Hi everyone,

I've got a 1999 Blazer 4WD V6 4.3L, with 152,000 miles. Radiator is split, so in order to get back and forth to work, I'm adding/checking coolant before and after driving. I know, I know, but I don't have many good options right now - fortunately I live close to my work, and the temp hasn't spiked yet - still in the normal range. I've done plenty of work on other vehicles, but not anything with the cooling system on the Blazer up to now.

I've also read about half way through the whole "DEX-Cool war" err...debate thread, and I've made the decision to move to Prestone. Back in early and mid 2007, between 90 & 100k, I had the intake manifold gaskets replaced, as well as the fan cluch and water pump. I had multiple coolant flushes, and the techs all reported that they got tons of gunk out of the system when they did. In the words of Homer Simpson, DOH! That should have been my first clue...hindsight and all that. Unfortunately they put DEX-Cool back in. Anyway, I'm not here to fire up another debate. I've already made my informed decision (99% sure, anyway), and am looking to do the work myself this coming weekend.

Here are my questions. If I'm replacing my radiator, I know I probably need to replace the hoses, but what about the heater core? Should I go ahead and get that while I'm at it? Also, should I replace the pump again? I know the thermostat and radiator cap (I've read a specific Stant model).

What else? Any specific tools that I'll need that I should have/rent? Thinking about using the Prestone Flush 'N' Fill Kit. Anyone with experience using this or anything else better? http://www.prestone.com/products/acc...p#accessories2

Finally, what brand of radiator (and heater core, water pump, etc) is reccomended? I've been looking at the AutoZone site, and Spectra is one of the options with a Limited lifetime Warranty (haven't read what the "Limit" is, but I'm assuming ownership, and proof of maintenance).

I read this on the site www.imcool.com:

The vehicles. From their examinations, GM isolated these vehicle models as suffering from cooling system contamination: ST Utilities and Pickups with the 4.3-liter engine, W cars with the 3.1 or 3.4 liter engines and the 2000 Buick La Sabre/Pontiac Bonneville. Below are the procedures to be used for each series.

ST Utilities and Pickups. A small number of ST utilities like Chevy Blazer, GMC Envoy, Olds Bravada, and ST pickups with 4.3-liter V6 engines were found with iron oxide contamination. This problem requires a cooling system chemical flush. For instructions, get a copy of GM Bulletin 99-06-02-012B and follow them carefully!

Since heat is a catalyst, while flushing with the recommended chemical cleaner, be sure to allow the engine to achieve a normal operating temperature. Use a scan tool to accurately measure the coolant temperature. And since the cleaner must be able to flow past the contamination, check to be sure that not more than the two top rows of the radiator’s tubes are plugged. If the coolant will not flow through the third row down from the top, flushing will do no good; the core must be replaced.

The Stant 10230 Radiator Cap. Replacing the existing radiator cap on the ST trucks, U vans and “W” cars with a Stant 10230 or 11230 is advised. This spring-center valve design provides extra system sealing protection over that of the drop-center model; it is less vulnerable to contaminants interfering with the seal.

GM suggests that coolant bottles should be filled to the “full” mark when cold. The vehicle owner should be counseled to keep the bottle properly filled with 50/50 mix. These suggestions would appear to be wise for a number of vehicle applications.




What else should I be on the lookout for on this vehicle?

Thanks in advance...

Jonathan
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Ok, so I FINALLY got through the ENTIRE "WHO'S HAD GOOD LUCK WITH DEX-COOL" thread. In case you haven't seen it, READ IT. It is worth the read, regardless of whether you are a Dex-Cool fan or not.

Afteer reading the thread, I've decided to replace the heater core, water pump, thermostat, cap, and hoses as well as switch from orange Dex-Cool to most likely Prestone (or just about anything other than orange, which resembles rust even when new). This pretty much leaves the overflow tank, temp sensor, and the block (did I miss something?)

So, my question is this. I'm concerned that doing the flush after replacing the radiator, heater core, and water pump will just junk up those brand new items.

Am I overly concerned, or is there something I should do to minimize the contamination of the new parts? As it is a 4WD, I may not be able to get to the block drain plugs, and I'm not sure I want to mess with them anyway. After all, it is a 99, and to my knowledge the drain plugs have never been removed.

Thanks for any advice, input.

Jonathan aka Jonboy

 

you can use distilled water with water wetter for the summers. and or use peak green original formala in the blue can for 95 older vehicles

 

If you got it flushed out properly before you replace the components, you shouldn't have to worry about it afterwords.

 

I agree. Flush it first and be sure to flush through the block drain plugs if at all possible to get the crud that is in the bottom of the block.

Water wetter should serve no purpose in your application. (I'm not convinced is is much if any help in lowering temps. when you have an overheating concern.)

 

Thanks for the replies guys. After a little more reading, there's no way I'll be replacing the heater core, at least not right now. I know I could do, it, but I simply don't have the time. I just hope it holds out, because 1, I don't have the 10+ hours required to do it (based on what I've seen from a couple of other peoples' experience, and 2, I don;t have the money to pay someone else to do it. I'll bypass it if I have to.

Kyle - apologies for the double post. I plead newbie ignorance for not reading (and consequently not following) the forum rules, and it won't happen again, as I've read them now. Feel free to delete my post in the other thread if you like. I won't be offended.

Cheers!

Jonboy

 

For what it is worth to anyone who may stumble upon this thread.... I went through a couple of different rental tools that were supposed to do the job. I checked with Carquest, Auto Zone, Advance, and O'Reilly. NONE of them had the correct tool for rental or in stock for sale. I tried and tried to get that fan clutch nut undone, but I simply didn't have the right tool. I even tried making a tool, but I didn't have the right raw materials required, and the largest crescent wrench I had was a 12in, which isn't large enough. Late Saturday evening, I finally gave up. Sunday afternoon, I decided to call NAPA - they actually had the tool in stock. Unfortunately it was $79. I forked over the money, because I had to get the vehicle driveable again by Sunday night. Once I had the tool in hand and applied to the fan nut, I had it undone in literally seconds. The tool I used was a NAPA 3472. It worked like a champ.

I was able to get the rest of the job done, replacing every piece of the cooling system except the heater core, and I was driving by 10pm that evening.