coolant questions
proceeded to check the coolant.. and it was green.. DEX-COOL is not a green coolant, its orange-ish. So I suspect that the previous owner added regular coolant/antifreeze to the car, and this is why my car is running a tad warm.
I am going to do a coolant flush...most likely at a mechanic shop (I will take my own coolant with me)
Just wanted to be sure.. I purchased Prestone DEX-COOL (GM approved) antifreeze/coolant.. it comes in a silver 1 gal bottle.. this is the correct one, right?
Also, is it 2.75 gallons of DEX-COOL and 3 gallons of distilled water as the 50/50 mixture? (I know we can do a 30%water/70% coolant mixture if we want- any advantages to this?)
Oh and today the "low coolant" randomly came up on my DIC when i started the car in the morning. I shut her off, opened the hood, checked the coolant level, and it was fine. It was where it says "full here cold" or whatever. So why would that warning come on?
Lastly, should the mechanic use a coolant flush additive (like Prestone Super Flush) or use the garden hose method?
thanks for the help, and sorry for the long questions..
unless you live close to the artic circle the ratio of 2.75/3.0 is close enough. going richer (30/70) with antifreeze will gain you nothing.
using a flush will help if there is any type of oily residue in the cooling system
If you are going back to the long life dex cool you do need to flush out real well, and then flush with water a few times, if there is any of the green stuff left in there it will cause the long life stuff to not last as long.
Adding more coolant than water has no advantage unless you live in a climate where the temps usually get below -36. In fact a heavier concentration of coolant will make the car run hotter. A better blend for most places in this country is 60% water, and 40% coolant. Water is a better heat transfer than coolant. It can also help a lot to use a product like "Water Wetter", it makes the coolant work better at cooling and helps lubricate the parts.
Good Luck
My plans is to drain the reservoir, remove and clean the sensor, and hope for the best. Good luck!
i live in Cali.. so the winters usually never see anything lower than 50*F at the lowest.. and summers can get up to 120*F depending on location. Average temps throughout the year are about 70*F, and summer average is right around 100*F.
I just want to drain it and refill it with dexcool, not because it is longer lasting, but because that is what is recommended/needed
as far as the low coolant temp on my DIC.. i checked my garage, no leaks. resevoir tank is perfect too. where is the sensor? make i can clean it too.
thanks





The Best of Corvette for Corvette Enthusiasts
The manual recommends NOT using chemical flush FWIW.
Good Luck
+++++++++++++++++++++++++++++++++
Flush Procedure
Important
Do not use a chemical flush.
Block the drive wheels.
Place the transmission in Park or Neutral.
Engage the parking brake.
Run the engine until the thermostat opens.
Stop the engine.
Follow the drain and fill procedure using only clean drinkable water repeat if necessary until the fluid is nearly colorless. Refer to the drain and fill procedure.
Fill the cooling system. Refer to the drain and fill procedure.
+++++++++++++++++++++++++++++++++++++++
Draining and Filling Cooling System
Caution
With a pressurized cooling system, the coolant temperature in the radiator can be considerably higher than the boiling point of the solution at atmospheric pressure. Removal of the surge tank cap, while the cooling system is hot and under high pressure, causes the solution to boil instantaneously with explosive force. This will cause the solution to spew out over the engine, the fenders, and the person removing the cap. Serious bodily injury may result.
NOTICE
When adding coolant, it is important that you use GM Goodwrench DEX-COOL® or HAVOLINE® DEX-COOL® coolant. If Coolant other than DEX-COOL® or HAVOLINE® DEX-COOL® is added to the system the engine coolant will require change sooner; at 50 000 km (30,000 mi) or 24 months.
Notice
DO NOT use cooling system seal tabs, or similar compounds, unless otherwise instructed. The use of cooling system seal tabs, or similar compounds, may restrict coolant flow through the passages of the cooling system or the engine components. Restricted coolant flow may cause engine overheating and/or damage to the cooling system or the engine components/assembly.
Drain and Fill Procedure
Important
If the procedure below is not followed a low or high coolant level condition and/or vehicle damage could result.
Park the vehicle on a level surface.
Follow the steps below to remove the radiator surge tank fill cap:
Slowly rotate the cap counterclockwise1/4 turn and then stop. Do not press down..
Allow any residual pressure, indicated by a hissing sound, to be relieved.
After all hissing stops, continue turning counterclockwise to remove the cap.
To tighten the cap, use hand tight pressure only.
Open the radiator drain ****.
Allow the system to drain completely.
Inspect the engine coolant:
Discolored -- follow the flush procedure below.
Normal in appearance -- Continue with the next step.
Close the radiator drain ****.
Important
When filling the cooling system use a 50 to 60 percent concentration with DEX-COOL® coolant.
Fill the system through the surge tank opening.
Fill half the capacity of the system with 100 percent DEX-COOL® coolant.
Slowly add clean drinkable water to the system until the level reaches to the base of the neck.
Start the engine.
Idle engine for 1 minute.
Install surge tank cap.
Cycle the RPM, idle to 3000 in 30 second intervals until engine coolant reaches 99°C (210°F).
Shut off the engine.
Refer to step 3 above to remove the surge tank cap.
Start the engine.
Idle engine for 1 minute and fill surge tank to 1/2 inch above COLD FULL mark on the radiator surge tank.
Install the surge tank cap.
Cycle the RPM, idle to 3000 in 30 second intervals until engine coolant reaches 99°C (210°F).
Shut off the engine.
Top off coolant as necessary, 1/2 inch above FULL COLD mark on the radiator surge tank.
Rinse away any excess coolant from the engine and the compartment.
Inspect the concentration of the coolant.
i will print it out and give it to the mechanic. looks pretty simple, i can probably do it myself if i really want...
by the way, is there a difference between GM Goodwrench DEX-COOL and Prestone DEX-COOL that i bought?
I understand the formula of DEX COOL has changed from the early days. GM is still using it today. the local lube place needs to keep current on coolant. it's common "what I sell is better than what you want"
DEX COOL is DEX COOL regardless of the color of the jug.














