Well, all I can say is my head gernaded at 70K miles...

 

GM stopped production of all atlas engines, not just the I5.

Mainly because they stopped making the vehicle's they used them in, the gmt360 (trailblazer and its GMC and Buick versions), the gmt355(2004-2012 colorado/canyon/I-series)and the gmt345(hummer h3) are no longer in production... and yes more efficient, higher hp producing engines have come along.

 

The inline 5 was a version of the inline 6 used in the trailblazer with 1 less cylinder. The engine had some known issues like premature valve seat wear due to inferior material used in the 3.5L. The 5 cylinder was used due to package restraints(engine bay size). It was replaced in the second Gen Colorado by a 3.6L v6 which is a multiplatform engine used in everything from passenger cars to pick up trucks, which suffered from its own development issues. The inline 5 is a very unique engine with very few manufacturers using it. It can be harder to balance the engine to get it to Rev smoothly necessitating the use of balancing shaft(s) on the bottom end. I personally love the uniqueness of an inline 5 and the confused looks I get when I say it has a 5 cylinder, and the unique exhaust sound.
To sum it up GM stopped using it because they had a corporate engine in the 3.6 that they had already certified in multiple platforms that used direct injection for better fuel mileage, reducing tooling investment cost by using an existing engine. GM still made mistakes with the v6 though, carbon deposit build on the valves due to combustion chamber injection and oil filter packaging issues that if filter is not properly replaced can lead to oil galleys getting plugged.

 

I have 255,000 happy miles with NO engine problems on my 2005 I-5.
One thermostat replace, changed hoses and radiator out of prevention, only got 200,000 miles out of them.
Uses 1 pint of oil during the 8,000 - 10,000 mile oil change intervals, I change when the DIC shows "Oil Life".
No durability issues here.
My "Fuelio" app has shown 20 mpg avg. for the last 150,000 or so miles. I change my fuel filter every 35,000 miles and my air filter every 50,000 miles. No fuel pump change yet. Spark plugs replaced at 122,000 and 200,000 and plan to change at 300,000 miles.
Mobil 1 Extended Life Syn 5w30 ever since brand new.
The I-5 is all right in my book.

 

Sounds awesome...I hope my 2005 I5 gets that many miles!

 

For sure the 3.6 V6 is better in many ways. It's packages better, more HP, more torque. Better mileage.

But you can't match the character of the I5. I think there is currently 1 I5 on the market today (Audi TT-RS). Both the TT and the Colorado sound exotic.

 

I'll take a truck without a high pressure fuel injection pump that I can work on any day of the week.

 

Yup! My '04 Has 188k, and still runs great. It's got some quirks, but is otherwise a great truck. I'm not worried about it having any issues, since I have a different vehicle for my offroad adventures now.

 

Yep, my I-5 has been a good one, and it is good to hear others getting great service out of theirs, too. I am looking forward to sailing past 300K in another year or so.???

 

really couldn't tell you but my 2012 got 19 mpg in town and nearly 26 on the highway, it did, after 120k miles start using a lot of oil. it didn't smoke and it didn't leak it but half way to the next oil change it wasn't unusual to use three quarts of oil.

 

how can you find out if gm has I-5? sorry im new and just curious?

 

As my '05 I-5 approaches 300,000 miles I am prepared with new Mobil 1 5w30 High Mile syn oil, AC filter, AC Delco Iridium plugs, upper/lower rad hoses, thermostat, Peak GM Dexcool AF, fuel filter, Air Filter and 4 new General tires just installed ($100.00 Rebate via visa gift card going on right now!). I replaced the factory shocks around 230,000 - should have done that sooner. 3 of them were pretty much shot, the 4th was blown and just along for the ride. Monroes for the win! It's been a good truck, I bought it brand new Christmas Eve '04. Each battery has averaged 7 years each.

 

Alice (my 05 I5) is still running well at 428,000. She's had 3 trans rebuilds, countless wheel bearings and the 2nd water pump went out over last weekend, diff, alt, fuel pump, heater motor. The soy based wiring harness has had a few issues but this is the toughest most reliable truck I've owned for the last 20 years. Mobile 1 since new.

 

I love my 05 Ls Sport zq8. It's the perfect vehicle - handles like a sports car and gets 19mpg every time. But it has almost 190k and I'm worried about the cam chain. It makes a lot of noise when cold and the cam sensors keep going bad. I started a thread here a few weeks ago about the cam position sensors going bad 3 times in the last 4 years. Plus it uses two quarts of oil in the 4k miles between changes. I found an 06 long block at a junkyard that needs a rebuild, so I'm thinking of building that up for a quick swap. But then maybe it could still go another 100k. You guys that have had the failures, what where the symptoms and how long did it take from first signs to wipe out?

 

Something I read once is the best 2 things we can do to help against cam chain issues (Among others) is to change oil sooner than the oil life tells you (Perhaps around 5K or so) and to use Dexos rated 5w30 syn oil (I have always used Mobil 1 Syn 5w30 with an AC PF61 Oil Filter). The Dexos rating is important. (Look it up) I really don't think going much longer on oil change intervals helps you any in the long run.
I am a huge fan of Mobil 1 Synthetic Oil, I use their 15 w 40 Turbo Diesel Syn Oil in my mowers and home generator, never an issue. I used to change that once a year, now I change it twice a year. The turbo diesel formula is designed for high heat and heavy duty. Excellent protection.

 

My 05 colorado i5 has 349k miles, no issues until the other day... just got my parts and I'm ready for the nightmare design prepping for open heart surgery (new timing chain) doing it myself.. hoping for the best...

 

How did it go? A lot of my noise when cold was the water pump. Apparently the bearings have been bad for a year, but it never leaked. Changed the pump and PS pump, now it's quiet as new. Sill uses a quart of oil every 1k, but maybe it will last a while longer.