Pontiac GTP L67 3800 PP 5w30 5.4k

[ATS-V]

A little background, this engine has for years had slight coolant seepage (lower gaskets). In mid 2010 the vehicle usage had changed from a daily driver to a short tripper. In early 2013 the upper manifold gasket developed a vacuum leak so at this time I did lower intake gaskets and buttoned it all up. Care was taken to not let any coolant into valve galley and a quart of oil was poured down galley as a precaution. Oil was changed with the cheapest I could find (Peak 5w30 IIRC) and ran for 500 miles. This analysis is the second change after the Peak oil. From my research the Peak uses sodium as an additive although I can't seem find how much. I also haven't added a drop of coolant since the repair. I'm a little surprised that Sodium and iron numbers. Questions/comments welcomed.

Code:

OIL TYPE        PP       PP       PP       PP       PP       PP       GC       GC       GC       GC       M1       M1       M1       M1-EP    M1       M1       M1       M1              
OIL GRADE       5w30     5w30     5w30     10w30    5w30     5w30     0W30     0W30     0w30     0w30     5w30*    5w30*    5w30     5w30     5w30     10w30    5w30     10w30           
MILES IN USE    5.4k     5.6k     4.9k     4.5k     4.4k     4.6k     4.4k     4.3k     4.4k     4.6k     4.8k     5.5k     5.7k     5.6k     6.2k     8.7k     7k       5k       Uni Avg
MILES           223.7k   207.9k   191.9k   182.2k   177.7k   173.3k   164.8k   156.8k   152.5k   148.1k   143.5k   138.7k   133.2k   128k     121.9k   115.7k   107k     95k             
SAMPLE TAKEN    8/31/14  4/27/12  3/19/10  7/26/09  4/19/09  1/23/09  8/2/08   2/9/08   10/27/07 7/21/07  4/7/07   1/6/07   9/2/06   5/7/06   1/7/06   8/21/05  2/28/05  6/6/04          
                                                                                                                                                                                         
ALUMINUM        3        4        2        3        2        3        2        3        2        3        4        3        2        2        3        2        2        2        3      
CHROMIUM        0        1        1        0        0        1        1        1        0        1        1        1        0        1        1        1        1        1        1      
IRON            50       34       11       8        9        13       12       14       12       17       24       19       14       16       22       18       17       13       14     
COPPER          13       13       11       15       9        12       12       14       14       13       12       14       14       13       15       17       13       16       18     
LEAD            9        11       5        5        4        8        18       14       22       19       10       14       28       11       23       42       5        5        7      
TIN             0        0        0        0        1        1        0        2        0        0        0        0        1        0        0        1        2        1        1      
MOLYBDENUM      54       47       53       54       53       50       3        2        6        18       91       84       82       72       85       77       60       70       41     
NICKEL          0        1        1        1        0        1        1        1        0        1        1        2        0        0        1        0        0        1        0      
MANGANESE       1        1        1        2        0        0        1        0        0        0        0        1        1        0        0        0        0        0        0      
SILVER          0        0        0        0        0        0        0        0        0        0        0        0        0        0        0        0        0        0        0      
TITANIUM        0        0        0        0        0        0        0        0        0        0        0        0        0        0        0        0        0        0        0      
POTASSIUM       9        9        8        12       17       22       9        16       6        10       20       9        6        6        11       17       11       7        7      
BORON           3        23       25       30       26       25       4        3        5        12       57       60       51       122      55       106      104      150      45     
SILICON         14       11       7        7        5        7        8        8        7        9        11       11       11       11       12       9        9        11       11     
SODIUM          31       42       39       26       36       48       23       35       19       24       46       20       6        9        10       14       12       19       11     
CALCIUM         2379     3076     3277     3026     3067     3267     2494     1896     1866     2013     2564     2308     2731     2294     2705     2780     2302     3134     2128   
MAGNESIUM       17       16       17       22       34       131      593      563      525      424      20       15       14       19       19       19       25       23       131    
PHOSPHORUS      698      656      697      742      703      766      981      870      842      797      737      658      673      698      677      745      592      831      741    
ZINC            874      759      915      979      870      1082     1251     1066     1082     1041     932      818      834      870      838      946      694      983      901    
BARIUM          0        0        0        0        0        0        0        0        0        0        0        0        0        0        0        0        0        0               
                                                                                                                                                                                         
                                                                                                                                                                                         
INSOLUBLES      0.1      0.3      0.3      0.3      0.3      0.3      0.3      0.3      0.4      0.3      0.3      0.3      0.3      0.3      0.3      0.4      0.4      0.5             
WATER           0        0        0        0        0        0        0        0        0        0        0        0        0        0        0        0        0.1      0               
FLASHPOINT ºF   400      405      390      420      400      385      405      415      415      395      405      395      390      370      395      425      385      375             
SUS VIS 210ºF   57.6     58       60.9     60.7     59.5     61       66.9     67.7     66.8     67.7     63.6     64.4     63.2     62.5     61.8     65.3     63       62.2            
cSt VIS 100°C   9.54     9.64     10.47    10.41    10.08    10.51    12.13    12.35    12.11    12.33    11.22    11.44    11.11    10.91    10.7     11.68    11.05    10.8            


* 4 qts M1 5w30 + 1 qt M1-EP 15w50

 

[dustyroads]

I don't know what to say. Your potassium and sodium levels both match up with a good long trend of analyses, no spike in those two. Not sure what happened with the iron. Your sodium level does not indicate previous use of an add-pack with sodium in it. After using an oil with 300-500 ppm of sodium, the residual is often well over 100 ppm in the next sample. Maybe your engine drains exceptionally well, but I doubt you used a sodium laced oil just before this run. (?) The silicon is slightly higher but not bad overall. I only see a jump in iron but don't know why.

 

[dustyroads]

Looking again, I see it was over two years and almost 16k since the last report. Maybe you had a large amount of iron built up from the coolant intrusion and you are seeing residual iron. Maybe your next sample's iron will come back down after another oci. I guess you may never have had any coolant intrusion? I just don't know.

 

[ATS-V]

I repaired the LIM gaskets and cheap Peak Oil was run for 500 miles. Then a fill of PP 5w30, then another PP 5w30 which is the sample above. Repair was done March 2013. Regarding your coolant intrusion comment, it was very, very minor that's the reason I never ripped into it until 2013. Whenever I saw external seepage I added GM seal tabs to keep it in check. It's hard to say, prior to 2010 this engine saw the same routine averaging 16k per year. Now it sees only 6k per year and lots of short trips which I believe is the source of the iron (many more cold starts per mile). All in all this engine doesn't owe me anything, it's one of the most trouble free engines I have ever owned. It still puts down good power and averages good mileage if I can say out of it (it has a few mods).

Originally Posted By: dustyroads

Looking again, I see it was over two years and almost 16k since the last report. Maybe you had a large amount of iron built up from the coolant intrusion and you are seeing residual iron. Maybe your next sample's iron will come back down after another oci. I guess you may never have had any coolant intrusion? I just don't know.

 

[dustyroads]

The short trips make sense for the rise in iron. I thought maybe your oil was getting contaminated and causing iron to go higher but short tripping and cold starts sounds plausible. My dad's 5.3 had a couple real ugly reports from super short trips and many cold starts.