Los Del Rios, Deep Blue Something, Ace of Base and the Dodge Stratus -- name four things that were really popular for two years in the mid-1990s, and then fell off the map. Like the aforementioned musicians, the Stratus had the perfect formula for success in its time, and indeed captivated audiences for a couple golden years. But that formula proved fairly narrow and easily imitated, leaving the Stratus consigned to the one-hit-wonder category of automotive history. If you and your Stratus end up sitting at the crossroads counting blue cars after overheating, a simple radiator change might be all it takes to regain your Coolio.
Park your Stratus on level ground and allow it to cool down completely. Lift the front end with a floor jack and secure it on jack stands. Connect a battery saver device to the car per the manufacturer's instructions in order to retain your radio, seat and computer settings after you disconnect the battery, and to prevent the cooling fan from turning on unexpectedly. Disconnect the negative battery cable and lay it to the side.
Remove the black, plastic air resonator chamber from the top of the engine, using a ratchet and socket. It's held on with a few easily accessible bolts from the top. Locate the lower radiator hose, and use a screwdriver, small socket or pliers -- depending on your hose clamps -- to loosen its clamp at the radiator. Place a drain pan under it, and very carefully wiggle the hose off the radiator. Normally, you'd use the petcock valve to drain the radiator; but this is faster and easier, and you have to remove the hose anyway.
Remove the upper radiator support and the body cladding that covers it. Use a small, flat-head screwdriver to pop up the plastic retainers on the fascia piece over the radiator. Next, remove the six bolts that hold the grille, fascia piece and upper radiator support to the car's body. Use a box-end wrench to remove the two nuts holding the hood latch to the upper support. Pull the grille and upper support off the car to reveal the radiator.
Remove the four bolts that hold the electric cooling fan to the radiator, pull the AC line out of the mounting tab on the fan, pull the radiator fan up far enough to access the electrical plug and unplug it. You may find the metal mounting tabs stuck to the fan mounts; pull them off and transfer them to the fan mounts on the new radiator. Disconnect the upper radiator hose and pull it off the radiator.
Remove the bolts that hold the transaxle cooler lines and AC lines to the radiator, and lift the brackets out. The AC bracket bolts are accessible through the lower holes in the front bumper. Loosen the clamps for the transmission cooler lines and pull the lines off the radiator. You may want to wrap a rag around them as you pull them off to soak up any spilled fluid, and mark the lower hose with a piece of tape. Double-check that you've disconnected everything, and carefully wiggle the radiator up and out of the car, being careful not to damage the AC condenser.
Twist the rubber mounts from the mounting studs on the bottom of the old radiator if they came out with it, and push them back down into their receptacles in the chassis. Installation is the reverse of removal. Start by carefully pushing the new radiator down into the mounts. Put the AC line mounting brackets on the new radiator, and tighten them down to 45 inch-pounds with a torque wrench. Do not overtighten, or you'll damage the plastic mounting boss on the new radiator.
Reconnect the transmission cooler lines, placing the marked line on the bottom. Tighten the hose clamps to 22 inch-pounds, or just snug. Reconnect the upper and lower radiator hoses. Plug the cooling fan in, lower the fan to the radiator, and reinstall its mounting bolts. Lower the upper radiator support over the radiator, along with the grille. Take your time here -- the upper mounting studs may be difficult to line up with the mount holes in the support. Install the hood latch and all of the bolts just so that they're tight. Install the plastic push pins.
Open the coolant cap on top of the engine, refill the cooling system with as much 50/50 ethylene glycol and pure water coolant mix as it will take, then check underneath for leaks. Once you're satisfied that everything is sealed, reinstall the intake resonator and lower the car, leaving the coolant cap off. Reconnect the negative battery cable and disconnect the memory saver. Start the engine. Briefly briefly rev it up to about 2,500 rpm. Check your transmission fluid level with the dipstick, and add as necessary to bring it up to to the appropriate level; it may take a quart or more.
Repeatedly raise engine rpm to about 2,500, hold it there for 10 seconds, and allow the car to idle for 10 seconds. After every other cycle, check the coolant level in the coolant cap, and keep adding until the engine will take no more coolant. The coolant cap is the high point in this system, so there's little need for additional air bleeding after the system is full. Once it is, install and close the cap, and fill the coolant overflow bottle up to the "MAX" line. Monitor coolant and transmission fluid levels regularly for the next 50 to 100 miles of driving, and top off as necessary.
