Mobil 1 5w-30; 5k mi; GM 5.3L 200k mi

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This is a 2005 Silverado with 200,000 miles and 5400 on this oil change.
This is the first oil sample on this engine.
Wix oil analysis - ( first time and I really like)
Mobil 1 5w-30 with Fram Ultra XG3675

Iron 35
Chromium 1
Lead 10
Copper 7
Tin 2
Aluminum 4
Nickel 1
Silver less than 1
Titanium less than 1
Vanadium less than 1

Silicon 16
Sodium 225
Potassium 235

Magnesium 635
Calcium 1350
Barium less than 1
Phosphorus 742
Zinc 894
Molybdenum 74
Boron 17

Water less than 0.05
Coolant no

vis @ 100 10.8

Base # 3.9

The comments states possible antifreeze contamination.
I have not noticed the level going down.
Any thoughts.
 
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Congratulations on 200,000 miles. Less than 2% of the general public achieve that.
smile.gif
 
Originally Posted by sweezy722


The comments states possible antifreeze contamination.
I have not noticed the level going down.
Any thoughts.




What kind of antifreeze is it running, and do you change the antifreeze on a regular basis (whatever the service interval is for that kind)?
 
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I change the antifreeze every 4 years which happened to be last year.
I use Supertech antifreeze mixed about 60% antifreeze to 40% distilled water.
 
Check the head no. on the pass side. GM had some bad castings that crack in that year. 706 is a bad no. There is a TSB on it. search Castech heads.
 
Ok. Both heads say 706.
I was hoping for something smaller and simpler.

I just changed spark plugs 300 miles back and they all looked normal.
If it is the head would 1 of the spark plugs show?

Thanks.
 
Originally Posted by Snagglefoot
Congratulations on 200,000 miles. Less than 2% of the general public achieve that.
smile.gif




That's nothing on a LS Vortec engine lol, My 05 Silverado was a beat to [censored] farm truck in rural Oklahoma and still kicking at 286K !!!


Also have a '01 Suburban with same engine and 265K miles still going strong, But it has been pampered with full syn and mostly hwy miles lol

Dave
 
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Absolutely coolant here, elevated potassium and sodium with bearing involvement with the elevated lead. Time to start looking for the source, this UOA gave you a heads up something is amiss, exactly what they're meant to do.
 
Yeah, the elevated Sodium and Potassium jumped right off the screen when I looked at the UOA. There are some issues to deal with.
 
Originally Posted by spasm3
I have never done a uoa on my avalanche. Guess i will now. Its in the affected year range for the bad heads.


Any 706 Castech casting can be affected, Used on a TON of 4.8L/5.3L engines starting in 2001 & ending in 2006. The actual failure rate is pretty low, So a UOA is needed!

Castech castings can be identified by the "Battery" looking casting mark under the Valve Cover.....The picture is of my 5364 L92 that were cast by Castech but not effected with this issue, The Black circle is what the mark looks like.....The Yellow circles are where it's normally located on 706 heads.

There is a secondary identifier that I've had 100% luck with on identifying Castech castings......There will be a Triangle casting line below each spark plug highlighted in the second picture.

[Linked Image]

[Linked Image]
 
I just looked, i could not see the drivers side , but the passenger side is 706
mad.gif
I assume then the drivers side is as well.

Have the triangles too!
 
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Don't freak out just yet.....Keep in mind there are Millions of these heads in service! Get a UOA & move on from there.

The TSB was created for vehicles losing coolant with NO external leak to be found.....Are you losing coolant?
 
I just checked my 2005 Avalanche and the casting number 706 is easily seen on the passenger side head. I've never had to add coolant so I'll just drive it and hope for the best. Does anyone know how widespread this cracked head issue is?
 
Originally Posted by clinebarger
Don't freak out just yet.....Keep in mind there are Millions of these heads in service! Get a UOA & move on from there.

The TSB was created for vehicles losing coolant with NO external leak to be found.....Are you losing coolant?



Thanks, not freaking out. But concerned. I recently replaced all the cooling system hoses and the water pump and clutch fan. Was loosing some coolant from the pump gaskets. Filled it back up check it last week as its getting to towing season , and its a bit low in the reservoir . I thought that was just due to air in the system purging. But now i'm not so sure. I will get a uoa. Just changed the oil so i'll get one later this season.
 
Originally Posted by FlyNavyP3
Absolutely coolant here, elevated potassium and sodium with bearing involvement with the elevated lead. Time to start looking for the source, this UOA gave you a heads up something is amiss, exactly what they're meant to do.



Big +1 ^^^^^^^^^

Best function of a UOA.
 
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