The Stovebolt Site Forums The Shop Area Engine Shop 4.3 GM engine

Would like some pros and cons on the 4.3 engine used in some S10s and other GM vehicles, tks

thats the good v6....got 150,000 miles on my s10 with no probs other than starter n alternator..

Roger
We have a 93 S10 with a 4.3 It has been a very depandable truck and is cheap to operate. It gets about 25 miles to the gallon on the highway and about 17 around town. There are lots of them around here, and they just seem to keep going.
Jim

It's a good engine, it's based on the 350 Chevy so there aren't any suprises. I have heard some people complain about vibration, but I personaly haven't noticed anything excessive. Some 90's engines had a balance shaft in the lifter gallery, I don't know how much difference it really makes. Hope this helps.

Sean

Had one in a 02 Jimmy and now one in my 03 Safari. The Jimmy ran well up until we traded it in for a new Vibe. The one in my Safari also has been reliable and runs well(80k with no problems) and has plenty of power but they both got crappy mileage. The Jimmy between 15 - 19mpg and the van gets about 12 - 13mpg. My C-10 w/235 gets between 16 and 20 depending on my foot. The Vibe gets between 32 and 38 and is faster than all of them.

Had one last year, a 91 with 202k and ran like new. No lifter or valve train noise of any kind. Did not burn oil and got about 17 mpg general driving city and some highway. In the 20s on the highway. It was TBI which has less problems than port injection. I have owned both. Cheaper than port to fix too. Cost me $600 for the central port injector and the fuel rails. TBI is much less and less sensors to mess with. Wished I kept that red 91. Will buy another in a month or so I hope and will keep it. 92 was the last TBI. Very reliable! Just a proven design like the 350 its bigger cousin. H.

How far back would I have to go to get a 4.3 that is not electronic?

Thank you one and all. What a great site!!

If you are going to put it in an older truck you can run without the injection if you want. Edelbrock had a carburated manifold for the 4.3. Hope this helps.

Sean

FI cam in in 86 or so in trucks. Earlier cars we carbed, better of buying TBI motor and using Edelbrock parts.
It's a 350 chevy with the front 2 holes missing, and some other subtle differences (like not all the expected parts interchange). Very reliable to 200k with maintenance. When they get tired, the RF cylinder is usually too egg shaped to bore, so they throw them away. Which is why rebuilds are more than a 350. Super good engine.

Thanks for all your input, what a great site we have here!!

Another example of great minds crawling in the same gutter! I'm trying to decide between a late model 250 or 292, SBC, or a 4.3 V-6. The information I have seen so far on the 4.3L is making it look better and better, but I am another one who doesn't want a computer controlled vehicle, even though I'm sure a computer can do a better job than I can.

I was thinking about the Edelbrock carburetor setup, but TBI is starting to sound interesting. How hard are they to hook up? What sensors are required? I assume they use an ECU. How expensive are they?

Ridgeview and Starkweatherr,

I would also chime in with my support of the 4.3 V-6. Great engine!

To that I would add, don't overlook Marine/boat dealers/scrap yards etc. when looking for applicable parts. There are alot of these 4.3 that are, or have been used in boats.

Besides another possible parts source, most of these units will provide you with the power plant w/out the additional automotive computer stuff.

They use both, a carb and TBI set-up on the marine applications.

Don't know how the horsepower translates, but the ratings of the marine engines are 190 HP for the carb, and 215 for the TBI.

Lastly, as others have stated, they're very economical to run. I can run my boat hard for at least 2-weekends on one tank of gas.

Had a 4.3 in a 96 1/2 ton with a 5 speed. Excellent mileage. 20 plus. Sold it to one of my sons at 162K. Used no oil and was super dependable with routine maintenance. Now pushing 200K with no problems. Now have an 06 1/2 ton with a 4.3 but with an automatic and mileage is down to 16/17. This is in my opinion one of the best engines I have ever owned. I think it would be an excellent replacement engine for an AD truck. Weeds

there are two 4.3s in the local trading post.it seems to me that 305s or 4.3s with overdrive would the best gas mileage engines for a pickup.

4.3s are just a great engine. Starkweatherr, if you want real torque and simplicity the 292 is the ticket. If you are going to pull ocassionally its still the way to go. A 250 is better on fuel and a diehard. Can be set up to put out some real HP. On a 2wd the 4.3 is an oustanding engine. Got good mileage with my 91 Bravada and my 91 S-10 Blazer. Had a 94 Bravada with the 4.3L H.O. and it was fast but used more fuel. It was good at first but something went out. The balance shaft makes it smooth like an 8. Some TBIs had them. I would love another 91-92 S-10 Blazer with the balance shaft again. The "vibration" that some talk about is because it is a large bore six in a V configuration with 9:1 compression ratio and the firing order also does this so it feels similar to the old Buick 225 V6. Perfectly normal. 4.3s are called the 300,000 mile motor by some. Those that got bad mileage is usually because the MAP sensor was bad or the O2 sensor or a plugged converter or some other sensor bad or a heavy foot. They went back to an updated TBI in 96 and got rid of the CPFI which had too many problems. The TBIs run forever! Also oxygenated gas will take away 3 mpg on the average. Thats what I lost on my 350 I have. That stuff is CRAP! Doesn't really help as we are told. They don't sell it over seas....just here in the States and in the winter here in Oregon up in Portland and part of the Rogue Valley only. Calif....all the time. A tid bit...there's someone in the midwest running an inline Chevy six, not sure which one, but from a lifetime Inliner member up north from me said some guy is turning the quarter mile in the 7s! Most 8s won't do that. Check out www.t6racing.com Download the video. Very interesting. He's running 250 bored .030 over with dual quads and he is putting a 604 cam in the new one. Ran this one for 17 years without a rebuild. Good ole' American iron!

I've had 2 of these engines and am more impressed about the power than the mileage. And btw, I'm currently having troubles with the 4.3 in my van. It was running like crap and the check engine light has been on and off. I took it to the dealership to check it out. They wanted over $500 for a tune up which they recommend at 100k miles. I declined that(I have 75k miles) and went with the replacement of the mass air flow sensor since that what their code reader said was wrong. I'm kicking myself for not doing my homework and doing it myself. That cost $575. I've had the van back for a day and it's still running like crap and the service engine light is still coming on. Tomorrow, I'm buying my own code reader and Chilton manual, and will shop around for parts from now on. At least this is only the 1st time I've had trouble.

i had a 84 it had a carb and no sead me this crap

I bought a new 1989 GMC with 5 speed and 4.3 V-6, gave it to my son to run my construction work in 1990, he kept it until 2003 when it was totalled by a semi (head on collision) and had over 400,000 miles still running good. The 4.3 is a bulletproof engine! It always got over 20 mpg. Daughter had a 1994 S-10 Blazer with 4.3 and 700R4 trans. It would almost stay up with my 350 V-8 GMC shortbed up to 80 mph. To say the least, I am impressed with the 4.3 engine it's one of the best to come out of Detroit ever.

A BIG AMEN on the 4.3. Getting ready to shop for one here real soon. Hey Bigmacdaddy, a suggestion on your van, you might want to replace the EGR valve. The intake in the EGR could be plugged up with carbon. Should come up on the reader but doesn't always. If they are bad it will run like crap and use more fuel. Makes teh light come on and off. Not sure what year you have. If its the CPFI you probably have fuel rails leaking like mine did and the fuel pressure regulator in the plenum was squirting gas. Had a bunch of gas inside the manifold. Ran like crap till I fixed it. Cost a bunch but did the work myself. Ran like a scaulded hound after that. What year is it? H.

2003

I was really surprised at the torque the 292 produces. V-8s smaller than a 350 couldn't match it. My only problem with the 250 is that one front head bolt that Leo Santucci mentions in his book. I'm leaning towards the 4.3L more and more after reading the comments here. I realize it is as wide as an SBC but does that mean that it is hard to get to the exhaust manifolds or spark plugs when one is in a 47-53?