Oil for old Chevy TBI 350

[maxdustington]

GMT400 burb top-5 truck for me.

I like the old interior more than the new one, nice burb. Had a 95 when I was a kid, oh the memories.

 

[Duffyjr]

I don't know about Idaho but here in Nebraska we've been seeing a lot colder temps the last few winters so I moved to 5w30 in the winter for my 89. Been changing it in the summer to a 10w30 but this is my last run of the VR1 10w30 and twice a year changes. Moving forward with annual changes using 5w30, probably Valvoline Daily Protection or Advanced.

 

[GR_CoB]

When I used 5w30 in my 350 TBI - it had low oil pressure after long idle (10+ minutes). Moved up to 10w30 and thicker, no low oil pressure issues ever since. With Delo 5w40 it sits 40 psi idle and 70psi on start. Normal driving 40-60psi depending on RPMs.

 

[dave1251]

Originally Posted by Vladiator
When I used 5w30 in my 350 TBI - it had low oil pressure after long idle (10+ minutes). Moved up to 10w30 and thicker, no low oil pressure issues ever since. With Delo 5w40 it sits 40 psi idle and 70psi on start. Normal driving 40-60psi depending on RPMs.


Funny considering in ISLAC grades 10W30's tend to be thinner than 5W30's.

 

[joemo]

Wife had dodge 2.7 called for 10w30. Oil change place put 5w30 oil light stayed on at idol.when we saw this we checked sticker made them change to 10w30.drove to Florida .drove several years no oil related problem.

 

[GR_CoB]

Originally Posted by dave1251
Originally Posted by Vladiator
When I used 5w30 in my 350 TBI - it had low oil pressure after long idle (10+ minutes). Moved up to 10w30 and thicker, no low oil pressure issues ever since. With Delo 5w40 it sits 40 psi idle and 70psi on start. Normal driving 40-60psi depending on RPMs.


Funny considering in ISLAC grades 10W30's tend to be thinner than 5W30's.

Does this apply to all 10w30 vs 5w30, or just cherry picked examples here and there? They're both 30 grades, which ranges from 9.3cst to 12.4cst at 100°C, I believe... So what you're saying does make sense. Just wondering if that is a rule of thumb, or just "Brand A 5w30 vs Brand B 10w30" type of thing...

 

[Greg L]

I had the same 350 engine with 460LE transmission in my 1996 GMC. Great motor.

It had 220k miles when I sold it, and was still running great. With that many miles, check to see also when the spark plugs were replaced.

My engine always seemed to like 5w30 or 10w30, in Mobil 1 High Mileage, Valvoline MaxLife, and Castrol High Mileage. (in that order)


Also have your transmission looked at, if it is the 460LE. Mine started to act up with high miles & you may need to drain the transmission fluid & replace a screen. If it shifts erratically, you may need to also replace the Solenoid board inside the transmission...which rebuilt ones can run from about $80 bucks to $300.


GL