Hello all. This is my 1st post but I've been a visitor several times. Great resource.
I have a BIG PROBLEM with my 2004 Blazer, V-6/4.3L, 2 door/auto. 8 yrs old but low mileage @47,700. A leg injury has limited my driving so this has kept the miles down. I purchased the 6 yr/72,000mi extended warranty which does me no good now.
According to my mechanic I now have a 'money pit' on my hands because my cooling system is shot.
The radiator is gunked up & plugged, intake manifold is cracked, water pump is leaking & of course the coolant is very, very bad. He wouldn't repair it and told me to trade it in asap. Said the amount of gunk in radiator & thru out cooling system has most likely gotten into engine & is causing corrosion/damage there. Mechanics estimate was $1300. I'm in the process of getting a 2nd opinion. I realized there was a problem when the temp gage almost red lined last week, it went down when I ran the heater. it never over heated and never has. In fact it has never run hot until last week. My mechanic refilled the coolant (said it took 20 min. due to all the gunk in radiator) It's running good now but I heard a scary sounding rattle that lasted about 10 sec. when I started it for 1st time this morning.
I'm taking it to another mechanic today.

I am not sure what is best to do;repair it or trade it in. I've gone from being shocked and confused to angry & disgusted. This is not something that should happen to an engine with less than 50,000 miles that has been pretty well maintained. I haven't even had the brakes redone. Still using factory sets. I believe I have a lemon. Mechanic feels that something may have been done when the engine was very young or even in factory. Perhaps coolants were mixed in the radiator or 'stop leak' was added. I don't do much other than check the fluids to see if it all looks good.

I've learned that cracked intake manifolds are not uncommon in S-10 engines.
This is my 3rd Blazer. My first was a 1984 5 speed manual tran. I traded that in on 1999 beautiful black V-6, 4.3 that I drove until it died.. It was a great little SUV. Loved it! I traded it in on this one in 2004. My plans were to drive it until it quit too. Little did I know that might be before 50,000 miles. UGH!

I'll know more after tomorrow's 2nd opinion. I contacted Chevy but don't expect much from them.
Any input is appreciatted.
Thx everyone!

Xhatch in SoCal

 

The "issues" you're experiencing are not the fault of the vehicle. The cooling system must be maintained properly to avoid the trouble you're having. GM recommends a complete cooling system flush & fill with Dexcool coolant, (orange) every 5 years or 150K miles, (whichever comes first) however, in the real world to avoid problems, it needs to be flushed every 3 years or 50K miles. The vehicle is nearly 9 years old, and if it hasn't been maintained, it's to be expected that the system is clogged with sludge. If ethylene glycol coolant, (green) is added to the system, it will accelerate the sludge process.

Intake manifolds are not an issue on the 4.3L however, the OEM intake gasket failure rate is nearly 100%, especially if the cooling system is not maintained properly.

The entire cooling system must be flushed using a chemical cleaner to bring it back to satisfactory condition. This can be done at home in a couple of hours. Most auto parts stores have the cleaner in stock. A cooling system pressure test will determine if the intake gaskets need replacement. Felpro part #MS98002T gasket set, if installed properly, will not leak. Replacement time is approximately 4 hours. Plus another 45 minutes to replace the water pump and you should be good to go.

 

Even if you need to install a new radiator they are like $125. But flush your system first as Capt Hook says.

 

Thx. Found out yesterday that the heads need
to be repaired. Hopefully not replaced.
Engine got too hot.
$3000 repair for all. Now I need to decide
if its worth putting the money into.
Any thoughts on that?

 

Here's what it needs: radiator, water pump
New manifold & heads repaired or replaced.
Plus all the stuff that goes with it.
Registration and smog check were due
last month.

 

Honestly, if you cannot do what was suggested already, then it might be best for you to cut your losses and move on. I'm only saying this because of what you said in your original post (I'm referring to your injury) AND based on my OWN personal experience. This way you can spend some quality time looking for that early '90's 4.3L jem

 

You can buy used a engine cheaper than $3000. I would not put that kind of money in an engine that has got so hot it did that kind of damage. I'd buy a complete used engine. Most wrecking yards will know mileage on their engines. Find a low mileage one.

 

The saga is over ( hopefully) I put $3500 into
my Blazer. Shop I went to is owned by a family
member of some close friends. That right there
was a huge relief. Mechanic had my Blazer for
2 weeks. Ended up with new heads, Intake manifold
gaskets etc that go w/ all thts, new spark plugs,
radiator, water pump, of course new hoses too.
I think that's it. Oh a new coolant reservoir. Basically
A whole new cooling system. The mechanic
said the crack in my manifold didn't cause all of
this. He had same theory as the 1st mechanic,
Somewhere a few years ago someone mixed
coolants in my Blazer. I don't know who or when
because I never authorized this or saw anything
on an invoice.( I keep all my invoices etc.
& went through them to double check.
It's so strange. It's all behind me now.
My Blazer is running great & I'm so happy!
Thanks to all of you who posted. Your input
helped a great deal.
Now, to get my tailgate/ rear window to open,
Why they didn't put a key entry on this one
I'll never understand. But it has nothing to do
with the engine, transmission etc so it's not
urgent. Yay for that. Take care everyone!