Hi all—new here to the forums. I'm looking at purchasing my first blazer, a 2004 LS 2WD with 130k miles on a 4.3L V6. I've been doing extensive research online to gather all necessary info on common problems, things to look for, do's & dont's, etc. Thought I would check in here with the community.

Is 2004 a good year? What common issues should I be looking/asking about when purchasing?

Thanks for all the info in advance!

 

I believe there is a "sticky" thread on known common Blazer problems.

I'm not familiar with the 2wd versions so bear with me.

Two issues that could apply to you are the failure of the lower intake manifold (LIM) gaskets that can allow water to leak directly into the lifter valley. However, I suspect that this issue was more with the late 90s Blazers. When these gaskets failed, the engine could be ruined in less than a minute.

If a Blazer has a remote oil filter, the hoses can leak and so the o-ring between the engine block and the adapter to which the hoses attach. This is more an of annoyance.

The 4.3L can last a long time if the oil was changed regularly.

The plugs, wires, rotor and cap should be replaced at about 100k miles. For the rotor and cap, only use GM parts.

The 4L60E has some not uncommon failure mechanisms. But if the truck was never used for towing and the transmission was never allowed to overheat, which would happen while towing and especially while towing in overdrive, then the 3/4 clutch pack can slip. The only way to fix it is to have the transmission rebuilt.

I'm pretty sure the 2004 was the last full year for these with the 2005s being when the last of them were sold. As such, there is almost 10 years of the second generation Blazers the preceded the 2004 so that one would hope all the bugs would have been worked out.

Hope this helps.

 

I'm not terribly knowledgeable with blazers, (yet!) but I do have an 04 RWD.

There's gonna be the basic "used car tests." You know, drive it around, get it up to highway speed, test the lights and blinkers and radio, test the brakes, see how straight it drives with your hands off the wheels... But you probably know that already.

Blazer specifics:

Intake gaskets are probably the most likely thing to ruin your day.

Mine still has original ball joints, shocks, and bushings, and they're getting replaced at 54k miles because the bushings are all dry rotted and cracked, (thanks Florida lol) and 2 ball joints are leaking all their grease. So check suspension and steering.

My AC needed a fair amount of new parts. (Compressor, valves, and... The silver cylinder thing, whatever that is lol) Blast that AC, and the heat too. Make sure it works.

Before you crank it and get the engine to warm, pop off the radiator cap and check if the coolant has turned to sludge or not. If the fluid doesn't go to the top of the radiator, it's low.

Oh, and check under the driver and passenger floor mats for any dampness. The heater cores can leak your coolant on to the floor.

Make sure your heat/cold temp **** works. The blender doors sometimes don't work. Also check the vent direction blower **** thing. (You know, defrost, lower vent, front vent...)

Aside from that, it's mostly little things that you wouldn't think of, like...

My windshield washer pump looked like someone bent it over their knee. Found out it leaked after I filled it with washer fluid. Still pumped fluid, though!

My belt was from 2009. (In 2023) Replaced that one quick!

My belt tensioner had a bad bearing. (Replaced with belt.)

Oh, and I don't think 04 is worse than any other year. If anything, things like radio swaps become easier. But I'm biased, having an 04 lol!

 

Thank you! This is helpful for sure. Going to check out the car tomorrow. Will report back!