Eight years ago I purchased my used 1995 Chev Blazer, it has 75,000 km
and just off a two year lease. It now has 526,000 km and has given no
trouble what so ever. I change the oil and filter every 5,000 km, this
gives the life to any engine and I mean it. It runs smooth, if you
watch what type of gas you put in it. At 500,000 km I treated it to a
new set of spark plugs and wires. The old plugs were worn a bit but no
sign of engine problems were indicated on the plugs. I have read that
some think the 4.3 L engine is the worst thing ever invented. I guess
I have the "one" that will give good performance for a long time to
come yet, I hope. Perhaps those who do not have very good luck with
their vehicles are the ones who abuse them.
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There is nothing wrong with a 4.3 as it is based on the long proven
350 and has not design defects to impair long life. I think most how
complain about them over work them with big tires with stock gears or
big loads with improper gearing. As you discovered that 4.3 can be a
workhorse with cared for properly. I would suggest that you might stop
using 5w30 in it except in very cold weather (use 10w30) and in hot
weather try 15w40 as it will reduce oil consumption that may be
This wouldn't be a full size blazer would it? Anyway, the owner's
for my 95 S-10 4.3 says its ok to use 10-30, but not 10-40, or 20-50,
or any other grade oil. Except for straight 30w at temps above 40F.
That's news to me, I've always heard of the 4.3L referred to as a very tough
engine. It's only really major problem is that it's missing two cylinders.
You have to be trying pretty damn hard to kill 'em.
Probably not. To clarify, all the *older* mid '80s 5.7s and 4.3s had a real
bad problem with the valve guides getting larger as the valve stem moved
over time and the valve seals getting brittle and cracking thereby letting
oil drip into the cylinders that were left open after the engine was shut
off. They were real oil burners. Largely by '89, GM fixed that problem but
for some reason only the 4.3 is really remembered for that problem.
My '90 305 still has that issue, and I've recently been told my '91 4.3L
puffs a little on startup too (must be new, it never had before.). Seeing as
how it only puffs for a few seconds at startup while the seals swell up and
that it's reasonably easy to repair on an sbc I really don't see it as a
reason to condemn the engine as a whole.
My 91 started burning a bit of oil on start-up around 130K but replaced
it with a rebuilt around 155K....My only complaint: lack of power on
hills, but it goes great on the flats (about 18-20 mpg on the piss poor
crap Calif calls "gas")
Oh yeah, the piston slappin' went away too
On my previous motor, a valve stuck (130K), punching a hole in a piston
(granted a smallish one) and I was able to limp 70 miles home with little
problem. Sure it ran rough, but it got me there. I went the easy route and
put a new (crate from GM) 4.3, but I thought long and hard of doing the 350
Yeah, I realize what causes a stuck valve. In my case it was the old bugger
who owned the truck before me and was a bit abusive to it. I wasn't
considering the 350 swap to avoid the valve problem. I was considering it
because it wasn't a whole lot more work or money for a lot more power.
That's good to know. I just bought a '97 Jimmy with 325,000 km on it.
I was leary because of the high mileage but I knew where it was coming
from, and it was a great deal so I decided to get it.
ok, I seem people refering to the metric system a lot, and I feel stupid not
knowing. But as to comment on other post's in the disscussion, the 4.3 is a
damn good engine, I have an S-10 with a 4.3, only thing ever wrong with the
truck is the O2 sensors constantly give me problems, either low input, too
high of voltage, and currently, all 4 sensors, banks 1 and 2 are reading too
rich of a mixture. This is a new code for my truck, but I have had so many
problems with those O2 sensors, and they ahve been replaced so many times,
its getting old now, its like the plauge of O2 sensors. I can't seem to
shake the problem, they will be fine for quite a long time, then start
acting screwy. I wish I knew what was causeing this problem.
My last Silverado had the 4.3 in it and it would chirp the tires easily...
it had nearly 300,000 on it when it was totaled by a guy coming off the
highway (yah, it was as bad is it sounds). The only problems that engine
had was the blow-by was so bad that it actually shot oil mist into the PCV
and then the mist got sucked into the carb. I had to extend the PCV valve
out a few inches from the valvecover to correct it. The other problem was
really not the engine, but rather the Q-Jet carb. The damn air bleeds would
adjust themselves out over time. (The Silverado was an '86)
a good valvecover cleaning now and again will help that problem with
the blowby. MMO or Lucas seemed to help as well <the cleaning aspect of
it>. A good synth oil will probably prevent the gumup of the covers to
Now my 4.3 story. I've had my Blazer since 99. <89 4.3, 700R4, NP231C
Tcase>. I bought it with 170K miles on it and it now has over 250K
miles <VSS is dead and I've not had time to troubleshoot>. I replaced
the motor in 2002 not because it needed it but because it was leaking
oil badly out the rear main <I thought-- turned out to be the valve
covers> and to my mind it made sense if I was going to pull the motor
to reseal the RMS and all other seals, to go ahead and replace the
motor. She ran like a scalded rat even at that mileage, with the oil
leak problem. I removed the intake and rocker covers to find the motor
absolutely CAKED with carbon sludge form the abse of the previous
owner. Even with it being that bad off, it still got me to work every
single day without a single problem, and gave me 15MPG city.
4.3 is a fantastic motor. I'm considering replacing mine <20K on it>
with a 350 after I do my SAS <sooooon!> for the extra grunt for
trailering my Jeep. If I do, the 4.3 is going straight to my built-up
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