The oil sensor in our 2008 Pontiac G8 GT finally told us it was time for an oil change. We checked records and the last time we got new oil was 13,000 miles ago! We wanted to send an oil sample off to Blackstone Laboratories to see what they could tell us about the condition of the oil. We wanted to know if the oil was truly done, as the sensor indicated, or whether there was any life left in the slippery stuff.
Our first stop was to look in the owner's manual to see what Pontiac had to say about oil changes.
"When the system has calculated that oil life has been diminished, it will indicate that an oil change is necessary. ... It is possible that, if you are driving under the best conditions, the oil life system might not indicate that an oil change is necessary for over a year. However, the engine oil and filter must be changed at least once a year."
Still, we were curious about the condition of the oil and why the sensor finally went off. We tried to use the "vampire gun" that Blackstone gave us to suck out a sample by inserting a long tube down the dipstick opening into the oil pan. However, we came up dry. We took the G8 to Boulevard Buick Pontaic GMC, in Signal Hill, CA, where the service advisor said the baffle over the oil pan prevented anything but the dipstick from being inserted. We asked him to keep a sample for us while doing the oil change.
By the way, the oil change, inspections and tire rotation was only $39.95. It took them two hours to do the service and clear two recalls. We'll report back on the condition of the oil after we hear from Blackstone labs.
beach15 says:
12:56 PM, 12/26/09
I get to 5000 in my GT and get antzy, even though the Mobil 1 is just a few shades darker;-) With a nearly 9qt. oil pan, the sheer volume does a lot towards increasing the interval--there's just a LOT of oil stored in there, like a big rig.
Can't wait to see the Blackstone results after a 13k run in the L76. Should be a good read.
rayainsw says:
02:55 PM, 12/26/09
"...and clear two recalls."
And no attempt to remedy the transmission issues
IL has complained about for so long???
[ sigh ]
txmatt1 says:
09:58 AM, 12/27/09
I'm not familiar with the G8 specifically, but I think in most cases the term oil sensor is a misnomer. Most of these systems don't have any sensor that directly measures anything about oil condition other than temperature. Instead they us some algorithnm based on inputs from other sensors (odometer, RPM, oil/coolant temp, etc) and the specifications for SM-rated oil to estimated how the oil should be aging given the driving conditions experienced.
pezzy669 says:
08:10 PM, 12/27/09
Blackstone is definitely a decent lab, please post the results once you receive them.
I use Blackstone about every 30,000 miles (every 3rd oil change) on my '06 Jetta just to make sure no issues are arising (coolant leaks, wear, etc). Great preventative care for a car (just like checking your fuel economy at each fillup, checking oil, etc.).
cr_driver says:
04:19 PM, 12/28/09
Definitely waiting on that lab test.
cr_driver says:
04:19 PM, 12/28/09
Definitely waiting on that lab test.
syt_shadow says:
06:07 AM, 12/29/09
I definitely look forward to those results. I think it's very interesting to know what wear your engine has, whether your oil has any life in it, etc etc.
You should send an oil sample to Blackstone every time you finish a Long Term test.
stingray454 says:
12:03 PM, 01/ 4/10
I bet the lab results will show the oil is fine. I had the oil analyzed by Blackstone about a year ago when I relied on the oil life monitor for changing the oil in my Z06, which worked out to about 8,500 miles. The lab results showed everything was normal with the oil, and it still had life left in it, estimated to be good for another 1,500 miles.
It was good to know, as I didn't trust these oil life monitor systems before. Now I do.