What Oil Weight and Capacity to use for 3.4l?
 

So Ijust picked upan 84 blazer with a 3.4l v6 swap a little while back. It's time for the first oil change, and I can't figure out how much, like what's the capacity? The engine has about 80k miles on it now, and the last oil change sticker on the windshield said 20w-50 was used. Should I stick with that weight or switch to something different? I live in the mojave desert....in the 110's for highs in the summer and down almost to freezing on winter nights. Just want to use the best weight that I can! Any recommended brands would be good too!

Also, what kind of spark plugs does this thing take? I think it has just some basic autolight coppers right now, they look past due for a changing. Which model should I get? thanks for the help!

RE: What Oil Weight and Capacity to use for 3.4l?
 

Mind you, this is just my opinion....
but also keep in mind that I too live on a High Desert, with like temperature ranges.

During the winter I run 10w40
During the summer I run 20w50

considering the relatively low miles on your vehicle you might consider 5w40 during the winter months which is actually what is recomended IIRC.

Full Synth

as for the sparkplugs, AC Delcos


and the Highs here this last summer hit 128 F

RE: What Oil Weight and Capacity to use for 3.4l?
 

Dang, luckily it doesn't get that hot here! I wasn't sure if it'd be better to run a thicker oil like 20w-50 in the summer or not. I was thinking about maybe going down to 10w-30 for a thinner oil. I'll have to check in to that heat stuff. I think I'm going to stick to conventional oil also, just cause I don't want to start a bunch of new leaks switching over at this high of mileage.

Do you happen to know what model of AC delcos you run? I'm not sure if spark plugs for the 2.8l and 3.4l are the exact same or not, do you know? Just cause I don't know what kind of car the 3.4 came out of, so it's hard to search for! Thanks.

RE: What Oil Weight and Capacity to use for 3.4l?
 

Bump, anybody?

RE: What Oil Weight and Capacity to use for 3.4l?
 

Considering that it is pretty much the same motor as the 2.8L that was in there, you can stick with what was recommended for that engine. 10w30 was the likely recommended weight of oil for the 2.8L.

The same is true for the plugs considering that it is the same ignition system as well.

RE: What Oil Weight and Capacity to use for 3.4l?
 

Cool, thanks. Yeah, just bought the vehicle and I'm not too sure what's compatible between 2.8 and 3.4l. And I don't know what car the engine is out of, so it'shard finding parts. Can I pretty much plan on everything being compatible? Like, should I just say I have a 1984 2.8l when I'm searching for parts like plugs, plug wires, oil filter, air filter, headers, exhaust, etc. Just want to make sure all the parts will fit, thanks!

RE: What Oil Weight and Capacity to use for 3.4l?
 

The longitudinal version of the 3.4L was used in both GM and Jeep (yes, Jeep) vehicles from that time period. Here's some info on the engine.

RE: What Oil Weight and Capacity to use for 3.4l?
 

Thanks for the link. So is it more than likely that this engine is out of a 93-95 camaro or firebird? The engine looks the exact same as all the 2.8l blazer engine bays that I see. I need to try and find a code or vin # on the engine somewhere.

RE: What Oil Weight and Capacity to use for 3.4l?
 

bump?

RE: What Oil Weight and Capacity to use for 3.4l?
 

What exactly are you trying to find out?