I received the following question about a 2007 Ford Mustang V6 engine noise discovered after changing having his oil changed.
Hi Jeese
thank for you information, I reed you web site realy help me.
I looking for oil information because recently i bought a 2007 ford mustang V6, I change the oil in pep boys
i request to put 5-30w Mobil 1 Syntetic and engine star to sound like diesel until get warm.
what do you think it happen?
ALejandro
Reply,
Alejandro,
Was this your first oil change since you bought the car? Do you know what grade of oil was in it before?
The mobil synthetic may be a little thinner than the previous oil when it is cold. I’m guessing you are hearing some valve train noise.
It is hard to say what is happening for sure but changing your oil to mobil 1 shouldn’t hurt your engine.
Jesse
Further comments:
I mention the oil is thinner when it is cold when he starts the engine. The oil is still much thicker than it will be at running temperature and when it falls within its 30wt viscosity when it is hot. I have heard and read of this happening with a change to Mobil 1 synthetic oil. It is generally regarded as not harmful to the engine.
I have noticed that when people change from a conventional oil to synthetic oil they seem to listen to their engine very closely after the oil change. My recommendation is to have a good listen to your engine when you start it cold before you change your oil… then listen to it after you change your oil.
It is a strange human psychology that causes us to expand on issues after we place our focus on them. For example if you stop right now and think about your left foot you will notice that it is slightly uncomfortable in your shoe. After you notice it you have to put some effort in to not think about it anymore. One way is to try and remember your first phone number then say it backwards. Now think about your first girlfriend… (shouldn’t be thinking about your foot anymore.
We tend to identify what does not seem right when we focus on our engine sounds so be sure and listen to your engine before and then after.
I have worked with some other engineers that have performed noise testing on their diesel pickups and documented decreased noise when converted from conventional motor oil to synthetic motor oil. Those tests were conducted with AMSOIL not to be confused with the Mobil 1 comments above.
With all that said DO NOT ignore abnormal noises from under the hood. You and I are part of special group of people that are aware of our engines and have a good understanding of how they work (or maybe we did before computers!). Any change in the noise from your engine should be investigated until understood or deemed not harmful.
If you have any insight into Alejandro’s question please comment below. If you would like to find the best motor oil there is some great free test data in the report found here.
