Oil for 1995 GMC 5.7L

[01F450]

I have been running Schaeffer 7000 10w30 oil in my 95 GMC 5.7L truck for the last couple oil changes. I am about ready to change the oil again. I have about 3K miles on the current oil but the engine seems to not be running quite as smooth as when I first changed the oil so I am thinking of changing the oil again. Last change was around 4-5 months ago. I drive around 6-7.5K miles per year. Is this decent oil for the engine I have and also for the number of miles I drive annually? The truck has 166K miles.

Also, I had the heads pulled a year and a half ago due to needing replacement gaskets. The mechanic said there was a lot of oil sludge in the engine. He cleaned it up as much as he could. I was not sure if this could be caused by the type of oil I am running. I was running Amsoil series-3000 prior to Schaeffer.

Thanks.

 

[beast3300]

Since you drive 6k-7500 miles a year then maybe something alittle less expensive would work. Maxlife 5w30, or Pennzoil conventional would do well for 6 month changes.

 

[S2500Dog]

Try a synthetic blend for you applicatio such as Motorcraft, Vavloline Maxlife, Pennzoil Gold, Quakerstate Enchanced Durability, or Mobil Clean 7500, Shell Rotella T5 (SM/GF-4 rated). Use an quality oil filter such as K&N, Mobil 1, Purolator, Wix, Napa, Non-Ecore STP or AC Delco filers.

 

[J. A. Rizzo]

I doubt the oil has anything to do with the way the engine is running, but if it makes you feel better...

The Schaeffer's is probably fine. Their products are good, in my experience. If the API spec for that engine is SL, you might want to consider an API SL or a high mileage or HDEO formulation. Maxlife, Rotella/Delo/Delvac, etc. It will probably be cheaper than the Schaeffer's too, unless you go with the synthetics like Maxlife syn or Rotella T6, etc.

 

[salesrep]

Schaeffers oil will work great for you. Chantge it once a year and sleep well.

 

[Rob_Roy]

How long have you owned the vehicle? The 5.7 is not known for sludge problems, I suspect it was neglected before you owned it or there is/was a PCV problem. The Schaeffer's 10w30 should work well for an annual change. Ask your retailer/rep. for some of their UOA kits, they are very affordably priced.

 

[01F450]

Originally Posted By: Rob_Roy
How long have you owned the vehicle? The 5.7 is not known for sludge problems, I suspect it was neglected before you owned it or there is/was a PCV problem. The Schaeffer's 10w30 should work well for an annual change. Ask your retailer/rep. for some of their UOA kits, they are very affordably priced.


I have had it since 1999. I had the heads pulled once before the most recent time due to broken exhaust manifold bolt, which was probably 9 years or so ago and back then there was sludge in the engine also. I have tried running engine cleaner through quite a few times in the past, before I change the oil in each case but I am not sure how much if any difference that made.

I will take a look at the PCV and also the UOA kit. Thanks for the info.