94 Engine Question

[Xbox2202]

Ok, my dad has a 94 Chevy Van 20, and I'm pretty sure that it has the same engine as the Blazers of the same year, so I figured that you guys would know about this.

So, he has a V6 in the van, and as I said before, I think it's the same as the Blazer engine, correct me if I'm wrong. Anyways, what weight engine oil would it take?

He said that he thought that the manual said 5W 30, but that seems pretty light considering that my Camaro takes 5W 30.

[mrfirebird]

5-30 is what the fill cap says on our 94

[Mikado14]

The manual was correct. The 4.3 vortec, either W or Z is 5W-30. I don't use this but that is what the manual says. I have a '93 s10 with the 4.3 vortec and have never run that grade of oil. Last compression check (for sh*ts and grins) was 8k miles ago and all 6 were the same as they were the first time I checked at 100k mi. Oh, the current mileage is 192K.

[BlazerLT]

Wow, good going?

Were they around 150?

BTW, yea, 5W30 is the oil for your truck and you can use 10e30 if you don't get cold temperatures in your area.

[Mikado14]

BlazerLT, had to go look up the numbers, my mind just wanders at times, here they are: #1-162, #2-156, #3-165, #4-155, #5-160, #6-162. I measured these with a Snap-On compression guage with a nice big dial face(haha), I didn't need my other eyes. The original numbers weren't different other than a few pounds more. I have always run 10W30 in the winter and 10W40 in the summer. Also, about 4 years ago at about 140k miles I started using Lucas oil treatment. Oh, I also check my compression with the engine warm. Also, I live in Pennsylvania southeast around Philadelphia. Doesn't get too cold but not too hot either.

[BlazerLT]

Those number are practically showing you that your cylinders are still new which is awesome. Using 10w30 in the winter and 10w40 in the summer is not a bad idea but it is a little thicker than you really should be running for adequate top end lubrication.

How cold does it get in Pennsylvania?

[Mikado14]

Hey BlazerLT, yeah on those numbers. My boss didn't believe me until he saw it for himself. Anyway, I would say that the coldest it ever gets is maybe between 10 and 17 and that is at night time. Rarely does it fall below 20 during the day. And when it does get that cold it doesn't last. Usually it gets above freezing during the day. I think we only had a few days above 90 this summer. All things considered, it is pretty moderate as far as temps go. My belief is in the lucas oil treatment. My oil pressure increased after I put it in. It would idle at about 35 and after I put it in it went to 40. Going down the road at about 65mph it used to be about 60 but now is anywhere above 60 to 80 depending on rpm. If seen some tired engines brought back for a little more life with it.

[BlazerLT]

You are running too thick of oil bro.

You are getting good compression because of the thick viscosity which is good in one hand, but the higher restrictiojn may starve some vital components of their lubrication in the top end.

Consider going to a thinner oil.

5w30 in Winter w/ Lucas
10w30 in Summer w Lucas

Trust me, you need to take care of this, these oil pressure numbers are not good for a 4.3L. Seals will wear and pop prematurely.