Only the V6 has timing chain issues. The V8 is basically bulletproof. Reliability varies based on previous owner maintenance. but I've not seen any common issues that actually affect drivability of the car.
If you get the 07 you'll get the 6spd trans and you shouldn't have any issues with poorly manufactured cats.

Heated steering wheel is common failure and to my knowledge there are no remaining stock of that style wheel anywhere.

 

Only the V6 has timing chain issues. The V8 is basically bulletproof. Reliability varies based on previous owner maintenance. but I've not seen any common issues that actually affect drivability of the car.
If you get the 07 you'll get the 6spd trans and you shouldn't have any issues with poorly manufactured cats.

Heated steering wheel is common failure and to my knowledge there are no remaining stock of that style wheel anywhere.

I thought the 6 speed didn't come until the second gen in 2008?

 

Thanks for the info! Would you recommend staying away from the V6 and holding out for a V8? I need a car that is reliable. My last car was horrendous when it came to reliability.

 

I wouldn't go anywhere near the V6.

 

No timing chain issues but some Northstar's leak like a sieve

 

Hello...

I have just replaced the timing chain tensioners on my 2006 STS V-8. The plastic guides were worn and were intermittently very noisy. The tensioner parts are amber in color in the photo below (photo was sourced from somewhere in these forums...thanks for posting!)
The actual tensioner parts are relatively inexpensive...labor is where the money's at on this job.

Oh, and have CEL 0420/0430 I'll deal with this in June.

 

Thanks for the info guys. I used to have a 2001 Eldorado ETC and that Northstar went through oil like crazy! As long as you kept putting oil in it, that thing ran like a champ and I had no issues with it.

 

Ultimately this will not be a problem free LS car like you're accustomed too. If you go with the northstar you'll have the various oil leaks, a bit less than fwd models but still. Cam cover seals, valve covers, intake bolts loosening up etc. Steering wheel heater. Codes for air intrusion behind the maf etc. Heater cores (a royal pita) are common. Door handle micro switches and antennas. Overall I'd say go for it but be prepared to turn a wrench periodically or spend some money for repairs. I was a glutton for punishment with my '05 that I bought a '08 V. Yet inevitably I'll buy another one because I love the northstar, rwd, and sts size that hasn't been offered since.

 

and sts size that hasn't been offered since.

The gen 3 CTS is about the same size as the STS. I went from an 08 STS to a 2014 CTS. I loved my STS but the CTS is a better car.

 

Seems a little smaller but overall I'd agree with that. Especially the being a better car part.

 

My tensioner arms went. Had to replace them and the tensioners.

 

My tensioner arms went. Had to replace them and the tensioners. View attachment 450521

Which engine is this?
How did you know of the failure?

 

I just recently bought an 05 STS with V6, wasn't running, was told it needed a motor. After detailed questioning I was 99% sure it was the timing chains. I am a mechanic and thought "what the hell" and got it for $900. Opened her up and yep, the lower tensioner was toast and primary chain slipped 3 teeth. Got a chain set and water pump from Ebay ($155), had to replace the oil pump due to it being one of the non-mellings bastards ($180), 04/05 only (lower chain guide wont bolt up). The following weekend, she lives.
I had the same problems everyone has with these, door switches, did the switch swap mod. P0420/430 codes, did the spark plug fouler mod (Dorman 42009). Bose speaker issues, swapped the amp, good as new (see my recent post).
The motor to avoid is 04-07 3.6L VVT, it has a silent primary chain but double roller (Bicycle chain) secondaries. In 08 they went with all silent but was only marginally better. I believe its the oil change interval that is the real cause for the failures. I change mine at 5K no matter what and still have 40% life still on it.

 

It's a Northstar. It started making a lot of clanking noises. I forgot which codes it posted but think it was the cam sensor position. I recall someone posting that they changed their oil and the problem went away. When I drained the oil, it looked shiny. Someone came by and looked at he oil and told me it was full of metal.