Sounds about right, if u go by the manual it states min once a year or 11,000 miles. Alot of people are still hesitant about going by the computer but people have also had their oil tested after and had no issues with it. Do a search, it has been discussed many times

 

I change mine every 5-7k rather to be safe than sorry

$7k for an engine

 

How does that oil sensor thing work anyways.

The oil life monitor uses multiple pieces of data, like RPM's and length of drive to calculate oil life. I believe mine comes on every 2 oil changes. I change my oil about 3500 miles running Mobil 1. It did go 3 changes before lighting up once.


Running the Syn blend you are I'd say you're good using your interval.

 

Sometimes the GM engineers baby the vehicle with things like Torque Management in the PCM, robbing us of performance but saving them warranty $$.

I give the engineers the benefit of the doubt on the Oil Life Monitor system, because it's such an obvious one for engineering management to review closely before letting it out in public. They're not stupid. Upper management is not as talented in their jobs as the engineers, is my opinion.

 

Sometimes the GM engineers baby the vehicle with things like Torque Management in the PCM, robbing us of performance but saving them warranty $$.

I give the engineers the benefit of the doubt on the Oil Life Monitor system, because it's such an obvious one for engineering management to review closely before letting it out in public. They're not stupid. Upper management is not as talented in their jobs as the engineers, is my opinion.

This comes from an engineer I'm assuming? LOL :crackup:

 

AMSOIL recomends 40000 km (24000 miles) or 1 year wichever comes first.

 

I'll relay my experience with my 2005 Grand Prix running 4.5 quarts Mobil 1 full synthetic and a AC Delco oil filter (although I prefer Wix, I figure the test was best done with the manufacturers product).

OLM indicated an oil change required at about 13,500 miles - about 6 months service for me. I sampled the oil as instructed mid-purge and sent to Blackstone Labs for their analysis. The report indicated that the oil additive package would still be suitable for additional miles of service, however the particulate contamination of the oil was high - indicating the limiting factor as the filtering system, not the oil itself. Based on these results, I change my oil at 5,000 mile intervals to ensure proper filtering and reverted back to a non-synthetic oil as the shorter change intervals do not support the additional cost of full synthetic oil.

Although I've not specifically tested my Trailblazer, the technology in both vehicles is similar and I don't trust the OLM.

 

How many miles were on the vehicle??

If they say the filtration is bad, then you might try switching filter brands?? Every UOA sample I've sent in with a Pure 1 oil filter, they've said "Filtration is excellent! Whatever oil filter you're using, keep using it"

OLM has proven to be gnat's rear end accurate for everybody I know (several on this forum, and on BITOG) who have turned in samples changed by it... Because of break-in metals, I changed oil at 200 miles, 2000 miles, 5000 miles, 10k miles, and 15k miles, then I started using the OLM, which usually says between 10k and 11k with our duty cycle...

Mike

 

Just hook up a trailer and watch the % drop quickly.