2005 Trailblazer getting a new engine

[The_Eric]

In keeping with my photo-logging for your entertainment, I thought I'd make another thread on another engine swap job. (other is a beat to &^$* '93 F250). Vehicle is a very clean and well maintained, one owner rig with 109k miles. It developed a knock that went away as it warmed up a bit. Owner called me up and started quizzing me on my opinion. He had worked a few mech jobs before and does somewhat know his stuff. Thought it could be a scored piston. Called back later to say it's getting noticeably worse- I told him that pretty much ruled out piston slap as it pretty much gradually gets worse.

I went and picked it up, then let it sit outside to get cold again. Once cold, I plugged my scan tool in, started it up and proceeded to shut injectors off to isolate which cylinder it was (you could hear it was a piston noise). When I got to #3, it quieted down noticeably. Pulled #3 coil and plug and stuck the bore scope in there to find that the bore was scored at the thrust axis. If the bore is scored, I can imagine what the piston looks like.

So the owner thought it over and decided to go with a re-man. Once I get time and room, I'll bring it in and start snapping some photos of the swap. If I think about it, I'll even get a quick video of the engine knocking... Sorry guys, no pics yet- just wanted to get a thread going now while I've got some time so it wouldn't take quite so long when I get pics.

 

[andyd]

is this an Atlas I 6?

 

[The_Eric]

Yup

 

[MolaKule]

Cool. Will be looking forward to see your progress on the rebuild.

 

[Warstud]

Why did you have mention a motor failure on a vehicle that I own. Why?

 

[George7941]

Most recent engines are super reliable if not abused. I would be really disappointed if a vehicle I have with only 109K miles required extensive engine work.

Of course that engine (chinese made?) does not have a good reputation. I try and avoid buying a vehicle with a poor engine. I love I6 engines but will not buy that engine because of its reputation. When I was looking around for a truck in 2006, the phrase that came up with the GM 4.3 V6 was "as reliable as a stone axe".

 

[JTK]

I used to follow all that was GMT360 quite a bit when I owned a 2005 w/ the Atlas/Vortec I6 for a few years. I don't recall ever hearing about one scored cylinder. What would cause that? Lean detonation?

 

[MolaKule]

Originally Posted By: George7941
Most recent engines are super reliable if not abused. I would be really disappointed if a vehicle I have with only 109K miles required extensive engine work.

...When I was looking around for a truck in 2006, the phrase that came up with the GM 4.3 V6 was "as reliable as a stone axe".


And they are. I have a 1999 S-10 with the 4.3L engine and it runs like a banshee.

My SIL still has a TrailBlazer with the I6 and it is running strong at 185,000 miles.

 

[andyd]

An American DOHC I-6, aluminum head and block with liners ? Please post progress

 

[Bottom_Feeder]

Originally Posted By: George7941
Of course that engine (chinese made?) does not have a good reputation.

Chinese made? Why would you think that?

 

[George7941]

Originally Posted By: Bottom_Feeder

Chinese made? Why would you think that?


Dunno. I somehow thought that I heard those engines were made in China.

I stand corrected.

 

[The_Eric]

According to wiki, they were made in the U.S. until the plant closed.

 

[JTK]

Yeah, the other one that always got thrown around was the Trailblazer and inline-6 were an "Isuzu product". Mainly because of the Isuzu Ascender, which was a re-badged Trailblazer.

It's too bad this 4,5 and 6cyl engine never became more than what they were.

 

[01rangerxl]

Originally Posted By: George7941
Originally Posted By: Bottom_Feeder

Chinese made? Why would you think that?


Dunno. I somehow thought that I heard those engines were made in China.

I stand corrected.


That was the GM 60* V6 that was made in China.

Usually the 4.2L I6 Atlas is pretty good, but I've seen them go before 150K mi too. I quoted an engine on one not too long ago with around that many miles. [censored] happens.

 

[daves87rs]

I've heard a few go early, but most I know are still going..some as high as 240k..

 

[Falcon_LS]

Originally Posted By: George7941
Most recent engines are super reliable if not abused. I would be really disappointed if a vehicle I have with only 109K miles required extensive engine work.

Of course that engine (chinese made?) does not have a good reputation. I try and avoid buying a vehicle with a poor engine. I love I6 engines but will not buy that engine because of its reputation. When I was looking around for a truck in 2006, the phrase that came up with the GM 4.3 V6 was "as reliable as a stone axe".


The LL8 was produced in Flint, MI and was on Ward's Best 10 Engines list from 2002 - 2005. It got upgrades in 2006 and that was that until production of the GMT360 ended in 2009. These engines are well sought after used, since people turbo them.

We got a '07 TrailBlazer in the family with 248,000 miles on it - all original. It gets beat on quite a bit, and granted it's only had Mobil 1 0W-40 it's whole life (even under warranty), it still runs like it did new. My '05 Envoy has a little over 105,000 miles on it, sees WOT daily, and I have no complaints.

 

[jkasch]

110,000 on my '05. 3,000 mile conventional oci (sue me

). Runs like new and no perceptible oil usage.

 

[The_Eric]

Originally Posted By: jkasch
110,000 on my '05. 3,000 mile conventional oci (sue me

). Runs like new and no perceptible oil usage.



This one has had it's oil changed at 2000 to 3000 mile intervals. Oddly enough, the owner was the one who wanted 2k changes, and the shop that usually does his oil changes (only does oil changes, brakes, exhaust and alignment) advised the 3k intervals.

 

[Falcon_LS]

I guess it boils down to whatever makes you sleep better at night. I follow the OLM, and once it's down to 50%, I do a simple drain and refill (~6 quarts) . At the 1% mark, it's oil (7 quarts), oil filter and air filter.

 

[George7941]

Wow, your air filter regimen is totally different from mine. I changed the air filter in my truck for the first time after nine years of service/ 90K miles. I monitor it with a restriction gauge.