[420blazer03]

So I don’t know if this is a case of previous owner neglect or if this thing is inherently a POS, but heres all the problems my truck has. It is a 2003 blazer with the 4.3, rwd.

-makes a really crappy rattling sound in the 1100-2000 rpm range
-oil seeps out of near every gasket even though i changed them all (Ill blame myself for this one though) but interestingly never puddles underneath
-the harmonic balancer and crank pulley wobble very noticeably. I’ve read mixed things about this, Im inclined to believe the crankshaft is bent but how does such a thing even happen? It has good oil pressure, 55 psi on a cold start and 40 psi at hot idle
-coolant becomes contaminated with some strange oily substance. Idk if its oil or what but Ive flushed it a couple times now and it still does it, although a lot less.
-one or all wheels has a loud, cyclic clicking sound that increases with speed
-a lot of play in the steering, alignment is off, suspension makes a loud popping sound on tight turns
No check engine light, though and it runs great on the freeway, but taking off from a dead stop, it rattles like a maraca then stops once it hits 2k rpm and the harmonic balancer wobbles even after putting a new one. These are my biggest concerns. Is there anything I can do to address all these issues short of a full engine rebuild? Ive replaced everything bolted to the engine at this point, it’s ridiculous. The rattle seems to improve for a while after replacing certain parts then comes right back. Tired of it.

if i had the time and money Id tear out this POS motor and put in a 6.0 and 6l80e.

 

[Life is a Enigma]

The 2003 it's going to have It's issues. And for it leaking oil, that's normal for the typical 4.3 they like the piss out of every orifice and seem if possible. Just take your time and work on one piece at a time. Eventually you will get it to where you want it to be.

 

[Hoosier Rick]

When I was at the Chevy dealer, we had a customer complain of a wobbling balancer. Crankshaft did not have excessive runout, so we replaced the balancer. The new one was worse! We took the new one to a machine shop and had it trued up.

 

[PeteD]

So I don’t know if this is a case of previous owner neglect or if this thing is inherently a POS, but heres all the problems my truck has. It is a 2003 blazer with the 4.3, rwd.

-makes a really crappy rattling sound in the 1100-2000 rpm range
-oil seeps out of near every gasket even though i changed them all (Ill blame myself for this one though) but interestingly never puddles underneath
-the harmonic balancer and crank pulley wobble very noticeably. I’ve read mixed things about this, Im inclined to believe the crankshaft is bent but how does such a thing even happen? It has good oil pressure, 55 psi on a cold start and 40 psi at hot idle
-coolant becomes contaminated with some strange oily substance. Idk if its oil or what but Ive flushed it a couple times now and it still does it, although a lot less.
-one or all wheels has a loud, cyclic clicking sound that increases with speed
-a lot of play in the steering, alignment is off, suspension makes a loud popping sound on tight turns
No check engine light, though and it runs great on the freeway, but taking off from a dead stop, it rattles like a maraca then stops once it hits 2k rpm and the harmonic balancer wobbles even after putting a new one. These are my biggest concerns. Is there anything I can do to address all these issues short of a full engine rebuild? Ive replaced everything bolted to the engine at this point, it’s ridiculous. The rattle seems to improve for a while after replacing certain parts then comes right back. Tired of it.

if i had the time and money Id tear out this POS motor and put in a 6.0 and 6l80e.

Nothing that a few $$$ won't fix , no matter which solution you choose. If there's a nearby shop you think is reliable (& been in business a few decades) you might get an experienced diagnosis of issues stated. This to eliminate a blind decision.

 

[Lonelydriver95]

In my admittedly quite uneducated opinion I would put this down to neglect. I have a 00' LS 2.2 Manual that's been in my family since the early 2000s and this thing has been just about faultless for its whole life. I've personally owned it since Feb of 2020 and all that's gone wrong mechanically was a Throttle Position sensor. My brother also has a 99 Jimmy 4.3 4X4 with almost 280K that just refuses to die.

edit: I do have to confess to a leak in my front timing cover but I don't lose much oil because of it so ill just pretend its mint.

 

[MrUnknown]

I owned a 98 Blazer and currently a 2003 S10 both 4.3's and mine don't have these issues. The 4.3 is one of the most reliable V6 engines ever made and are typically capable of 300,000 miles if maintained.

Be sure to use quality gaskets and seals like Fel-Pro instead of the cheapest you can possibly find.

Aside from things like Dexcool, Lower Intake Gaskets, Valve Cover Gaskets, Oil Cooler lines there isn't really that much that goes wrong. Most 20+ year old vehicles are going to have a seeping oil pan gasket I usually just ignore it unless it is an active leak.

Sounds to me like you have a neglected Blazer. And also sounds like for the oily substance that your lower intake gaskets might be starting to seep a bit.

 

[SSandfish]

In my case, I bought a 2003 Blazer-X, 4.3 with 55k miles on it in April, 2019. When I bought it, the rear main and oil pan gaskets had bad leaks (and still do). Can't blame it in high mileage, but just age in general. It is 20 years old and gaskets fail. As far as reliability, my dad had this same engine in a GMC 1500 pickup and it had 450k on it when he finally got a new truck!

I would fix my Blazer, but I am not spending a dime on this since the entire drivetrain os getting pulled and sold in a few months

Agree with other replies. Fix it! This is standard maintanance (that the previous owner should have done) and when done, the repairs will last. These are pretty simple to work on and there os a lot of info on this forum. 👍

 

[MrUnknown]

In my case, I bought a 2003 Blazer-X, 4.3 with 55k miles on it in April, 2019. When I bought it, the rear main and oil pan gaskets had bad leaks (and still do). Can't blame it in high mileage, but just age in general. It is 20 years old and gaskets fail. As far as reliability, my dad had this same engine in a GMC 1500 pickup and it had 450k on it when he finally got a new truck!

I would fix my Blazer, but I am not spending a dime on this since the entire drivetrain os getting pulled and sold in a few months

Agree with other replies. Fix it! This is standard maintanance (that the previous owner should have done) and when done, the repairs will last. These are pretty simple to work on and there os a lot of info on this forum. 👍

I am not going to tell anyone to use the product or not but there is a product called AT-205 Reseal and the majority of people seem to have success with it stopping rear main seal leaks and plenty of videos demonstrating it.

I can't recommend against it or for it because I personally have not used it but it is something people can look into and decide for on their own.

 

[PeteD]

I am not going to tell anyone to use the product or not but there is a product called AT-205 Reseal and the majority of people seem to have success with it stopping rear main seal leaks and plenty of videos demonstrating it.

I can't recommend against it or for it because I personally have not used it but it is something people can look into and decide for on their own.

An ounce or two of dot 3 brake fluid to eng or trans oil can soften many types of seals , reducing or eliminating leaks. Give it 50-100 miles .

 

[PeteD]

An ounce or two of dot 3 brake fluid to eng or trans oil can soften many types of seals , reducing or eliminating leaks. Give it 50-100 miles .

Works on many Power steer seals too.