Changing out a second generation Dodge Neon thermostat is a straight forward task that definitely falls in the DIY category.
A bad thermostat will cause a Dodge Neon or any car to overheat and needs replaced when bad.
As always call a mechanic if you don’t feel comfortable working on your own car.
Only a few tools are needed along with the thermostat which can be bought at any auto store or even on Amazon.
Items Needed
- Thermostat for a Dodge Neon (1999-2005).
- 10mm socket with an extension and ratchet.
- Large pair of pliers and screwdriver.
- Pan to catch leaking fluid.
- Thermostat gasket or silicon.
Note: The stock Neon thermostat has a rubber O-ring seal built onto its flange.
Note: Buy a stock temperature thermostat since the factory one opens at about 192 to 199 degrees F.
Note: The 2003 to 2005 SRT-4 2.4L turbo uses a different two-piece thermostat housing and this guide shows the 2.0L engine.
Steps to Replace Dodge Neon Thermostat (1999-2005)
- Be sure the car is cooled down and not hot. If the car is hot the coolant will be under pressure and can burst out scalding anyone nearby.
The thermostat is located on the left when looking into the engine compartment from the front. Place a pan under the car to catch any fluid that leaks out.
Note: Drain coolant from the radiator draincock until the level is below the thermostat before removing the housing.
Note: Antifreeze is poison to kids and pets so wipe up spills and take old coolant to a collection center.
- Remove the coolant cap and remove the hose clamp. Some hose clamps have a screw on clamp while others have a pinch type clamp that is removed with a pair of pliers.
A second small hose also needs to be removed.
- Two 10mm bolts hold the assembly into place and need to be removed.
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After the 10mm bolts are removed the housing will come off and the thermostat will be exposed.
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The next step is to remove the old thermostat from the housing and insert the new one. The housing should be cleaned of any debris.
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The new thermostat will have notches that are aligned when inserting it.
Note: Set the small air bleed vent in the thermostat flange facing up and lined up with the notch in the cylinder head.
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Both the thermostat housing and the engine should be cleaned so it can seal properly and not leak.
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Insert the new thermostat and gasket and put it back together.
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Reinstall the 10mm bolts and connect the hoses.
Note: Tighten the two housing bolts to 110 in-lbs (12.5 Nm).
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Fluid will need to be added which will change after the Neon has warmed up and water flows past the thermostat.
Note: Fill with a 50/50 mix of coolant and distilled water.
Note: Chrysler calls for Mopar 5 year/100,000 mile HOAT coolant on 2001 to 2005 Neons and it should not be mixed with other coolant types.
Note: Fill the coolant reserve bottle to the FULL HOT mark and recheck it after three or four warm-up and cool-down cycles.
The best way, in my experience, is to stuff a piece of newspaper (or equivalent) into the hole countersinking it so that anything scouring the mating surface will not catch on it or fall into the block’s water jackets.
Next, fairly lightly scrub the flange shaped flat mating surface until debris is removed. Then go back over fairly rigorously with Scotch Brite pad to smooth the surface.
Best case scenario? You have a small round drill attachment for said sand paper and Scotch Brite.
After all of that scrubbing, take the vacuum hose to your newspaper plug and suck it out. Try to sck all of the particulates away before getting it to pull the paper wad.
I took out my thermostat in my dodge due to it over heating. Now it never over heats and it still blows out hot air. Anyone know why? Just found it out before a new one in
What is the best way to clean the thermostat housing and the engine so it can seal properly. Is there a cleaner that needs to be used or do you just wipe it off till clean?
The best way, in my experience, is to stuff a piece of newspaper (or equivalent) into the hole countersinking it so that anything scouring the mating surface will not catch on it or fall into the block’s water jackets.
Next, fairly lightly scrub the flange shaped flat mating surface until debris is removed. Then go back over fairly rigorously with Scotch Brite pad to smooth the surface.
Best case scenario? You have a small round drill attachment for said sand paper and Scotch Brite.