Recently the water pump in my Stratus failed. The bearings on the pump's sprocket broke and coolant seeped by the sprocket into the crankcase. This quickly diluted all the oil, boiled the coolant and the steam from it travelled up the engine (don't ask how) and condensed in the air filter. This restricted the airflow and at the first intersection the car chugged and died.
Luckily the water outlet's gasket gave way and the internal pressure was released, with much of the oil and coolant mixture ending up on top of the engine.
This could have been prevented. The FSM for the car clearly states that if excessive coolant is seeping through the pump's weeping hole and is drying up and turning black then the pump needs replacement.
So if you notice coolant on you garage's floor or if there's lots of black gunk on the AC housing and the oil pan then it may be time to replace your timing chain and water pump.
Click images to enlarge

When the engine fires, it spins the crankshaft located at the bottom of the engine. On one end the crankshaft connects to the transmission which moves the wheels, but on the other it drives a chain which in turn rotates the water pump sprocket and the engine's cams. Rotating the cams opens the intake and exhaust valves at the right times needed for ignition and exhaust gas evacuation.
The valves are on the top part of the engine and open down into the cylinder, similar to how a bicycle nipple opens into the tire and lets air out. They are timed to open while the piston is at the bottom part of the cylinder. An incorrect repair can disturb this timing and cause the valves to open down into the cylinder while the piston is moving up through it, striking and bending the valves (besides other damage).

The 2.7 engine has both the timing chain and the water pump on the inside of the engine. To access it, it is required to remove the timing chain cover, which also acts as an engine mount, mounting the engine to the frame of the car. With the mount removed, the engine must be supported by a jackstand placed under the oil pan.
It took me about 2 weeks nights and weekends to complete the project. It's about 10-14 hours of work. Parts and tools were about $700. Here in the Bay Area I got quotes of about $2600+. So consider this before moving on... Also consider that a common problem with some models is sludging and a faulty tensioner leading to timing chain failure. So you may want to first check the condition of the engine by removing the front valve cover and checking for any sludge buildup. It there's lots of it then it might not be worth replacing the chain.

New parts:

• Water pump and chain replacement kit -- the chain, sprockets, water pump have been changed. Order from a dealer the kit with the latest part number.
• Cams,
• Guides,
• Tensioner if needed
• Water pump.
• Lower gasket set
• Valve cover gaskets
• Crankshaft sprocket
• Oil pump
• Hoses
• Accessory belt tensioner puck.
• New cam position sensor
• Spark plugs if required

Supplies:

• Engine degreaser
• Coolant, as much as 10 qts
• New radiator drain cock, once the old one comes off, it doesn't seal as well when you put it back
• Engine oil and filter
• Penetrating oil
• Working and disposable gloves
• Kneepads
• Parts bins for 120 fasteners, clips and spacers, labeled (I used paper coffee cups)
• Carboard

Special tools:

• 10 mm long socket
• 15 mm socket
• Impact wrench
• 12mm L-shaped hex wrench
• Work lights
• Torx wrench set
• Trim and panel removal kit

To rent (from Autozone):

• puller 27078 for the crankshaft sprocket
• torque wrench 27173
• hoist chain
• Chrysler harmonic dampener puller 27139