My "cursed" engine rebuild

[Bondo07]

So background story. This is my $300 2002 trailblazer LTZ fully loaded power heated leather everything, bose 6 disc, sunroof, onstar, etc etc. And no thats not a typo, litterally picked it up for $300 with a bad transmission. Put the tranny out of my wrecked Silverado in it and drove it daily for like 6 months till it started knocking. I decided to do a full rebuild first of all, cuz I like doing it. It gains me experience, knowlege, and a great sense of accomplishment. Downside is a lighter wallet..... yea I'm about $1600+ into this rebuild.

Parts are hard to find and expensive. most recent setbacks is finding out rod bolts are torque to yeild, only place i could find them is gm parts direct. $96 with shipping, for 12 bolts.... Main cap bolts same deal, tty bolts. found them on rockauto, but then i didnt read fully that they only came with 10 bolts. You do the math. 6 cyl, 7 mains, 2 per main.... short version, back to rockauto and paid extra for overnight shipping so i can get this thing going.........

So i put the bottom end aside for another day and was about to put on the freshly remanned machined head from my 2006 parts truck (bigger valves, longer duration cam) and found out the head gasket was bent in the package. They used a box too small and folded it to fit in there... The machine shop that ordered it for me is trying their best to make it up to me even refunding me out of his own pocket... so another wait on parts that nobody ever has in stock anywhere... fml. On the bright side, I have 2 sets of head bolts now because I just know that one of those suckers is gonna snap on me I just know it. Luckily I only snapped 2 during removal, and also snapped 2 mains during removal and 1 while plastigaging. all came out fine with an easy out. Lucky.

Oh and I also broke my front diff housing and disconnect housing during removal. Lucky for me I bought a parts truck.

So in the meantime, I'm using the transmission/tcase out of the parts truck as well since I like 160k miles alot better than the 245k on my silverado trans. Sold alot of parts off the parts truck to make some of my money back, also using the parts to fix my Deer hit incident. So win win for me right? Working on pics right now

 

[Bondo07]

 

[Bondo07]

 

[Mooseman]

Nice pics. we haven't had too many of the guts of this engine before.

I think we've all been there with hang ups and delays for parts. During my used engine swap, both exhaust manifolds from the original and donor motors were cracked and getting it installed and working was a steep learning curve for me at the time.

 

[Bondo07]

Yea I've done my fair share of engine and tranny swaps as well as plenty of head gaskets and misc repairs. I've only done 1 complete rebuild prior to this though on a jeep 4.0 straight 6. One of the engine swaps was my friends envoy 4.2. Was the original reason I bought this truck. Got it for the engine and decided to keep it. So pulling this thing was familiar territory. Pulling it apart on the other hand was a learning adventure for sure. Only broke 2 head bolts! Pulling the engine out of my parts truck I actually was praying that they would snap. Sure enough. Snapped 11 out of 14 bolts. Made pulling it a lot easier. Just snap, pull the bolt out. Lol

 

[h82loseejr]

i swapped my engine also...got it out in about 12 or so hours and was in the garage about 11pm getting everything swapped to have new engine ready to drop in in the morning...was taking disconnect off and came in twice to double check forums that i was removing it correctly...had a chisel behind it and working on it for 15 min and then it started moving one more wack and i was just saying yyyyyyyyyyeeeeeeeeee.....and i looked nown it turned to yyyyyyyeeeeeeeeennnnnnnnnnnoooooooooooooooooooooooooooo....did same thing you did...these vehicles have to be the most frustrating to work on ever..i have so much money wraped up in mine..so i swapped motor it was supose to have 112000 on it and got it in and the thing smokes like crazy after idling for more than a couple min when its hot..other than that no smoke so my next "trailblazer project" is the valve seals gonna take whole day and maybe into next im sure

 

[mrrsm]

Welcome @Bondo07 … Thanks for sharing all the Tear Down images. I hope the New Head Bolts you chose are the updated FelPro Model# ES71334 flavor. Unless the machine shop is yet to recondition the Engine Block and/or lightly hone out the block and clean up the Crankshaft journals, etc… The Spun Bearing on the #1 Piston Con-Rod might mean it will need replacing. The Connecting Rod Inner Diameter tolerances are below...anything wider than these dimensions will guarantee another Spun Bearing:

Connecting Rod Bearing Bore Diameter: 2.3749-2.3755 inch

You know this already of course... but for others reading... AFAIK … the ‘cracked caps’ style of rod is not really amenable to having the End Caps ground off with a re-size honing being performed. So if you need a ready replacement Con-Rod…. There are a few Piston-Pin-&-Rod combos being sold individually on eBay that you can scavenge the Con-Rod from for your Re-Build:

http://www.ebay.com/itm/GM-4-2L-TRA...ash=item2cad9addd3:g:4fsAAOSw9eVXVzHk&vxp=mtr

 

[Matt]

I think 95% of us that have had to remove the disconnect have had the housing break...especially if it's seen any salt in winter.

 

[Bondo07]

Yea all the rods have already been re-rounded and oversize outside diameter bearings as well as underside inside diameter. Rods, crank, and head are all gone through by the machine shop. I'm not touching the block. That's one thing he said is if there is no reason to hone the cylinders just leave them alone. Main bearings were just fine too so no worries there. At the moment its half put back together with new rings and bearings. I didn't take any pics of the machined rods or crank like I should have.

But I'm waiting on the head gasket, rod bolts, and main bolts before I can go any farther.

Trans and tcase from the parts truck are up and mounted, just need to connect lines and rear driveshaft, drop the pan and change filter. Also fiddling with other stuff while I'm at it. Cv shafts and spindles with good upper ball joints off the parts truck, mine were going out. New wheel hubs. Front diff cover swapped to fix my broken one, actuator and disconnect off the parts truck as well. Probably gonna eventually take the tailgate too but I need to paint it.

 

[mrrsm]

When the Machinist suggested leaving the Cylinder Bores alone... was it because you are NOT using the Original Pistons with Original Rings... or would that also apply to replacing them with a Stock Set of Pistons and New Moly-Rings? The reason I ask is that I'm in the middle of an "Ancient Re-Build" myself...and I'm getting close to pulling out the bottom end as well. I have New Mahle Stock Pistons (Rings are Pending) So If I don't have to even perform a light hone with a 600 Grit Flex-Hone to remove the scuffing inside...then so much the better. Thanks in advance for a detailed clarification.

 

[Bondo07]

His reasoning is miles of wear on the cylinder walls leaves an almost perfectly smooth bore. If there is no scuffs or scratches to remove, leave well enough alone. Im using the same pistons that came out of the engine, but he said that doesn't matter weather they are old or new. He also said something about getting just moly rings, not chromoly or whatever else is out there.

My main crank bolts just arrived so I can do something. New head gasket should be at the parts store in an hour or so.

 

[Bondo07]

Sorry if thats a bit vague. but no its not because of the pistons im using. As long as your new pistons are stock size, and the cylinder walls are clean with no scuffs or scratches, i'd leave them be.

 

[Bondo07]

Top bolt is standard head bolt for 02, bottom one is "updated design" from fram I got from Rockauto





Timed!

 

[Bondo07]

Making progress. Decided the corroded aluminum valve cover was too ugly, so some work with a grinder with a cup brush and polishing wheel, some engine enamel, and I think it looks a lot better now.

 

[Mooseman]

Valve cover is aluminum? Never seen one of those before. All others have been composite fiberglass. But then, you have an early version of this engine with the balancer with that ring in front of it, which necessitated a special puller.

 

[Bondo07]

The valve cover is the 06 came with the 06 head off my parts truck. But another question... The 06 head has a coolant temp sensor on the rear passenger side of the head. The 02 does not. Can I just put the sensor in and cut the wires? Or is there something I'm missing. 02 has a sensor by the thermostat on the block, not sure about the 06 block

 

[Mooseman]

Yeah, they moved the temp sensor to the head in '06 so yeah, leave it in the head and snip off the wires.

Forgot you were swapping in an '06 head.

 

[Bondo07]

Thanks

 

[mrrsm]

@Bondo07 ... When the time comes to install your Motor... if it's not too much of a distraction... would take some 'Staged' images at the key points of buttoning it up? IIANM ...No one has actually documented that process yet... and the speed of your R&R of this Engine is remarkable to those of us who cannot move our projects along as quickly... so that last part would be very helpful.

 

[Bondo07]

Thanks. Ill try to remember to take as many pics as I can. Maybe ill set up a camera and do a time lapse or something, but probably not. Lol. I'm still waiting on the rod bolts as of right now. The only reason the oil pan isn't on yet.

Broke off 2 studs for the exhaust manifold heat shield, so I said bye bye to it, ground down the other studs, ground off the casting numbers, and painted it flat black with high heat exhaust paint. Now I can't get the old o2 sensor out of my old manifold so I might just break down and buy a new one of those too.

 

[Mooseman]

A new O2 sensor is never a bad idea.

 

[mrrsm]

I was thinking about the problem of removing the insulating Exhaust Manifold Shield and the concerns I have about doing that are worth mentioning. Unlike Conducted or Convected Heat Energy, such as that being blown away by the motion of Ambient Air through the Radiator... just like the feeling of heat you can feel when facing the Sun on a windy day... Radiant Heat Energy is NOT affected by the motion of air around the engine. This means that over time... things in the path of this Radiant Energy can be directly heated up to higher temperatures than you might imagine... and that added heat can affect anything exposed to it... especially anything flammable or metallic within its Radiant Path.

Thus... Rubber and Plastic Hosing and containers and piping items made of Nylon or Plastic can either be softened or even melted from such direct exposure. In some case where such things are being heated over very long periods, such as on long drives or when traveling, the Exhaust Manifold can get hot enough to become incandescent and glow with enough energy to set things on fire. In the case of Off Road excursions... driving without an Exhaust Manifold Heat Shield can expose tall grass to direct contact with the Exhaust Manifold and set it on fire inside the Engine Compartment. So perhaps by using 1" Fiberglas header Wrap and Stainless Steel "Zip-Ties" ...you could augment the temporary coating of High Temperature Paint and solve the problem.

 

[Bondo07]

I've been thinking about this too. I'm going to invest in some header wrap when the funds are available, but as of right now I'm most concerned about finishing this project. Removing the exhaust manifold in the near future won't be as bad as first removing it with all the rusted tight bolts breaking off on me. Thanks for the concern. Got any links to decent exhaust wrap? Think local parts store would carry it on hand?

 

[Mooseman]

Local parts stores would be more expensive. Look at Amazon, eBay. Speaking of which:
https://www.amazon.com/dp/B012C5FOLK/?tag=gmtnation-20

http://www.ebay.ca/itm/2-50Ft-Roll-...ash=item1c4b404a08:g:6ksAAOSw2gxYwPXq&vxp=mtr

BUT, my concern is that wrapping the manifold completely around each "tube" would retain too much heat inside the manifold and cause it to crack or fail. This has been a concern with those wrapping headers. This is probably why OEM's don't do this neither, which initially would make sense to reduce underhood temps. Instead, I would source a "blanket" type heat barrier like this or header wrap on the manifold in a similar. Even then, given the tendency of this manifold to crack if you even look at it funny, I'd try to figure something that would allow a maximum of air circulation.

 

[mrrsm]

Sure... Since you are only dealing with "One Side"... a 2"W X 25'L Roll of the stuff with a few bags full of Stainless Steel Zip-Ties available at Harbor Freight would not be that expensive to obtain. You can see what is offered below on the Amazon DuckDuckGo search for examples of a wide range of width, thickness layers, roll lengths as well as Colors, too ... if that would be important (Orange Colored Header Wrap would certainly set off your newly painted Orange Valve Cover... ;>)

Have a look at these images for the links to Product Names, Pricing and Availability:

https://duckduckgo.com/?q=amazon+exhaust+header+wrap&t=ha&atb=v41-7a_&iax=1&ia=images

You already know this but JIK... A few words to the wise though about working with this "very friable stuff"...

Wear Mechanic's Gloves and throw on some Old Clothes with a long sleeved shirt... as many particles of Fiber-Glas will be falling off or getting blown around you and into the air while you work and these can quite easily getting embedded into everything. You don't want to feel "itchy" for weeks on end or transfer this junk by accident onto your family members... so don't carry the particles on your "work clothing" or skin back inside the house. Don't eat or handle food until you are done with this job and put away this toxic junk in a plastic bag afterwards. Breathing in non-biodegradable fibers of Fiber-Glas can cause lung irritation or worse... Mesothelioma ...so wearing a paper Paint Face Mask is not a bad idea.

Try to figure out exactly what your wrapping strategy is going to be by using a length of the White Cotton Clothesline Rope you can buy at HF and practice with it before hand to find the best way to install the stuff. It can become a nightmare of losing control of a fully unwrapped roll of this stuff ...so avoid doing the work in the house. You will need to know where to start with an anchor point for your initial wrapping and then fasten it tightly with the S/S Zip-Ties.

Angle Cutting Metal Shears work best for snipping off the loose ends. If necessary... use two S/S Zip-Ties together to reach around the wider parts of the Exhaust Manifold. You will also need a pair of Industrial Strength Scissors to cut off the last unnecessary length of wrap as putting on too much wrap is just as bad as putting on too little. Don't pre-cut the wrap... if you're lucky...one roll be either more than you need... or "wind" up being just enough. They sell High Temp Paint that can be sprayed over the Fiber-Glas Wrap to harden and encase everything and keep the Fiber-Glas wrap from "un-wrapping" from constant Engine Vibrations and also using many S/S Zip-Ties to thoroughly secure the wrap will do the trick. So... I guess that's a 'Wrap'. ;>)

 

[Bondo07]

MY ROD BOLTS HAVE ARRIVED!!! Got them in and torqued to spec. Oil pan is on. Didn't buy enough wrap so my exhaust manifold is only partially wrapped. I got around the runners at least, to the point I can bolt it on and ill wrap the rest tomorrow.

 

[Tiggerr]

Need some paint on the rest of that engine! No better time to pretty it up.....

 

[Bondo07]

Thought about it. I would have to go buy some more. What you think? Should I just do the whole engine chevy orange?

 

[Tiggerr]

May as well. Or do the block/head black or aluminum with the orange as accent

 

[Bondo07]

Didn't do any more beautifying on the engine. Didn't wanna waste time. Also found out the 06 doesn't have a fuel pressure regulator on the rail so the bolt for mine hit the valve cover and injectors wouldn't seat right. So trimmed it with a cut off wheel and it fit. The engine is almost where its gotta be, but the bellhousing and driver side mount won't seat right. Called it a night.







This is the seal advanced auto sold me... Looks small.










Found out my cooler line broke so I patched it with the 90 I had off my old silverado and some hose and clamps. Hope it holds.






This is what's giving me grief

 

[m.mcmillen]

The seal that you're looking for will look like this

The Napa part number is 15618. Either Napa or the dealership should have them in stock.

 

[mrrsm]

...about the "Thing" that is giving you a problem... under the hood at the Driver's side of the Engine Bay... But did you mean there is a problem with the Starter Wiring? Here is a generic look at look at what it should look like ...before being "undone":

Forgive me being such a stickler for surgical cleanliness on engine interiors... but after seeing the black lacquer covering your Oil Pump Pick Up Tube... I was wondering why you avoided cleaning it ...and the bottom of the Crank-Case Oil Pan of the Old Oil? I've been chastised on more than one occasion for trying to "Separate Fly-Sh*t from Pepper" so if you think the question impertinent... feel free to take a swing at my chin.

If I didn't make certain that my Engine Crankcase was Sparkling Clean down in there before inverting the block and buttoning up the bottom... THIS Thing would crawl out from the Mung underneath the Wind-age Tray ...and after drinking all of my Break-In Oil...it would Eat the Entire Bottom End out of my Engine:




The other questions I have relates to the technique you followed to guide the Engine Block onto the 4L60E Guide Pins and from what direction you were able to access to and tighten down the various 11 Transmission Case Bolts. Did you follow @Mooseman 's approach of waiting to install the Motor Mounts until you got the Top Bolts started? And did you also have to loosen one side of the Transmission Mount Cross Member to help gain access in this manner?

 

[therealsethallen]

The seal that you're looking for will look like this
View attachment 80343
The Napa part number is 15618. Either Napa or the dealership should have them in stock.

The National Bearing Number for that part is 710687, my OEM GM one from Amazon was 19257296

 

[Bondo07]

No the starter wiring is fine. All the wiring I have a handle on pretty well. The motor mount won't sit in all the way because its not aligned with the dowels on the tranny bellhousing. I have a feeling the torque converter isn't seated all the way so ill probably end up dropping the crossmember again anyway. The process? Well I had the upper mounts bolted to the block already, the drivers side mount was removed while pulling the engine to clear the diff, and I reinstalled it after the diff cleared when lowering the engine back in. Forgive me for not being ocd about cleanliness, but my backup car is on its last leg and I'm worried about being without a vehicle again. So time is of the essence, so to speak. By the way MRRSM, I just wanna compliment you in your way with words. Its very poetic I think. Refreshing really.

Anyways, I'm on my way home now to try to button this thing up. Need to drop the tranny pan and change oil and filter, install driveshaft and all the wiring, and hopefully get this thing fired up tonight.

 

[mrrsm]

Please do not mistake my concern for a happy outcome for you as criticism. I very much appreciate such comments, Brother. And while it is not the first time a Member has mentioned something similar after taking glances at my writing with friendly eyes ... based upon their "immediate need to know just the facts..." at the heart of solving mechanical problems here at GMT Nation... Many more Members would argue that my explanations would benefit from having "More Meat... Less Art" as mentioned in The Bard's play, 'Hamlet' ...and that I would be ever so much better at it, if only so many of my words ...did not get in the way. ;-)

 

[Bondo07]

This is how I lined up the bellhousing. Worked like a charm.


Accessories are getting there




I returned the wrong seal, ordered the proper one. Should be here wed. Won't have time to work on it till Friday since spring break is over. Yes, I'm going to school for welding. On my 2nd year and almost done. Full time school fulltime work, no time for anything else...

 

[Bondo07]

Update! Still working on it. New front left axle seal is in. New sway bar links, new wheel hubs, spindles off my parts truck (ball joints are way better than mine) new brake pads, whole front suspension is assembled and wheels are now on the ground! Feels good. Everything on the underside is assembled. Just buttoning everything up now. Radiator, a.c., oil, trans fluid, etc etc. Need a new belt tensioner in the near future but I gotta get this running first. Easy fix for later on. Now to my question. Best way to "prime" the oil pump? I pulled the plug by the oil pressure sending unit and dumped as much oil as I could down there. Filled up the filter too till the bubbles stopped.

 

[Mooseman]

FWIW, I didn't prime mine when I swapped in a used engine but you rebuilt yours so, not a bad idea to prime it.

Unless you get a full blown pressurized primer that you will only use once in your life, not too many ways to fully pressurize the system. I would use this same method as this one for LS engines to fill the oil pump at least. Use the oil pressure sensor port.

 

[Bondo07]

Ok yea I did that much. I didn't quite wait the 3 minutes he said, but no more oil was going in

 

[mrrsm]

This is going to sound crazy coming from someone who put in an awful lot of time creating a very sophisticated Pre-Oiler... But I'd bet that you could get away with using a Small Plastic Insecticide Sprayer... a length of 3/8" Fuel Line and after filling it with a few quarts of Break-in Oil ...just Hand Pump the stuff in there... Not complicated...and Not expensive on the hardware side. ;-)