Engine oil

[Julio Meza Hamm]

Hello guys. I do have a question. For a GMC Sierra 97, owners manual said for engine oil I need to use 5w30 but my mechanic said my car its too told to use that oil and recommended me to use 15w40.

Can you help me out with this?

[newdude]

GM designed it to run 5w30 when they came out. Run 5w30.

[BoatRDavid]

My Chilton manual says SAE 5W-30 can be used from 100*F to -20*F and SAE 10W-30 can be used above 0*F.

[Black02Silverado]

5w-30 is just fine. I would say on average most of your trucks on the road today with high mileage are running 5w-30.

[Bill_N]

I've always run 10-30 in my '96

[diyer2]

IMO

Is the motor using a lot of oil?

There is enough miles on your motor that the tolerances have loosened up. Unless your in Alaska with regular cold temps 15W40 will be fine.

[TheImpalaMan]

How many miles on on this 97? If you haven't hit 200k, and the compression is still really good, I'd stay with 5 or 10w-30. However, if you are close to 200k, might be a good idea to change your timing chain set as well as your oil pump just to keep things fresh.

 

diyer2 has a good question...does the engine use/burn motor oil? If so, how much do you lose by the time of your next oil change?

 

-TheImpalaMan

[sdeeter19555]

What engine?

 

Sent from my SAMSUNG-SM-G900A using Tapatalk

[dreese_us]

Gas engine if it is using oil, 10w30. Use 15w40 if its a 6.5 diesel.

[Killain]

If General Motors built it and say 5W-30 then I think they know what to put in it. The whole "Heavier" oil ideas are really not good for a host of reasons, but the weight of a perticular oil that is in spec for an engine, the manufacture really does know what is best. I've seen all sort of shade tree mechanical theory, but the manufacturer is the best expert. No bad mouthing your mechanic, I'm 65 and I use to think the same way, but a 5w/30 is the best oil for your car. I own a 1988 Chevy Blazer with a 5.7 liter. The owners manual and it says to use 10W/30 for my particular area. So that is what I do, it's worked for the last 28 years so why would I think I'm a better expert than the company. I have a 1990 5.0 liter V8 in my 90 Silverado, it's owners manual says I need 5W/30, so that is what it gets. Both engines run summer and winter and are quiet and run excellent. I don't want to fix something not broke.

[barry G]

go by the book.

 

and synthetic hangs on way below zero.

 

the worst pat of any engine is cold start.

Maine does not have a pacific fog in its 20 below, or a warm continent beneath its feet, or an ice box queen.

 

That is all dead here. Died millions of years ago... to frostbite.

 

it gets so cold here, perforated mufflers clog to ice crystals sitting overnight, and paper element filters kick oil pressure reliefs wide open... that is equal to no filter at all.

it gets so cold, an idle mAF reading brings 8-10 mpg to the density of the air.

 

synthetic is awesome. the gmt400 is the first realm to be built to accept it.

 

you can use the crossover stuff too. that half and half oil.

 

oil too thick simply sounds like a drain back noise you could get on a hot summer day.. like sloppy rod noise or a lifter smacking for some seconds.

no big deal to go too thick..

I simply respect oem anyway.

[OceanSpray]

My 1990 5.7L C1500 calls for 5W-30. I switched to Mobile 1 High Mileage 5W-30 synthetic. At 105,000 miles, all is good.

[ifixedit]

Got a 98 Yukon with 220,000 on the clock, all it's ever seen is 5W-30 and only uses about a 1/2 quart to maybe a quart between changes of around 3000 miles.

 

Keep the 5W-30.

[Relisys190]

99 OBS Escalade with 235,000 on the odometer. I've always used Castrol 5w30 high milage for the last 10 years.