Quick oil question

**stew215** · 03-27-2010, 03:03 PM

Well I changed my oil a few weeks back and some wierd noise started to come from the engine. I put in conventional oil and was wondering if synthetic oil would help this noise any. Well i have 6 quarts of mobile one in my garage and my local stores don't have the correct filter.

Well my question is... Would it be safe/ok if I changed the oil but left the filter since it only has around 100 miles on it? I am just unsure if it is ok to mix the synthetic with the left over conventional that will be in the filter?

-Thanks

**pajeff02** · 03-27-2010, 03:06 PM

Generally speaking, changing oil is not going to make a noise go away no matter what you use. What kind of noise do you have?

**stew215** · 03-27-2010, 03:11 PM

sounds like a lifter ... I also think the previous owner had synthetic in it and would like to change it back anyway.

**pajeff02** · 03-27-2010, 03:12 PM

Does the noise fade out as the engine warms up?

**stew215** · 03-27-2010, 03:15 PM

Nope and I also have the piston slap on start up so I know its not that.

**Senator** · 03-27-2010, 03:18 PM

If you had a missed shift recently, you may be dealing with a bent pushrod. The stock ones tend to bend right at or slightly above 6000 rpm.

If that is your problem, don't just replace your pushrods with hardened ones - get heavier valvesprings to go with the hardened pushrods, or replace the bent one(s) with stock pushrods. Better to bend a pushrod than to poke a hole in your piston.

HTH

Darden

**stew215** · 03-27-2010, 03:21 PM

The car is an automatic and have not hit the limiter

**pajeff02** · 03-27-2010, 05:07 PM

Could be a rocker went south on you. It's not too difficult to remove the coil packs and take off the covers to check things out.

**stew215** · 03-27-2010, 06:19 PM

I posted this vid before but here it is again ... I would like to do the oil tomorrow morning so does anyone know if it would be ok to mix the synthetic with the conventional that would be left in the oil filter?

[ame]http://www.youtube.com/watch?v=Co_U9kwXzc0[/ame]

**pajeff02** · 03-27-2010, 06:35 PM

I don't see any harm in mixing the oil, especially with as small as our filters are. To some extent, that happens anyway when you switch from one oil to the other.

**stew215** · 03-27-2010, 06:37 PM

Thanks for all the help! Did our cars come from the factory with synthetic?

**squirlnutz** · 03-28-2010, 05:59 AM

5-w30 mobil1 synthetic for ALL LS engines. You can use any brand you like, but 5w30, synthetic oil should always be used. The biggest problem with our cars, is fools use the wrong oil, like 10w30. Its too thick, pumps up the lifter too much, especialy cold. Thats the main reason our engines make lifter noise. The engine, is enginerd to use specific oil, just like the owners manuel says.