Coolant Change for 2002 Saturn, best practices

College daughter has 2002 saturn, I have gotten lazy and had mine done at a shop, but asking the best practice to do a coolant change as we will do it together. SL2, how many cylinders, I am not sure.

I plan on Peak global, assuming dexcool is currently in the system.

The cheapest way to remove the Dexcool coolant and introduce a universal coolant in both vehicles is with a coolant exchange machine.

Call around to some shops, and ask if they’ll give you a package deal.

I would.


I suggest sticking with the Dexcool

It is fine if you change it on time every 5 years

That is my opinion

I believe the 2002 SL2 all came with 4-cyl engines.

Best practice to change coolant is to drain the current fluid, refill with fresh water, run the engine until it is warmed up and the upper radiator hose is hot. Let the engine cool, and drain the radiator again, and repeat until the drain water is clear. Change out the thermostat and the radiator cap, and any hoses that look or feel suspect, then refill with the proper coolant mixed for your regional winter climate. Burp or bleed tbe system, and then get a cold one and relax.

Totally disagree with BustedKnuckles (no offense, I usually agree with you most of the time, just not this time).

There is a drain on the block and one on the radiator, open both and completely drain the system. Do not flush at all, no fresh water flush either. Simply drain the old stuff out.

There is a reasonably good chance that the radiator drain plug will not seal properly when you put it back in. BTW, you can use a 1/4" drive extension in the center of the old plug to get it to turn to remove. A replacement plug is available at O’Rielly’s but not at AutoZone for some reason. Its pretty generic to a lot of GM vehicles.

I think I used Peak in mine the first time I changed it, but I used Prestone this time because it was on sale. It makes no difference as long as you use the long life universal coolant. Any long life universal coolant will meet GM specs for no silicates.

If you use the premix, OK. But if you buy the full strength, be sure to use purified or distilled water to mix. I use a 2:1 ratio antifreeze to water instead of 50:50.

The system is self bleeding so you do not have to worry about that. I would not worry about the thermostat because the Saturn monitors the coolant temp rise pretty close and will set the MIL if there is the slightest problem with the thermostat. Mine was set when the coolant temp only hit 179 in the prescribed time instead of 180.

If the cap is bad, the engine coolant temp will rise every time the car pulls a hill, so if it isn’t doing that, I wouldn’t worry about it. Having said that, I replaced mine on my 02 Saturn this summer for that reason, but it turned out not to be the cap, it was pulling a long grade in 106F weather and the gauge only went to the half way mark. It did it again after replacing the cap but that was pulling that long grade out of Death Valley to 395 in CA when it was 121F, again only going up to the halfway mark. Normally the needle stays at two needle widths above the quarter mark like its painted on.

This is an all aluminum engine so it is sensitive to any minerals in the water used in the system, that is why I really don’t like to see anyone flush it out with a garden hose. A little residual old coolant will not hurt the system as bad a minerals from water will. Any if you get any mineral water into the system, you will never get it all out.

BTW, the block drain is under the thermostat housing where the lower radiator hose is attached and re-torque the bolt to 26 ft lbs. or good and snug.

Thanks for the info, great stuff!

One more thing, it hold 7 qts of coolant so one gallon of full strength and the remainder fill with distilled or buy two gallons of premix and have a qt left over.

I have not been using the radiator drain plug for the last 20 years. I had one brake on me on a car and had to take it to a radiator shop to have it fixed (R&R myself), so it was a lot of headache. I just pull to lower radiator hose nowadays. Is that just me?

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Sometimes radiators don’t have drain plugs, so that’s the only option. The drain plug is really just a convenience, and isn’t actually necessary. You do have to exercise some caution and patience though in removing the lower drain hose, as it often sticks after years of being in one place, and in getting it loose you could crack the radiator outlet fitting. Retail auto parts stores in these parts often sell radiators which don’t have drain plugs.

It’s interesting – the comment above – about the importance of not putting pure water into the system, even for an hour or two. In the past I’ve always flushed the radiator in my 90’s Corolla and 70’s Ford truck using plain tap water from a garden hose and never had difficulty. I’d drain the radiator (not the block) then connect everything except I’d remove the top hose to the radiator. Then I’d idle the engine and add enough through the garden hose to replace water coming from the top hose, to keep the radiator full. I thought the only risk of this practice was possibly cracking the block or head by putting in cold water with the engine running. But the cold water is added at a pretty slow rate because the thermostat never totally opens with cold water entering all the time, so adding tap water maybe one quart per 3 minutes at the most, and it would mix with the hot water already circulating in the engine I guess.

Later, to avoid the risk of cracking the block, I switched my coolant exchange method to just draining the radiator and refilling with cold tap water, running the car 15 minutes, letting it cool off for an hour, then repeating that a couple times.

I’ve always refilled the final time with a 50/50 mix of plain tap water and Prestone, but from comments here the most recent time I did this, I used distilled water instead. I guess going forward I’ll have to not use plain water at all, only a 50/50 mix even during the clean-out phase. Some add’l expense, but not that much if it makes for a more robust cooling system.

If you don’t pull the radiator plug, then you are leaving quite a bit of coolant in the radiator. Its a horizontal flow radiator and the hose is not at the bottom of the side tank. Besides, if you put it up on ramps, you can hang about a foot of 1/2" hose (or maybe its 3/8" hose) from the bottom of the drain port into an old antifreeze bottle or other 1 gallon container and it keeps from making a mess. Can’t make a suggestion for the block drain though, it just gets messy.