1998 GMC Jimmy, switching wts?

[otis24]

I just purchased a 1998 GMC Jimmy with 4.3 liter V6 engine from the dealership where I work. I called the previous owner and am relieved to know that he is the original owner. The vehicle has 114K miles. It is spec'd for 5W/30. The previous owner stated that he used 15W/40 in this engine.
The dealership changed the oil when we received the vehicle in trade using GM 5W/30 (Mobil). Will switching to 5W/30 present any issues? I plan on adding a bottle of Auto-Rx when my shipment arrives in a few days.

 

[Chris142]

No problem at all. My boss has a 1996 Blazer with the 4.3. It's coming up on 300K. It's had a diet mostly of Pep Boys Proline oil. When it started to use oil I began running 10w-40 in it and will be going with 15w-40 soon.

 

[rg200amp]

No proplems. The Spec'd oil will work great in that engine. Thus its spec'd.


You should get many more years out of it.