General coolant supplement question...
Cadillac
 

Cadillac Forums | Help Us Help You | Advertise | Cadillac Parts | Cadillac News | Cadillac Classifieds / (Old System)

Cadillac Technical Archive | Cadillac Dealers | Cadillac Reviews | Cadillac Dealer Reviews | Cadillac Vendors

CadillacForums.com is the premier Cadillac Forum on the internet. Registered Users do not see the above ads.
+ Reply to Thread
Results 1 to 13 of 13
Community Lounge, Introductions and General Discussion Discussion, General coolant supplement question... in General Discussion; I have been asked a number of times about whether you should use coolant supplement pellets with DexCool in the ...
  1. #1
    kcnewell is offline Cadillac Owners Connoisseur
    Join Date
    Jan 2003
    Location
    Nevada, Still the land of the free!
    Posts
    2,236

    General coolant supplement question...

    I have been asked a number of times about whether you should use coolant supplement pellets with DexCool in the Northstar engine or 4.1/4.5/4.9 engine?


    Simple answer: USE THE COOLANT SUPPLEMENT PELLETS REGARDLESS OF
    WHICH TYPE OF COOLANT YOU ARE USING.
    The coolant supplement/sealer works to seal any microscopic porosity or incipient leak in the coolant system. Internal coolant intrusion is not good for any engine and the coolant supplement is cheap insurance against any internal coolant intrusion.

    The supplement should be added each time the coolant is changed. I think the confusion exists because factory installation of the coolant supplement was stopped in the late 90's as it was felt
    the supplement was no longer required and added cost and made the coolant system look "dirty". This happened about the same time the DexCool was introduced so people assumed the two happenings were related. This is not true. There is nothing in DexCool that negates the need for coolant supplement , especially in an older engine.
    Personally, I use the supplement in every car, snowmobile, tractor,etc. I own and I strongly recommend to everyone to use it as it is very cheap insurance.

    The standard green coolant and DexCool are both ethylene-glycol based products. The green coolant has a silicate based corrosion inhibitor and DexCool has an organic acid based corrosion
    inhibitor. The silicates in the green coolant get depleted over time and the corrosion protection diminishes dramatically. That is why it needs frequent replacement. The DexCool lasts virtually
    forever due to the different chemistry in the corrosion inhibitor. The ethylene-glycol is what give you the boiling and freeze protection. It never wears out but the corrosion inhibitors are equally important, especially in an aluminum engine. Corrosion protection in an aluminum engine is vitally important. Aluminum exhibits a phenomenon called hot transport deposition corrosion...microscopic bits of aluminum break away from the hottest areas (exhaust port) into the coolant and precipitate out in the cold areas of the cooling system (radiator). Cracks result
    in the hot areas as stress risers develop. Cracked heads, coolant leaks into exhaust ports and failed head gaskets are common signs of a poorly maintained cooling system where the corrosion
    inhibitors have failed. The cold rolled core of the head gasket will corrode from the edges where it contacts the coolant if the inhibitors have failed.

    Poorly maintained cooling systems on aluminum engines are common unfortunately because the coolant stays nice and green even after the silicates have depleted and corrosion sets in because the alum corrosion does not "color" the coolant. An iron engine will tell you the corrosion protection is gone because you see red rust in the coolant. Also, the alum engines deplete the corrosion inhibitors more quickly than an iron engine.

    DexCool is not designed for 18 wheelers or trucks. Big commercial diesel engines need nitrates in the coolant to prevent cavitation and erosion of the wet cylinder liners. I do not
    think any big diesel engine manufacturer recommends DexCool. Any trucker experimenting with DexCool could have saved himself the bother and engine damage by reading his owners manual.
    Conversely, because it does not work in a big diesel is no reason to not use it in a gasoline passenger car engine.

    If the engine was completely drained and flushed and switched to DexCool that is fine. Continue to use the DexCool but I would still recommend periodic drains and refills. Since the engine was
    "plated" internally with silicates from the green coolant the DexCool lifetime advantage is not as effective and it need periodic replacement as it becomes contaminated with silicates
    from inside the engine thus depleting its corrosion protection over time. In either case...USE THE COOLANT SUPPLEMENT.

    The green silicate coolant has two undesirable side effects that bear mentioning:
    One is that the silicates are very abrasive and shorten water pump seal life by abrading the surface of the seal. Also the silicates can build up on the seal surface and "unseat" the seal
    causing seepage. The seal is fine but the silicate contamination does cause a leak. The coolant supplement pellets tend to prevent the latter situation by cleaning the surface of the water pump
    seal and preventing the silicate build up. The little fibers in the supplement literally "scrub" the surface preventing the silicate buildup. It doesn't seem to prevent erosion of the seal
    by the abrasive silicates unfortunately. The second situation is more pronounced in occasional use cars that might also get a higher than the recommended 50/50 concentration of coolant (more coolant than water). The silicates can "congeal" in low flow areas like the heater core forming this
    green "jello" that plugs the heater core. The lower the flow, the greater the coolant concentration and the longer the down times the greater the tendency to form the green jello. Usually it can
    be flushed out with a strong water flow from a garden hose but it is a pain.
    Both of these problems prompted the use of DexCool from the factory as well as the long term corrosion protection compared to the green coolant.

    Switching the system over to DexCool will not necessarily give lifetime corrosion protection as previously explained but it will eliminate the two problems above which are worthwhile in themselves.
    Neither the green coolant nor DexCool should ever be added straight to the cooling system. ALWAYS PREMIX 50/50 COOLANT/DISTILLED WATER. Premixing is important because you do not want to run a greater than 50/50 mix of coolant. The cooling system will loose capacity due to the lower heat transfer capability of the coolant and lower flow due to the added
    viscosity of the coolant. The added silicates in the green coolant are not desirable as mentioned least the dreaded green jello form. The acid DexCool must be premixed as it is very
    undesirable to introduce the acidic coolant directly or have a greater than 50/50 concentration.
    My personal recommendation is to avoid flushing the system as it ends up introducing plain water and/or flush chemicals which are very harmful (minerals and caustic, respectively) Just drain the
    radiator periodically and refill with 50/50 premix. do this once a year and the system is protected as a fresh charge of corrosion inhibitors is always being introduced and the coolant is always
    being replenished. Since no Allantes ever came with DexCool it is safe to say that draining and refilling with either coolant would be recommended as DexCool in any Allante will be only partially
    effective over the long run due to the inherent silicate contamination.

    Several more things come to mind regarding the overall coolant issue. You will see at truck stops a "heavy duty" or "long life" silicated green coolant. NOT RECOMMENDED. Too much silicate
    concentration for a gasoline engine. Highly likely to gel and/or cause water pump seal problems. Just as DexCool is not designed for heavy duty diesel use the "heavy duty" silicated coolant is
    not designed for passenger cars.

    I recommend Texaco DexCool coolant. Texaco developed the stuff in conjunction with GM and is the OEM supplier. Others market a "DexCool compatible" long life coolant but I would recommend the Texaco product. I also recommend Prestone.

  2. Remove Advertisements
    CadillacForums.com
    Advertisements
     

  3. #2
    MMNineInchNails's Avatar
    MMNineInchNails is offline Cadillac Owners Enthusiast
    Join Date
    Jul 2003
    Location
    San Clemente, CA
    Age
    27
    Posts
    989

    Re: General coolant supplement question...

    Holy shit lets just write a book here

  4. #3
    kcnewell is offline Cadillac Owners Connoisseur
    Join Date
    Jan 2003
    Location
    Nevada, Still the land of the free!
    Posts
    2,236

    Re: General coolant supplement question...

    In spite of all the other nonsense that goes on here.....It's still primarily a Cadillac tech site. The precedeing post was another in an ongoing effort on my part to give good complete tech advice on subjects that I have the knowledge of.

  5. #4
    torqmonster's Avatar
    torqmonster is offline Cadillac Owners Member
    Join Date
    Oct 2003
    Location
    Germany
    Age
    44
    Posts
    12

    Re: General coolant supplement question...

    Very interesting information. Sounds like you are a chemitrist? I hears about the corrosion problem in the Northstar engines and was concerned as a stupid mechanic replaced the dexcool I put in with regular green coolant when the engine was out due to a tranny service. But as it is fresh, I think I can let it in until spring. Nineinchnails is probably one these guys who think gasoline is the only fluid which is worth spending money for... but you have a cool car, the 69/70 De Villes are among my favorites. Donīt let them die due to no service.

  6. #5
    MMNineInchNails's Avatar
    MMNineInchNails is offline Cadillac Owners Enthusiast
    Join Date
    Jul 2003
    Location
    San Clemente, CA
    Age
    27
    Posts
    989

    Re: General coolant supplement question...

    Quote Originally Posted by torqmonster
    Nineinchnails is probably one these guys who think gasoline is the only fluid which is worth spending money for... .
    um... No. It was a joke when I posted that reply. I understand that KC is an intellegent guy, but haven't seen a post that lengthy in quite some time. And also for your information, I do buy other fluids and put them in the car. That's stupid to post something like that when I've never even put a full tank of gas in the car. I've never even been to the gas station in it yet. I've had to replace a lot of things on it to get it going and I've done all the labor myself. Don't say stuff like that unless you really know what you're talking about because in this case, you obviously don't.

    Thank you KC for the info.

  7. #6
    kcnewell is offline Cadillac Owners Connoisseur
    Join Date
    Jan 2003
    Location
    Nevada, Still the land of the free!
    Posts
    2,236

    Re: General coolant supplement question...

    Just do us all a favor....Don't get into a flamewar over this. 'Cause then some bucket head with no sense of humor will close the thread! ( For the good of the board of course! )

  8. #7
    Stoneage_Caddy's Avatar
    Stoneage_Caddy is offline Cadillac Owners 10000+ Posts
    Automobile(s): Gobi 01 Frontier/Ishi 96 Nighthawk/Gladys 94 Deville I Loved
    Join Date
    May 2003
    Location
    Undisclosed location in FL
    Posts
    14,603

    Re: General coolant supplement question...

    any good ways to test the coolant , or should i just use my old school turkey baster/guage thing ? coolant looks dirty but like you mentioned that could be the sealant pellets , i added some pellets last weekend but im afrid to do the coolant as i dont know where to put it or how to contain it (before i got the dog i used to let it go down the storm drain)

  9. #8
    kcnewell is offline Cadillac Owners Connoisseur
    Join Date
    Jan 2003
    Location
    Nevada, Still the land of the free!
    Posts
    2,236

    Re: General coolant supplement question...

    Quote Originally Posted by Stoneage_Caddy
    (before i got the dog i used to let it go down the storm drain)

    I still do...

  10. #9
    ProfX's Avatar
    ProfX is offline Cadillac Owners Member
    Automobile(s): NONE
    Join Date
    Apr 2003
    Posts
    10

    Re: General coolant supplement question...

    Good stuff Newell...thanks for the info. D.

  11. #10
    DFBonnett is offline Cadillac Owners Fanatic
    Join Date
    Nov 2003
    Posts
    298

    Re: General coolant supplement question...

    kcnewell..
    Thanks for the education. Often we know what to do but not the why.

  12. #11
    Realtor1's Avatar
    Realtor1 is offline Cadillac Owners Fanatic
    Automobile(s): 1993 STS, 1997 STS, 2002 SLS, 2007 CTS 3.6
    Join Date
    Jul 2003
    Location
    Elizabethtown KY
    Age
    44
    Posts
    378

    Re: General coolant supplement question...

    Yes, thank you very much for the info....

  13. #12
    ikarukeion is offline Cadillac Owners Member
    Join Date
    Jan 2005
    Location
    Dearborn, MI
    Posts
    43

    Re: General coolant supplement question...

    OK, so what are coolant pellets and where do i get 'em?
    I know its and old thread but, how about a blast from the past?

  14. #13
    Jesda's Avatar
    Jesda is offline Super Moderator
    Automobile(s): An endless stream of Sevilles.
    Join Date
    Sep 2003
    Location
    St Louis MO
    Age
    32
    Posts
    22,240

    Re: General coolant supplement question...

    Thats a great post! You can find supplements at your GM dealer. Barsleak offers them too. I believe they make them for GM.

    http://www.barsproducts.com/

    Avoid the product with aluminum flakes. It forced me to get a new radiator.

Quick Reply Quick Reply

Register Now

Please enter the name by which you would like to log-in and be known on this site.
If you do not want to register, fill this field only and the name will be used as user name for your post.

Please enter a password for your user account. Note that passwords are case-sensitive.

Please enter a valid email address for yourself.

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Bookmarks

Cadillac Posting Rules

  • You may post new threads
  • You may post replies
  • You may not post attachments
  • You may not edit your posts
Read about Lincoln | Buick | Kia Forte Forum
Need products for your Cadillac? Check out your options at the links below:

custom floor mats | Cadillac Chrome and Black Chrome Wheels | window tinting