t want to get my self into a position where I’ll be one of those competing with other “commodity” lifts and stands. I wanted to be able to offer a quality brand name tool.
When I started disconnecting all the electrical connectors, I put a piece of masking tape on each connector with a note on what it goes to. Every connector, every hose and bracket.
After disconnecting everything, it was time to unbolt all the bolts, the transmission, engine mounts and getting other things out of the way. Also fortunately because there was so much oil everywhere under the truck, every bolt came out with ease, even the exhaust header bolts that like to brake off on most old cars.
Getting the engine out was not that complicated. With the right tools, it is a breeze, even when working on it by my self.
Was I surprised at how filthy everything was in there? I can’t say I was. I expected filth and when I saw it I was glad I was rebuilding this thing.
New Parts And Engine Assembly
I must say it was pretty fun disassembling everything on the engine down to the last bolt. I had a box of parts that were going to be thrown away and replaced with new ones, a box of parts that needed to be cleaned and ziplock bags of bolts for each component labeled with a sharpie.
After calling several engine machining shops around town I kept getting great reviews about Gibson Performance in Spokane. After talking to Andrew, I realized why they all had such good things to say about him.
Thanks to Andrew at Gibson Performance in Spokane, WA, I was able to get the parts I needed and my anxiety of getting the wrong parts disappeared. Andrew walked me through everything I needed and offered me a package where he will purchase all the engine specific parts that will go with the specs of the engine and heads after they are machined.
I had Andrew hot tank all the parts to clean them all, machine the block and do a complete head job on both heads. He ordered all the parts for the heads and all the parts for the block. The only thing e did not get is the cam because I already bought that earlier from Texas Speed.
I saw a video about another GMC Sierra they put this cam into and I loved the sound it made so I ordered it for my self. It is a Stage III sloppy cam. See the photo in the slides for the exact specs.
When I got the parts back from Andrew, man oh man, they were beautiful! Just look at them in the photos below. It’s a new engine!
While I was cleaning the other parts like the alternator and brackets of all kinds, I got the transmission on the bench to clean. While on the bench, I went to roll it into a better position and the wheel got stuck in one of the concrete cracks in the floor and the tranny rolled off the back of the bench and slammed on the floor. It cracked in a bad way.. what a bummer.
Thankfully, my brother-in-law just had a similar one sitting in his shed, with low milage on it too. I picked it up from him for an amazing deal and I was back in business.
Engine Installation And Assembly
Installing the engine back into the truck was something I dreaded the entire summer and the day came when I just decided to do it and get it over with.
All those labels I stuck on all the connectors and hoses and all those labeled zip lock baggies of bolts came in so handy and made the assembly process sooo much easier.
I got the engine into the truck all by my self which was pretty cool, and it went a lot smoother than I expected. Just a few minutes and the engine was in.. I was like, “that’s it?”.
It took several days to get all the components and things hooked up.
The first start did not go without hick ups. I had a major leak from the fuel pressure regulator because I forgot to install an o-ring. It was missing and I was upsset. When I told my wife about it, she said “oh, I saw something like that on the ground by the truck”. I went quickly to look around the truck and to my surprise, there is was, laying by the truck staring at me.
With the o-ring back in the pressure regulator, I was able to start the truck, and it sounded amazing!! So loud, I think I woke most of my neighborhood. Yes, with open headers. No exhaust was installed yet. And the sloppy cam was doing it’s aggressive job, oh sooo good!
Until next time! Make sure to check out the Part 1 of the build here: Project Build: Truck Purchased and Part 3 here: Project Build: Cleaning Parts.
Valik loves tinkering in the garage and is currently restoring a 2000 GMC Sierra 1500 truck. He also writes about the progress on this blog. When not in the garage, Valik is also a web developer and a blogger. I know, strange, a hand in two completely different worlds. And that is the way he likes to keep it.
