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Inherited Impala

Discussion in 'Non-Mopar Tech Support' started by Scrounge, Oct 23, 2015.

  1. Scrounge

    Scrounge Well-Known Member

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    Thanks for the update, Rick. I think there should be more than one coolant expert, but at the moment, you seem to be the go-to guy in this forum on that topic. The car has a coolant seep, and I've so far only added distilled water to it. When I buy coolant, it won't be Prestone.
     
  2. Rick Anderson

    Rick Anderson Well-Known Member

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    IAT, OAT and HOAT are Ethylene Glycol based, the Glycol does the "anti-freeze" property. They differ in the anti-corrosion package that is added to them. The Glycol doesn't wear, the anti-corrosion package wears out, that is why you need to change it, or corrosion starts.

    OAT anti-freeze also does NOT coat or fill in pock marks, like the old IAT and the newer HOAT anti-freeze. The water pump in most cooling systems will suffer cavitation that will cause pock marks. That is why manufacturers put a lot of development into the water pumps of new engines before recommending OAT anti-freeze, so the water pumps cavitate less and thus can get by without the protection that old IAT and HOAT anti-freeze provided to them. For that reason alone, you should NOT retro-fit a vehicle designed for IAT or HOAT to OAT type anti-freeze.

    OAT anti-freeze does NOT react with minerals in the water with which its mixed, many areas of the U.S. and Europe have extremely hard water, and if you just use water from the hose to fill you cooling system and mix with the anti-freeze, other anti-freezes can react with the minerals in that hard water and form solids.

    OAT anti-freeze does NOT protect bronze/brass and copper used in older systems, again don't use it in vehicles recommended IAT or HOAT, especially vintage vehicles (older than 20 years) that likely do have these metals in their cooling system.

    DexCool, GM's version of OAT, uses 2EHA, that can soften certain plastics and rubber seals and parts in cooling systems. For that reason alone you should never use GM DexCool in a vehicle, even a modern vehicle, that it was NOT originally recommended for, especially older vehicles that are very likely to have those kinds of plastics/rubber as well as the metals OAT does NOT protect.

    Only the fact that GM has reformulated DexCool enough to fix the nightmares, and that most cars have gotten rid of those plastics/rubber and metals that would be a problem, is the reason Prestone has NOT gotten caught selling DexCool as some sort of universal anti-freeze.

    There are many versions of OAT, they all should be able to mix together, except GM Dexcool. Although DexCool has been improved and doesn't create an immediate nightmare when mixed with others, its just NOT wise to do it, don't mix DexCool with any other anti-freeze.

    The old Original Green IAT anti-freeze, arguably is the best anti-freeze, experts agree no one has come up with a more effective corrosion protection as the silicates and phosphates used in the original green IAT anti-freeze. That is, until that anti-corrosion package wears out, in just 2years/36k miles, then those silicates and phosphates start to form solids and can make a mess of the cooling system, NOT to mention allow corrosion from the water to start. It doesn't mix well with Hard Water and reacts with the Minerals in the water especially after its worn out. Original Green IAT has been improved over the decades as well, so horror stories of 1950's aren't true today with the Green IAT.

    I believe all Original Green IAT is the same formula, so there is NOT a single problem mixing different brands together. It does NOT mix with OAT. It will mix just fine with HOAT, but that mixture will still need to be changed at the IAT's shorter interval.

    "Arguably", you could retrofit Original Green IAT to any vehicles (that means flushing so there is NOT trace of the original anti-freeze) and it would protect better than the newer anti-freeze. Provided you used pure water (Distilled/De-Ionized) water to mix with it and you changed it every 2yrs/36k miles. No one was doing that, and then blaming the manufacturer's for their lack of proper maintenance. So all the manufacturers started switching to longer life anti-freeze, arguably it doesn't protect as well, unless you consider that the owner won't do the proper maintenance, then in that case the longer life anti-freeze does a better job in the long run.

    HOAT anti-freeze is a Hybrid, that is what the "H" stands for. It uses the safer chemicals from OAT anti-freezes and still includes some "silicates" to do coating and filling in of pock marks, but NO phosphates. It is more tolerant of Hard Water, it mixes with Original Green IAT and is more tolerant of OAT's than other anti-freezes (Gee, you'd think Prestone would use this and market it as an universal anti-freeze).

    HOAT arguably won't coat as much as Original Green IAT, but the combination of silicates and safer OAT ingredients, does make it more effective with older cooling system and water pumps that can cavitate, then OAT anti-freezes.

    If you have an old car that originally recommended IAT, and you can't find the IAT or just want to switch to a long life anti-freeze, then HOAT is clearly your best choice. OAT will NOT protect some of the metals used in your old car's cooling system, while HOAT will coat them with silicates. OAT will NOT protect the older simpler water pumps that are more likely to cavitate, while HOAT's silicates will coat and protect some. It will mix fine with IAT, and be tolerant of OAT's, while OAT will NOT.
     
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  3. Rick Anderson

    Rick Anderson Well-Known Member

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    Years ago, looking for anti-freeze to do preventative maintenance on one of my Dodge's, all I could find was this "All Makes, All Models, Mixes with any Color Anti-Freeze" stuff. So I started to google it and about anti-freeze, what I found out was really shocking, and keep researching it. Since what was going on was so shocking, I still remember a lot of the details today.
     
  4. valiant67

    valiant67 Rich Corinthian Leather
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    Keep in mind the sensor has a battery in it. It's already 7-8 years old so it would not be uncommon to see them start to die off unless they were already replaced.
     
  5. Scrounge

    Scrounge Well-Known Member

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    Rick, since encountering one of your earlier posts on the topic, I've been reading the ingredients before buying coolant for my Dakota . In Michigan, I buy Metro 50/50 coolant at a dollar store for $5 per gallon. Its listed ingredients are Water, Ethylene Glycol, Diethylene Glycol, Sodium Benzoate, Corrosion Inhibitors, Defoamer, Dyes. In Texas, Big Lots ran a sale on Peak 50/50 coolant for $5 per gallon, so I bought 2 of them. They're down there and I'm up here, so I can't quote the ingredient list, but it looked safe enough for me to use.

    Valiant, thanks for mentioning the battery. This is my first vehicle with these sensors, and I didn't know how they were powered (or connected). I don't think any of them were replaced, at least recently; the tires have tread, but they're not new. When buying a new sensor, how can I tell what its battery's lifespan is (or should be)? On one of the forums I linked to earlier, someone complained about new replacements lasting only 6 months. Perhaps that vehicle's problem was elsewhere.
     
  6. AllanC

    AllanC Well-Known Member

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    If you still are loosing a small amount of coolant but cannot find the source, the attached link has 3 pictures that I took when replacing the 2 gaskets that seal the crossover coolant pipe on a 2007 Chevy Impala with the 3.5 liter V6 engine.

    https://www.dropbox.com/sh/lyh5o9m2z9pwhga/AAA54REgZwoCjuqxZyYtr3oka?dl=0

    The first picture shows the coolant ports for both heads on the passenger side of the engine compartment. Second photo is a close up of the front head (closest to radiator) where there was no leak. OEM sealing gasket has been removed. The third photo shows the rear head with the OEM gasket in place. On this engine the rear portal was the leak source.

    Hope this helps in some way.
     
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  7. Scrounge

    Scrounge Well-Known Member

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    Thanks, Allan. Good pictures enhance a good description. I won't be back in Texas until next month, but it helps to know what I'm looking for.
     
  8. Scrounge

    Scrounge Well-Known Member

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    I'm back in Texas, and while I'm repairing the Dakota, I'm driving the Impala. It developed another weird glitch; last night when I pulled it into the garage, a tapping noise came from behind the glove box. It's louder inside the passenger compartment than it is under the hood, so I'm guessing it's somewhere under the dashboard. It stays on for about a minute or two, and even after turning the car off. Occasionally, it will start when I open the driver's door, even before I start the car. I disconnected the battery once, and when I reconnected it, it started again. But it's intermittent; it didn't happen when I just went for a bite to eat, and when I drove from there to the library. Any ideas?
     
  9. NYBo

    Level III Supporter

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    We has an 06 at my previous job that would do this intermittently. I believe it only happened when the battery was low.
     
  10. AllanC

    AllanC Well-Known Member

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    Follow this link as it explains a problem with an electronic actuator on the heater / AC system. It is either the fresh air / recirculate actuator or a blend door actuator. Years ago these doors on the heater / AC plenum box that direct air flow to the windshield, panel vents or floor were vacuum operated. Now they are electronically controlled with electric motors and logic modules.

     
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  11. Scrounge

    Scrounge Well-Known Member

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    I replaced the battery just before driving it home from Michigan. When I drove the Dakota back there for a month, I disconnected the battery and added some gas stabilizer to the gas tank.

    Good video Allan, this may be the fix. The Dakota has priority now, though. The Impala hasn't made any tapping today, so far.
     
  12. Scrounge

    Scrounge Well-Known Member

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    I talked with a service manager at the local Bowtie dealer. He said that when the battery is disconnected, the system has to reset (or maybe recalibrate) itself, and after it does so, the tapping will end. That happened again this week. Guess I'll have to put up with it so long as I disconnect the battery when leaving home for weeks.
     

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