My 2003 Dodge Intrepid is over hearing and I've replaced the thermostat, water pump, timing chain, radiator and the heater hose assembly. I'm clueless as to what I should check now

It definitely was not a sparkplug. It is either the water pump, thermostat or clogged heater core.

Why do you need to replace thermostat.? Is it not getting hot enough via the heater,or is the engine water boiling? Its usually at the end of the bottom hose nowadays,youll see a round housing,two or three bolts.Drain the water first,or undo the bolts,engine cold,and catch the water.Replace with an original thermostat,and double check the sealing ring is in place on the new one.Refill radiator.Run engine,check water level later,with heater on hot

Hope this helps you....

Instructions

1. Prepare the Dodge Intrepid
   • 1 Lay out a drop cloth underneath the Dodge Intrepid to protect the floor from coolant spills. Designate an area to lay out each part alongside its bolts and connecting hoses and wires. Use a drop cloth here as well, some of the parts will have traces of grease and coolant.
     
   • 2 Disconnect the negative battery cable, using a screwdriver to unscrew the clamp that secures the cable to the negative (-) post. Pull the cable away from the battery post.
     
   • 3 Use a jack to elevate the Dodge Intrepid and jack stands to shore up the jack. Release the pressure in the radiator by removing the cap. Take out the drain plug located underneath the radiator. Catch the coolant in a resealable container
     
   • 4 Use a grease pencil to mark on the timing belt its position in each pulley before removal. This will save time when reinstalling. If needed, replace the timing belt and skip marking the old one.
     
   Remove the Damaged Pump
   • 5 Locate the water pump on the Dodge Intrepid. It's mounted on the front of the engine block and connected to the radiator and various other parts through a series of hoses. It's rotated by the timing belt. Study these parts, as you'll have to remove them.
     
   • 6 Disconnect or remove the parts in front of the water pump, using an adjustable wrench. In the most common Dodge Intrepid engine--the 2.7L--you'll find, in order: the upper radiator crossmember, fan module, accessory drive belts, crankshaft damper, timing cover, timing chain and guide wires.
     
   • 7 Unbolt the water pump from the engine block, using an adjustable wrench. You may have to use a chisel to gently break the seal between the mount and the pump. Discard both the pump and the bolts.
     
   • 8 Clean off the mounting area with a shop rag.
     
   Install the New Pump
   • 9 Inspect the new water pump to ensure it's identical to the old pump and free of any metal splinters or debris.
     
   • 10 Arrange the new water pump on the mount. You won't need sealant for the o-ring on a Dodge Intrepid. Hold the water pump and o-ring in place as you secure it with the new bolts. Tighten them with a torque wrench to 105 inch pounds torque in any order.
     
   • 11 Install the timing belt and wires, using the grease pencil marks to guide you in installation. Install the rest of the parts in the order removed. The camshaft must be reconnected with a torque wrench at 125 foot pounds torque.
     
   • 12 Replace the radiator's drain plug and refill the radiator with the amount and type of coolant specified in your owner's manual. Release the jack and jack stands.
     
   • 13 Attach the negative battery cable to the post and tighten the screw on the clamp. Crank the Dodge Intrepid's engine and check for leaks. Then, close the hood.
     

Read more: How to Install a Water Pump in a Dodge Intrepid ' eHow.com http://www.ehow.com/how_4508707_install-water-pump-dodge-intrepid.html#ixzz29Q1ZC1uZ

Hi, I don't have a picture, but trace the big hose from the bottom of the radiator to the engine, and it will be under the housing where the hose connects.

2.7L Engine

1. Disconnect negative cable.
   CAUTION Do not remove pressure cap with the system hot and under pressure because serious burns from coolant can occur.
   
2. Drain cooling system.
3. Remove radiator lower hose from thermostat housing.
4. Remove nuts from heater tube flange studs.
5. Loosen starter bolt at heater tube bracket.
6. Pull heater tube out of thermostat housing and position out of the way.
7. Remove bolt and two studs.
8. Remove thermostat housing, O-ring and thermostat.
9. Remove thermostat housing bolts.

To install:

1. Clean gasket sealing surfaces.
   NOTE Install thermostat with the bleed valve located at the 12 o'clock position, between tabs on seal.
   
2. Install thermostat and seal into thermostat housing .
3. If removed, install two studs.
4. Install thermostat, thermostat housing and O-ring and bolt. Tighten attaching bolts to 105 inch lbs.(12 Nm).
5. Lubricate new heater return tube O-ring with coolant.
6. Position heater return tube flange over two studs. Install nuts.
7. Tighten retaining nuts to 53 inch lbs.(6 Nm).
8. Tighten starter bolt to 40 ft. lbs. (54.3 Nm).
9. Connect the lower radiator hose to the thermostat housing. Install hose clamps.
10. Refill cooling system.
11. Inspect for leaks.
12. Connect negative cable.

replace the cap--is the radiator damaged? No reason to replace the water pump. Boiling is caused by leak, faulty thermostat, clogged radiator, or head gasket.

You can check yourself at this link. There is an estimator that indicates labor will be from $450 to $570. Then you can check out mechanincs in your area.

This is a big job. The water pump is driven by the timing chain and it involves taking everything off the front of the engine. Don't be surprised if the mechanic also recommends replacing other items while in there. If you have more than 100,000 miles, maybe even the timing chain(s). As long as it's apart . . .

Its behind the front pulleys,behind the timing chain/belt cover.

follow your top radiator hose to the motor, where that goes in is the thermostate housing. unbolt it and put a new one thermostat in the same way the old one came out. and replace the gasket or oring

Hello Kalel6877...the "quickest" way is let a shop put it on a hoist and do it...but if you want to tackle this one i'll walk you through it.
Raise your Dodge Intrepid with a jack and lower onto jack stands, or use wheel ramps. Set parking brake and/or chock wheels
Disconnect the negative cable from the battery. Open the drain plug at the bottom of the radiator and drain the coolant into a suitable container.
On Intrepids with 2.7L engines, follow the lower radiator hose to the thermostat housing. Loosen the hose clamp at the end of the radiator hose with a screwdriver and pull the hose off the thermostat housing.
Unbolt the two bolts holding the thermostat housing cover on and pull off the cover. On 2.7L Intrepid engines, it is easier to gain access to the thermostat housing behind the alrernator by working from beneath the engine.
Note the position of the old thermostat and remove. Install the new thermostat with the spring-side facing into the engine. Clean any old gasket residue from inside the thermostat housing cover. Install the new thermostat gasket.
Reinstall the thermostat housing cover and tighten bolts to 105 inch/pounds. Reattach the radiator hose and tighten the hose clamp. Refill the radiator with reserve or new coolant. Reattach the negative battery cable.
Start your Dodge Intrepid and allow it to run with the heater on high until it reaches normal operating temperature. Check radiator hose for leaks and tighten the hose clamp to stop any leaks, if necessary.
Thats about it...jack her down and pat yourself on the back.
Good luck..i hope this helps...please take time to rate me a fixya.

possible bad heater core