Well my Eldo Just rolled 39k miles and other than the oil it appears to be all original. (recently purchased car)
Nobody around here knows me so here is a little bio. Not to brag mind you.. just to give a little credibility to my accounts and advise. I am a OEM auotmotive engineer. And specifically back in the 90s I was a water pump/FEAD engineer. I sat right accross the isle from the N* water pump engineer and am fully aware of the design of our cooling systems. So.. after searching and reading much around here I decided to change the coolant. (the car is 5 years old and it was a 1/2 gallon low on coolant btw)
Fist off, This is'nt a hard job at all. As long as you can raise the car, lay on your back, and don't mind gettig a little dirty? It's really easy.
Secondly something I saw people talk about was "pellets". Well, right on the cowl of my 01 Eldo there is a sticker that says to add 3 pellets when changing the coolant. Even gives the GM part number. (That sticker is on the plastic cover right above the radiator) Owners manual says 12.5 quarts of coolant.. and that's just about what drained out.
The pellets were very hard to find on a sat afternoon in my medium sized town! Turns out my local car quest had some bars-leak version of the pellets. I also don't waste my money on the "premixed 50/50" stuff. I always mix my own and measure it's density with a guage. But to each thier own.
I saw differening comments about the pellets and where to put them. But me being the eternal gear head... I know a little trick that simple and no hose removal is needed. Noted below.
1) Parking brake, jack drivers side of car, and support with a stand.
2) Remove the degass bottles cap. (pass side - mid fender)
3) Under car, Remove the plastic shield just rearward of radiator. (three 10mm screws)
4) Take a 4" bolt and cut/grind a slit into the threaded end of the shank. This will be a tool you can easily turn the pet-kok (mispelled on purp) with. This area is very tight if your trying to turn it by hand. I could'nt and just made a simple tool instead. You could easily do this with a 4-5" piece of dowl as well.
5) There is a little hole w/drain right benieth the pet-kok. Place a 3+ gallon bucket under there and open pet-kok. Takes about 20 minutes for it to fully drain this way but it works. ** now I lowered the car to get every last drop I could **
6) Retighten pet-kok, remove bucket, and lower car.
7) Using a 20+ oz glass that you can easily see in. Crush three tablets as much as possible. Add a 50/50 mix of coolant and stir.
8) Pour this mix into a pre mixed gallon of 50/50 coolant and distilled water.
9) Shake and turn upside down to keep the particals suspended in the fluid.
10) Fill degass bottle with your "home brewed" gallon and part of the 2nd premixed 50/50 gallon you have ready.
11) Start engine and turn heater on high. Fill as needed. After the motor is nice and hot free rev the motor with sudden bursts from idle to about 3000 rpms. This will aid in burping the system and generally you'll see that the coolant level is lower.
12) Once you have 2 gallons in, take the car for a drive. Try to go WOT 2-3 times from 10mph to just after the 1-2 shift.
13) Next morning check and top off the coolant level and just keep an eye on it from there on out.
The radiator on modern cars don't have a cap anymore. (most of them anyway)
The reason is because of airation in the coolant as it flows through the motor. These tiny air bubbles cause less than perfect cooling because the coolant is'nt 100% *liquid* coolant.
The solution became to ad a degass bottle in the system to give the air bubbles a place to migrate too. That way the coolant being introduce to the motor is mostly coolant. Vs the old school coolant and air mix.
If only you had clear radiator hoses you see exactly what I mean. In the dyno rooms during developement we use them just for that reason.
Besides... I'm a stickler for calling things by thier proper name. Even though I could'nt spell them properly to save my life.
Hey Rich, nice tip.... I just did this yesterday, it was pretty much exactly as you said on a 1997 ETC as well.....
The tricky part is opening the petcock.... my hands are just the wrong size for that.
Not knowing the dimensions necessary, I elected to make a high-tech petcock turning tool from a hardwood dowel. I happened to have a dowel right there, and I surmised I could keep cutting it easily until I came up with the right size.
Here are the exact dimensions I ended up with:
7/8ths inch diameter dowel.
5 & 1/16th inches long
With a scroll saw, I cut a notch in one end of it, which is 1/8th of an inch wide, and 5/16ths deep. A decent carbide-tipped table saw blade is also an eighth, so you could try just running the dowel thru that, too...
Now, knowing the dimensions, I might suggest buying a bolt, and cutting the slot in the end with a dremel tool cutoff wheel, or a bandsaw, or something along that line.....
The tricky part is opening the petcock.... it turns half a turn, and nothing much happens, but on the next half-turn to a turn, radiator fluid starts coming straight down out of that little opening on the bottom.... I have no idea how you'd turn it without being right under it, so, you're going to get radiator fluid pissed on you when you open it.... just get outta there, and get your pan under there as quick as you can. Also, I had to use pliers to turn the dowel, the wood was too smooth & slippery for my fingers... again, the right size bolt would be easier to grip, I think.....
The stream is small. This takes awhile to drain. Go check your email, or get a cigar & a beverage & get comfortable.
Otherwise, I followed the procedure above exactly, and it worked out fine.
My only doubt is that I only got about 6 quarts out doing it this way.... Maybe I'll just do it again next weekend. That should pretty much refresh the system, I would think....
Rich:
I got a 98 deville with about 61k on it and im getting ready to replace the coolant myself. just a couple of questions...(this is my first time attempting this on this car) Can you get these pellets anywhere else or is it only available at the dealership? next question did you use dexcool and is this something you would have to get at the dealership or at any autoparts store?..reason i ask is i've seem many brands with dexcool formula and just wanted to know if there is a particular brand that is reccomended. and last question.....in your post you said it takes 12.5 quarts of coolant but in your instruction you put in 20 oz with 3 tabs and then 2 gallons of 50/50mix. did you eventually add to that as you had the engine running? I just dont want to screw this up cause this car is new to me and i want to take care of it right.......thanks.....
Get the "cooling system suppliment" at any GM dealer or Barsleaks sealant tabs (HDC), or 2 tubes of the powdered version (G12BP) at WalMart, Kmart, Napa, AZ etc. Barsleaks is the same product and makes the tabs for GM.
The Jugs of coolant I got were Prestone Brand, from Wal-Mart, but in the upper portion of the label, there is the GM symbol, and it says "GM Approved DEX-COOL"... And it was orange-ish pink in color... as you would expect. I think it was about $10 a gallon.
I used the Bars Leak tube of powder, which they also have there, for around $1.50 each....
1) Parking brake, jack drivers side of car, and support with a stand.
2) Remove the degass bottles cap. (pass side - mid fender)
3) Under car, Remove the plastic shield just rearward of radiator. (three 10mm screws)
4) Take a 4" bolt and cut/grind a slit into the threaded end of the shank. This will be a tool you can easily turn the pet-kok (mispelled on purp) with. This area is very tight if your trying to turn it by hand. I could'nt and just made a simple tool instead. You could easily do this with a 4-5" piece of dowl as well.
5) There is a little hole w/drain right benieth the pet-kok.
Ok, I'm three steps into this..
Drivers side jacked up and jack-stand'ed (???
Expansion tank cap off
Plastic shield with 3 10MM bolts removed
Now, I'm looking for the petcock. I'm assumming it's on the drivers side of the rad, but there's so much darn plumbing and sheet metal/plastic in the way, I can't see anything.
I see what appears to be the drain hole in a piece of stamped metal, and I guess the petcock is directly above that?
But how does one get to it? From below? From the side??? Have attached image...
Any helpful hints?
TIA
Jim
EDIT:
OK, found it. You need to go up through that other hole - my pinky was the only finger small enough to fit through and not leave me wondering, "jeeze, what if my finger gets stuck in here... "...finally felt around and identified the bugger. Now I'm fabbing the pet-cock turning tool as described in prior posts...
EDIT #2
Ok, made the tool from piece of an old broomstick , got it on the petcock, and all is well in God's Heaven..almost finished draining now. The odd thing is the petcock is in the VERTICAL position when CLOSED - logic might dictate that it would be horizontal like household plumbing valves, but no...it was fairly easy to get turned, and I had my drain pan right there, so I only got about three drops of Dexcool on me...and the fluid looks like it was put in yesterday..perfectly clear orange...so I may not have had to do the change at all... she's creeping up on 5 years old, and the service history Kerbeck gave me when I bought her last year didn't mention any coolant change..but I'm betting that when I took it back to Kerbeck the day after I bought it with a slight leak at the water pump, they must have drained and refilled...oh well, better safe than sorry, and it's not that big a deal...peace of mind...
EDIT #3
Done. Took just under two gallons of what looks like brand new Dexcool out of it...clear as orange kool aid..but am I right in thnking that the color doesn't necessarily indicate the corrosion-resistant capacity of the stuff..so, like I said, peace of mind..
Now, I bought three gallons of Dexcool..Mixed 50-50, I got plenty for the next change, in 2016 or 168,000 miles which ever comes first...lol
Have attached pic of Draining Dexcool, and the petcock-turning tool (JH Part #PTT-001 rev. 2)
