Engine replacement

xxxotiknightz

Original poster
Member
Dec 8, 2011
22
has anyone ever replaced the engine in a v8 envoy or trailblazer?? My denali has spun a bearing and needs replacement. The local shops are quoting between 4-7k for the replacement. Any help is welcome.
 

Jkust

Member
Dec 4, 2011
946
xxxotiknightz said:
has anyone ever replaced the engine in a v8 envoy or trailblazer?? My denali has spun a bearing and needs replacement. The local shops are quoting between 4-7k for the replacement. Any help is welcome.

Is that for a brand new crate engine with warranty? How many miles are on your wrecked engine?
 

ScarabEpic22

Member
Nov 20, 2011
728
Figure about half of that is labor, sounds like a rebuilt engine to me. I think new I6s go for 4-5k, 5.3s (especially ours being all aluminum) are going to be more than that. Id have it bored to 6.0L and have a sleeper Denali, being 2WD I bet mileage wont take too much of a hit. Would lose DOD/AFM though.

eBay doesnt have any 5.3s that have lower miles, although you could buy a wrecked Saab 9-7X 5.3 for 2k and pull the engine from it. Has 184k so not sure Id recommend that.
 

xxxotiknightz

Original poster
Member
Dec 8, 2011
22
the lowest one was for an engine with 67k miles on it and they said 3900 plus tax. The others are for remanned and new crate motors. A couple of the guys I talked to said that the computer was telling them to charge for 20 hrs. in labor. One guy even said that was about double the usual amount. Im not 100% sure but the dealership told me that I had spun bearings and the engine needed replacement. Ive spun bearings before and it never sounded quite like this. The sound is a loud hard tapping sound with a random squeal here and there. The idle is a bit rough as well. And the quotes were for the new engine and installation
 

jimmyjam

Member
Nov 18, 2011
1,634
shop around. look for places that do rebuilds. i paid $3k total for a replacement crank, rod, bearings, gaskets, rebuilt heads while they were in there

swapping an engine isn't that big of an ordeal, especially if its 2wd. if people are charging you that much its because they aren't really interested in the job.
 

n0kfb

Member
Dec 8, 2011
104
I'd be tempted to get a second opinion.

Where is the squealing noise coming from? If it is from the front of the engine it might be something cheap - like an idler pulley or tensioner pulley. As for the knock, who knows. Replacing the main and rod bearings shouldn't cost as much as a replacement engine.

-- Dan Meyer :coffee:
 

gmcman

Member
Dec 12, 2011
4,659
Is the sound a tap or a thunk? Did you pull the serpentine belt and see if the noise went away? Just curious.

Pull the drain plug and see if metal shavings come out. I wish there was a way to pull the trans, drop the pan and crank, then change out all the bearings but if you spun a rod bearing, chances are you boogered up the rod and you need to pull the head to get it out.

Engines aren't hard to rebuild, just need alot of ziploc bags and some patience. If it were mine, I would save your $$$ and rebuild it myself if that's what needs to be done.
 

xxxotiknightz

Original poster
Member
Dec 8, 2011
22
Its more of a loud tap. but would that be because of the aluminum block? Also, would a spun bearing cause stumbling idle? I noticed the tapping last sunday when it was really lite, and the dipstick read full. My wife and I drove it to the dealership approx. 30 miles, the tapping went from a quiet annoying tap to a loud annoying tap for the last mile or so. When they dipped the oil at the dealer the stick was dry. We had it towed back so as not to hurt the engine more. The dealer suggested replacing the engine.
 

dcrews

Member
Dec 4, 2011
4
Collapsed lifter?

Do a compression test and get back to us..

I've seen a LOT LOT LOT of these engines have lifter problems and they will make a loud-ish tap sound and an engine stumble...

GENERALLY speaking, a spun bearing will not make the engine run bad. It will just lose oil pressure and make noise.
 

xxxotiknightz

Original poster
Member
Dec 8, 2011
22
looks like it may be both. I drained the oil today and there were plenty of fresh shavings, and only about half the oil that should have been in it. What i cant figure out is where it went. There are no signs of a leak anywhere that I can find. No oil on the block, no oil on the bottom. Not even a spot on the parking spot at work and home. I dont have the stuff for a compression test on hand. I may go to the base garage and see if they have one.
 

jimmyjam

Member
Nov 18, 2011
1,634
xxxotiknightz said:
What i cant figure out is where it went. There are no signs of a leak anywhere that I can find. No oil on the block, no oil on the bottom. Not even a spot on the parking spot at work and home.
exact same thing happened to me... :frown: i feel(felt) your pain
 

TGFB87

Member
Dec 27, 2011
14
Im going through this right now myself.

Found that coolant got mixed with the oil one morning. Start it up - got a good knocking going on as I lightly accelerate.

Bought a brand new crate engine from a Chevy dealer near St. Louis. $2750 shipped to my door + $300 core. (NW Indiana.)
$400 for Water pump, gaskets, and plugs.
Approx $2000 for labor. I guess its a lot of dismantlement because its 4WD.

So, not including the core, Im in this for just a shade over $5100.

Good news is that the new motor comes with a 3yr/100K mile warranty from GM.

As to the failure of the orig. engine... I may discuss that in a different thread. But it is related to a somewhat known casting issue with the heads on 5.3's built between a certain time frame. I will have to dig up the info and post it here as this info was pretty much what caused me to stray away from the idea of a used engine.
 

xxxotiknightz

Original poster
Member
Dec 8, 2011
22
Well, im taking the Denali home to Tennessee to my old mechanic. He's putting a new engine in w/ 5yr- 100k mile warranty. $5000 bought and installed.
 

Jkust

Member
Dec 4, 2011
946
Sorry to hear that.
 

Black_tb

Member
Dec 6, 2011
817
if the vehicle is payed for and your out only 5 grand and you have a 5 year warranty that isn't terrible considering what a whole new vehicle would cost just my two cents :undecided::twocents:
 

Jkust

Member
Dec 4, 2011
946
Black_tb said:
if the vehicle is payed for and your out only 5 grand and you have a 5 year warranty that isn't terrible considering what a whole new vehicle would cost just my two cents :undecided::twocents:

I suppose not when you consider opportunity cost and scarcity. The 5k could have been used in a million other ways instead of on a car whos cohorts tend to last 200,000 miles or more. Now, for example, instead of working until May to first pay your taxes to the government (presuming you are in the 49% that pay taxes not in the 51 that get a free ride), for some an extra 5k means the'll have to work until June to get to zero. An 06 with a bad engine is extraordinarily rare luckily. I really feel bad for the OP as you get no incremental benefit from a new engine than a properly working existing one. Properly maintained, the odds of a failure or needing the warranty, are slim at best.
 

xxxotiknightz

Original poster
Member
Dec 8, 2011
22
unfortunately the vehicle is not paid off and we owe too much to make trading in worth the money. Plus I love this thing. Its a great vehicle and the you can't beat the comfort for the price. its nearly 6 years old and has 93000 miles on it. if it lasts another 6-8 years I'll be more than happy. Plus maybe I'll get some of those lost horses back that escaped over time :undecided: The real luck in this situation is that I still made money on it. I re-enlisted in the military 3 weeks ago and got my sign on bonus at christmas. So I got 8k to use for what ever I want. I didnt want to use it on the engine but at least I'll still have some left afterwards to put in savings. Plus tax season is upon us and I should get some of the taxes they swiped from it back. All in all, yeah it sucks but somebody up stairs was watching out and took care of us. And I learned a valuable lesson: Keep up with your maintenance really closely.
 

Jkust

Member
Dec 4, 2011
946
xxxotiknightz said:
unfortunately the vehicle is not paid off and we owe too much to make trading in worth the money. Plus I love this thing. Its a great vehicle and the you can't beat the comfort for the price. its nearly 6 years old and has 93000 miles on it. if it lasts another 6-8 years I'll be more than happy. Plus maybe I'll get some of those lost horses back that escaped over time :undecided: The real luck in this situation is that I still made money on it. I re-enlisted in the military 3 weeks ago and got my sign on bonus at christmas. So I got 8k to use for what ever I want. I didnt want to use it on the engine but at least I'll still have some left afterwards to put in savings. Plus tax season is upon us and I should get some of the taxes they swiped from it back. All in all, yeah it sucks but somebody up stairs was watching out and took care of us. And I learned a valuable lesson: Keep up with your maintenance really closely.

Well at least you are upbeat about it. FWIW just my year end taxes caused me to write a $50,000+ check to the gov last tax season. That's just a small portion of what I paid during the year in federal taxes alone. Talk about swiping money. You earn it, they do nothing but steal it from you to give to the lazy sob's I see every day. When I hear people get money back, it just baffels me to no end.
 

dcrews

Member
Dec 4, 2011
4
xxxotiknightz said:
I re-enlisted in the military 3 weeks ago.


Noone has yet commented on this section of your post, so I will.

Thank you for your service to our country. Be safe out there.
 

TGFB87

Member
Dec 27, 2011
14
xxxotiknightz said:
Well, im taking the Denali home to Tennessee to my old mechanic. He's putting a new engine in w/ 5yr- 100k mile warranty. $5000 bought and installed.
Well, I just got my truck back and believe me, it runs better than ever. However, I wanted to share a few things that may be noteworthy...

- Depending on how much the engine is, and the labor cost, I think $5K is going to be a very conservative estimate, and I bet that they will lit you up for more labor. My cost was around $6K once I included the cost of seals, gaskets, water pump, belts, plugs, wires, exhaust manifold bolts, and pretty much any thing that is considered a wear item. The extra parts alone cost me around $800 on top of the cost of the engine. I know you may want to reuse parts, but this is a time where I personally think going the less expensive route is being penny-wise and pound foolish.

- Soak everything with PB Blaster... multiple times.

- This engine is a bear to get out because of clearance issues. In fact, I have been told that some Chevy dealers actually remove the body from the frame to make this easier. Saves a lot of labor - they claim they can do that part in about 45 mins.

- To make the new engine go in a lot easier, four bolts holding on the engine mount brackets were trimmed. They hung the engine up going out.

- Burping the air out of the cooling system is nothing short of a pain in the rump. Try to bleed air out when filling by removing one of the coolant crossover lines above the water pump. It took nearly 2 hrs to get all the air out of the system and nearly overheated the new engine a few times. Ill repeat: WHAT A PAIN!!

- Make sure you follow the break-in procedure for the new engine and then dump the oil after about 1000 miles. Keep track of all work done so that you have records for the warranty.

I hope this helps... let me know if you have any questions about my recent experience... I got to see most of it done and assisted in a bit of it.
 

jimmyjam

Member
Nov 18, 2011
1,634
TGFB87, just curious, are we talking about an I6 or a V8?

depending on the damage, say you spun a rod bearing and didn't run the engine too long like that, an engine is totally rebuildable. all you'll need to do replace the crank (you could mill it and use larger bearings but i wouldn't) and the rod that spun, all the bearings for good measure, testing the clearances and larger bearings if necessary. complete gasket set on rockauto is $500. I got a complete rebuild done for just north of $3k. i supplied the valvetrain parts because i had them swap the cam while in there. Thats including removal, complete motor tear down, and reinstall. thats me not lifiting a finger.

i later bought a forged stroker and did it all myself. well the only thing i needed help for was removing the hood. alldata puts the man hours for an removal/install at 17 hours and i think thats a little inflated for a professional with a lift, but at $75/hr thats $1250 labor. but its not as difficult as people say. i personally think people tend to over exagerate how hard what they did was so people will be more impressed with them. but removing a body for an engine R&R is crazy. sure, in my impala i could probably pull the engine with the radiator in there, and in the trailblazer that isn't happening.

as far as burping, if its a v8, pull the ECT sensor out of the head while adding coolant until it comes out of the sensor bung. you'll already have most of the air out. i've never had any issues.

trimming mount bolts? :eek: yikes
 

TGFB87

Member
Dec 27, 2011
14
It's a V8. The engine I got was $2750 from GM with a 3yr/100K warranty. For my situation, it really was the best choice over a rebuild.

I saw places say 17 -20 hours. And to be honest, my first hand account says that is extremely conservative. Sure, there are people that can do it in a lot faster time, Im surely not denying that. But after seeing the detail that went into this procedure, and the issues that came along with it, it would not be way off base to hit 25-30 hours.

A lot of the labor was related to all the prep work before the engine can be removed... and putting everything back together.

The thing is that the V8 is really crammed in there. There is not a lot of space to work around the sides of that thing. It was very apparent that GM never intended for these engines to come out. Heck, who thought it would be a good idea to run the drive shaft through the oil pan... I mean, really GM?

Some might call this a "Your mileage may vary" sort of thing. I would agree.
 

Jkust

Member
Dec 4, 2011
946
TGFB87 said:
It's a V8. The engine I got was $2750 from GM with a 3yr/100K warranty. For my situation, it really was the best choice over a rebuild.

There are a good number of LS2 TB SS full engines/ with tranny, shafts and everything else complete for suprisingly cheap on Ebay. Some have only 30,000 miles. I didn't search the 5.3 but am guessing the same deals can be had there as well. Am actually suprised how much a low mile complete set up cost.
 

xxxotiknightz

Original poster
Member
Dec 8, 2011
22
jcrews: thanks.

The mechanic i took it to is a good friend who has done a lot of work for me and my family. he's always been real fair with me on pricing. When he gave me the quote that included all new pumps, hoses, belts, etc. I talked to him and he's done a few trailblazers and said its a pain but not too bad. I did my own research before deciding on having him do it. GM wanted 3200 for their crate motor. The motor we ordered is from Jaspers rebuilt. He gave me a deal on the engine and the labor.
 

navigator

Member
Dec 3, 2011
504
I'm not a mechanic at all but for me to swap a 4.0 I6 for a Jeep Cherokee was over 40 hrs the first time and likely 30+ the second time and honestly outside of the top bolts on the back of the tranny they are pretty simple.
 

TGFB87

Member
Dec 27, 2011
14
Mine is in as well and I cannot believe the difference. I also changed out the trans, transfer case, and diff fluid at the same time. It really does run like a new truck. And while it was a lot of cash, its a whole lot cheaper than buying something new and going into debt.

Dont forget to change the oil at 1000 miles and keep track of maintenance for warranty purposes. (Trust me - I hear the smallest knock in this engine, its getting warrantied!)
 

Jkust

Member
Dec 4, 2011
946
xxxotiknightz said:
new engine is in and it runs like a champ. I hated to spend the money but it was worth it.

TGFB87 said:
Mine is in as well and I cannot believe the difference. I also changed out the trans, transfer case, and diff fluid at the same time. It really does run like a new truck. And while it was a lot of cash, its a whole lot cheaper than buying something new and going into debt.

Dont forget to change the oil at 1000 miles and keep track of maintenance for warranty purposes. (Trust me - I hear the smallest knock in this engine, its getting warrantied!)

Guys post some pics. When you say you can't believe the difference, how do you mean?
 

xxxotiknightz

Original poster
Member
Dec 8, 2011
22
I was going to post a pic but everything I have is too large. Just imagine a 2006 Envoy Denali swb in metallic pewter grey. :biggrin: It feels more powerful to me. All those escaped ponies are back and pullin strong.
 

Jkust

Member
Dec 4, 2011
946
xxxotiknightz said:
I was going to post a pic but everything I have is too large. Just imagine a 2006 Envoy Denali swb in metallic pewter grey. :biggrin: It feels more powerful to me. All those escaped ponies are back and pullin strong.

Yes of course they are too large. You have to use a hosting site like photobucket or one of the other hundreds of sites. It is a good time to learn so we can see the new engine.
 

TGFB87

Member
Dec 27, 2011
14
I only have a few pics and I will try to get them up here in a bit.

The differences I am noticing is first, how quiet the new engine is, especially during warm up. No more ticking, no more piston slap in the morning, and it generally seems quieter on the road. Considering that this is our "road trip" vehicle, thats a nice plus.

Acceleration is very smooth and effortless, even more so than before. It just seems like it has its youth back.

Fuel economy is about the same, which Ill take either way. Hopefully it will even get better as it breaks in.
 

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