Hi guys.... I'm the proud owner of 98 Deville and I've always used Mobil1 High Mileage 10w-30....my mechanic said if I used Mobil1 15-50 that it would help with the oil leak that all northstars seem to have.... any input on that notion????
I agree that he gave you bad advice. There are plenty of owners on this forum with high mileage N*'s that don't leak a drop. Mine doesn't. Could it be he just didn't know how to do the repair, or didn't want to?that all northstars seem to have.... ????
the 15w50 Mobil 1 V-Twin variety worked really well in my 98CI Yamaha Roadstar.15w-50? :shocked2: That stuff should be approaching gear lube viscosity when it heats up. I'm sure it WOULD stop leaking. :tisk:
LOL... Until a rod comes through the block, but won't leak long.I hear that 85W-140 gear oil never leaks in a Northstar. :tisk::tisk::tisk::banghead:
Aside from the leak sealing guesswork, the oil use advice is mostly fact, not opinion. 15W-40 and 15W-50 oils are reserved for some really heavy duty commercial engines as well as air-cooled motorcycle engines. The research ship that I captained for 12 years had four twin turbo Cummins V-12 diesels, 720 hp each. Those engines used Drydene 15W-40 oil and had a 3,000 hour overhaul interval. 15 gallon sumps.Well after considering ur opinions.... I stayed with my gm recommended 10-30...thanks guys... y'all r awesome
:histeric:Z71 said:Mechanics and engine oils are like Police and radios, they know how to use them but they don't know how they work.
Bearing clearance is the key. You can run thicker oil in old engines with big clearances but not in a Northstar with tight clearances. Very bad advice from the very old school mechanic.My MGB's used the heavest weight of any of my other cars at 20W-50. The MG's engine was built with big clearences.
I also used to use Aeroshell 100 (50 weight) in my 1951 M38 Jeep but that was because it would sit for extended periods of time and the Aeroshell would stay in the bearings and oil pump better than anything i found. (kept the dry starts at bay) But i was verry carefull how i ran it and never loaded it cold. The Willys also had big clearences. I would not recomend this to anyone else.