Mobil 1 5w-30 2002 Chevy Trailblazer 5349 miles

[MN Driver]

This is the second UOA for this 2002 Chevy Trailblazer. This is the second interval with synthetic oil. 75% driving in this interval is highway use but the drive to work is only about 10 minutes or so. There was no noticeable oil consumption in this interval. The oil Filter was not changed in this interval.


Summary
Engine: GM 4.2L Inline 6-cyl
Filter: Purolator PremiumPlus L25288
Oil : Mobil 1 5w-30 SuperSyn SM grade

Total Miles: 61,637 miles
Oil Interval: 5,349 miles
Duration: ~1 year 10/14/05-10/28/06
Make-up Oil: 0 quarts
GM Oil Life Monitor: 25% life remaining - 1,783 more miles... It was at 13% last interval after 7,806 miles.
Blackstone Labs


Aluminum 4
Chromium 0
Iron 40 FLAGGED This was 23 last time - Universal average 26
Copper 7
Lead 0
Tin 1
Molybdenum 88
Nickel 1
Manganese 1
Silver 0
Titanium 0
Potassium 1
Boron 58
Silicon 10
Sodium 4
Calcium 2271
Magnesium 13
Phosphorus 681
Zinc 752
Barium 0

TBN: 2.2 Same as last time
Viscosity 58.3 SUS @210F
Flashpoint 330F FLAGGED - Should be above 365
Fuel 1.8 Should be below 2 - This was zero last time
Antifreeze 0.0
Water 0.0
Insolubles 0.3% Same as last time



Oil was drained when the sample was taken and then filled Mobil 1 5w-30 SM grade again. Things were going well last time but it seems that even though it takes a highway trip to and from work that it needs a bit longer drive on the weekends to burn off any fuel that builds up. It's taken a toll on Iron, it doesn't look devastating high but is nearly double the iron from the last interval which was 2457 miles more than this interval. My goal was to change the oil every year on this vehicle before winter as it generally won't be getting more than 7-8 thousand miles per year anyway but this UOA shows that I might need to change something. Would driving for 30-45 mins on during the weekend take care of the fuel that is causing both the flashpoint and Iron wear?

Comments?

 

[Triple_Se7en]

Have you done alot of long idles or long warmups with it last winter?

What synthetic oil was in it when the iron was 23?

So you are saying that this Purolator filter was used in the prior oil change - meaning it has over 10K of service?

 

[MN Driver]

It was Mobil 1 of the same viscosity last time, only difference was that it was SL grade last time and SM grade this time. This engine is never idled as there is no need to and is only warmed up for one minute with no need to idle to melt ice as it is always parked in a garage. The filter was new for this OCI, it has the same interval as the oil. I misworded that, I meant that it wasn't changed 'during' the interval, sorry about that.

I'm thinking it is the 10 minute highway trip to work not being long enough, this vehicle is not driven hard as once its on the highway it stays the same speed and the onramps that this vehicle gets up to speed with are quite long and traffic isn't heavy often.

I'm just not quite sure what measures to take to get that Iron to drop.

 

[toneloc12345]

try a different oil, maybe GC if you want to keep syn.

 

[MN Driver]

I don't see how oil type has anything to do with the high Iron caused by fuel, could you explain why you think that switching to GC would change that? I could see looking at a difference if fuel dilution wasn't a problem but I am looking at removing this fuel dilution problem. Any advice on that? Would throwing a long trip in every weekend be enough?

 

[Cutehumor]

Iron and fuel. I bet if you switch to another brand instead of mobil 1, iron will drop by half. Don't you Minnesota guys always have fuel dilution issues in winter? T-keith was in the same boat with his buick

 

[MN Driver]

This is the only vehicle with this issue as I drive two 30 mile highway trips that take 45 minutes to complete with my own car. It would have to be trip time vs. temperature and whether or not things get hot enough to burn off any dilution before wear increases. This one however is not mine... I suppose that it could be an issue reduced by changing brands of oils, too bad it already has Mobil 1 in it as that is what the owner purchased and it will be there until next year probably. I am just going to communicate with him that we need to run long highway runs on the weekend to burn off fuel before we have any issues.