QHP | 4,598 MI | 07 GMC Acadia w/bad timing chain

[MedicRxDoc]

Here is the UOA on my 2007 Acadia within 50 miles of the check engine light coming on. The high fuel is probably because I had to idle the car for Onstar to do diagnostics on the CEL and because I also needed coil pack replaced.

Code:


MI Oil 4,598 UNIT 5,653 4,937 5,483 2,938 UNIV

Unit 43,667 AVGS 39,069 27,666 19,221 13,738 AVGS

Date 03/11 11/10 12/09 04/09 06/08



ALUM 4 4 4 3 6 3 5

CHROM 1 1 1 1 1 0 1

IRON 74 58 43 47 116 12 28

COPPER 4 5 4 5 6 5 15

LEAD 1 1 2 2 1 0 2

TIN 3 2 2 0 2 1 1

MOLY 43 54 46 42 23 118 67

NICKEL 0 1 1 1 1 0 1

MANGAN 3 3 4 2 3 1 3

SILVER 0 0 0 0 0 0 0

POTASS 0 1 0 2 1 0 2

BORON 50 29 49 10 6 28 41

SILICON 24 23 37 24 14 15 15

SODIUM 8 25 1 90 5 4 48

CALCIUM 1704 1799 1920 1983 1976 1412 2178

MAGNES 8 9 9 9 12 6 51

PHOS 592 597 602 627 615 550 670

ZIN5C 761 766 808 771 824 667 828



SUS Viscosity @ 210°F

55.5 56-63 58.7 55.9 55.3 53.4

cST Viscosity @ 100C

8.93 9.1-11. 9.84 9.04 8.86 8.30

Flashpoint in °F

340 >365 385 385 385 350

Fuel % 1.3
Antif% 0.0 0.0 0.0 ? 0.0 0.0

Water % 0.0
Insols% 0.5
TBN 2.2 2.0 2.3


Here are Blackstone's comments on this UOA:
CHRIS: We found an increase in iron in this sample taken at 43,667 total miles. It could be from the timing chain or camshaft issues you're experiencing. Fortunately, the other wear metals look good. This level isn't quite as high as we saw a couple of years ago, but it's still cautionary. The low viscosity is likely due to the
1.3% fuel dilution. The fuel is likely from idling before the sample was taken and it's not a problem. Air and oil filtration were fine. Let us know what you find out at the dealership. Hopefully it's a simple fix.

 

[The Critic]

GM's 5/100 warranty covered the timing chain, I hope.

 

[21Rouge]

Originally Posted By: MedicRxDoc
Here is the UOA on my 2007 Acadia within 50 miles of the check engine light coming on.

Here are Blackstone's comments on this UOA:
CHRIS: We found an increase in iron in this sample taken at 43,667 total miles.

This level isn't quite as high as we saw a couple of years ago, but it's still cautionary.


Thanks for the post Medic but as noted by BStone your engine showed significantly higher iron 2 years earlier so I am not convinced that the spike you saw most recently is indicative of the timing chain CEL

.

 

[ZZman]

I thought the Calcium should be in the low 2,000's?

 

[REDDOG]

Medic,

Have you been following the oil life monitor to establish your ocis?

 

[21Rouge]

Originally Posted By: ZZman
I thought the Calcium should be in the low 2,000's?


From the VOA I had done for this oil a few years back the calcium level was over 2500:

http://www.bobistheoilguy.com/forums/ubb...rue#Post1547173

 

[addyguy]

Ouch......

 

[MedicRxDoc]

Originally Posted By: REDDOG
Have you been following the oil life monitor to establish your ocis?


No. My OLM would take me to about 10K miles which I believed was way to long for this engine.

And yes, the repair was covered under my warranty.

 

[MedicRxDoc]

Originally Posted By: ZZman
I thought the Calcium should be in the low 2,000's?

Thanks for pointing out that descrepancy. I went back and checked my records. The fill was 2.5 quarts of QHP with 3 quarts of QTorquepower. This should explain the low calcium. I will modify my record book (I keep the filter box top with notations in my garage).

Sorry for the confusion.

Here is the oil change history for my 07 non-DI GMC Acadia

Code:


DATE MILEAGE OIL BRAND FILTER OLM%

11/23/07 5,300 Took delivery of the vehicle. Dealership owner's car.

12/26/07 6,441 Gastrol GTX 0 Fram

06/18/08 10,800 Pennzoil Yellow SuperTech

10/##/08 13,738 PYB ST Filter?

04/02/09 19,221 SuperTech Syn Napa Gold 25%

07/26/09 22,660 QHorsePower Napa Gold 60%

12/02/09 27,660 QTorquePower Napa Gold

05/29/10 33,416 QTorquePower Napa Gold

11/08/10 39,072 QHP/QTP Mix PF-48

03/23/11 43,682 Timing chains replaced. Oil dealer bulk & ACD PF-48. Ignition coil#5 replaced.