Some help with L200 cooling system repair?

[MikeNW]

2002 L200
170K miles
hoses are original So I will replace them and the T-stat this week.

Couple of questions...

Wally World has Prestone "works with all cars" anti-freeze and "dex-cool compatible" anti-freeze, which one should I use?

After I drain old coolant, install new hoses, should I flush once with water and (I thought I read) dishwashing soap to clean out the system?

The owner's manual sez the system holds 7.4 quarts, I am assuming that a gallon of coolant and the rest water should be OK?

Thanks

[MikeNW]

One more- should I replace the ECTS too?

[fdryer]

An '02 L-series car uses the brass coolant sensor but you can remove it to check - it should be brass encasing the thermister electronic element. All L-series went with brass sensors as well as every model after the S-series fiasco using the plastic ones.

Flushing a system can be as easy as using plain water for a clean system to using chemical or dishwashing detergent to clean out dirty systems. Use what you feel. Just be sure to flush this cleaning solution with more fresh water in preparation for new coolant. Leave the old hoses and t-stat in until after flushing then replace them.

Use any coolant you choose with the best price but keep in mind that some coolant may not have a 5yr/100k mile life so research. Flushing the cooling system is always the best thing to do in preparation for new coolant and/or changing from one type to another. The mixing of coolant just reduces the longevity of the better coolant against the lesser of the two so mixing isn't bad as much as losing the capability of longer life coolant being reduced when mixed with another type with less life. With less than two gallons used in cooling systems, it should be hard to buy one gallon of 100% anti-freeze with the remaining distilled water for most Saturns.

[MikeNW]

WRAP-UP comments:
Beware- Changing hoses and T-stat was a difficult chore on this car (2002 L200).
The lower hose clamps are nearly inaccessible. The hose is buried and I had to remove the battery, battery tray, and move the main UHJB to get it out. A frustrating, poor design.

The Rock Auto hoses (Dayco) were too long, one would figure they would just install as-is but I had to cut both upper and lower hose to fit properly.

The Chilton's book was useless. The main cooling section didn't even show you the drain cock on the radiator. It described a drain bolt ON THE WATER PUMP. I accidentally found the location of the drain cock, in another section.

Final Question.

I drained and refilled several times with water. Finally the water drained clear. Then I put 1 gallon of Prestone Dex-Cool compatible coolant into the expansion tank, which filled it. Even after running the car a few miles, it was still full.

Will the fluid in the expansion tank eventually mix into the system? There is a hose exiting the tank, leading to the lower rad. hose. How does fluid get into the tank? Through the top smaller hose? Does fluid normally circulate through the tank?

Thank you.

[fdryer]

Originally Posted by MikeNW

....... Will the fluid in the expansion tank eventually mix into the system? There is a hose exiting the tank, leading to the lower rad. hose. How does fluid get into the tank? Through the top smaller hose? Does fluid normally circulate through the tank? ....

Yes, coolant will mix with water automatically. the coolant container is part of the cooling system; its the reason it has the pressurized cap since this is the only place to monitor and top off coolant after a flush/fill procedure. Once filled it will hardly need topping off.

From the service manual;

The Saturn cooling system uses a pressurized coolant surge tank and does not have a reservoir or overflow bottle. All components of the cooling system are filled from the surge tank and no additional bleeding is necessary.

At cold start-up, the thermostat will be in the closed position. The engine water pump will pump coolant through the cylinder block and head. Coolant is also pumped through the heater inlet hose to the heater core. Coolant returns from the heater core through the heater outlet hose to the engine block. Any air in the engine block or heater core is carried by coolant to the surge tank through the head degas hose. Coolant then flows from the surge tank back to the engine block through the return hose portion of the lower radiator hose.

When the coolant returns to the engine block, it flows over the thermostat element. When the coolant temperature reaches 90°C (194°F), the thermostat will begin to open. The coolant will flow through the upper radiator hose, through the radiator, and back to the engine through the lower radiator hose.

[MikeNW]

Excellent. Thanks again