1987-1989 Dodge Shadow & Plymouth Sundance Radiator: A Buyer's and DIY Guide

Symptoms of a Failing Radiator

A failing radiator on a Dodge Shadow or Plymouth Sundance will make itself known through several distinct signs. Ignoring them can lead to severe engine damage.

• Engine Overheating: This is the most critical symptom. If the temperature gauge on your dashboard climbs into the red zone, your engine is running too hot. This can be caused by a clogged or leaking radiator that can no longer cool the engine effectively.
• Coolant Leaks: Finding puddles of brightly colored fluid (typically green, orange, or pink) under the front of your car is a sure sign of a leak. The leak could be from the radiator itself, which can develop cracks in its plastic end tanks or corrosion in its aluminum core, or from one of the connecting hoses.
• Sweet Smell: The coolant used in these vehicles (ethylene glycol) has a distinctively sweet smell. If you notice this odor after driving, it's a strong indicator that coolant is leaking and burning off on a hot engine component.
• Visible Steam from Hood: If you see white steam coming from the engine bay, pull over immediately. This often means coolant is leaking from a pressurized part of the system and hitting the hot engine, instantly turning to steam.
• Low Coolant Level: If you frequently have to add coolant to the overflow reservoir, you have a leak somewhere in the system. A bad radiator is a common cause.
• Discolored or Sludgy Coolant: The coolant should be a clean, bright color. If you look in the radiator or overflow tank and see a rusty, brown, or sludgy fluid, it indicates internal corrosion. This sludge can clog the narrow passages in the radiator, severely reducing its efficiency.

Diagnosing a Radiator Leak

If you suspect a leak but can't easily see it, the most effective diagnostic tool is a cooling system pressure tester. You can often rent these from auto parts stores.

1. Wait for the engine to cool completely. Never open a hot cooling system.
2. Remove the radiator cap and attach the pressure tester's adapter.
3. Pump the tester by hand to pressurize the system to the level specified on the radiator cap (usually 13-16 PSI).
4. Watch the gauge. If the pressure holds steady for 15-20 minutes, the system is sealed. If the pressure drops, there is a leak.
5. With the system pressurized, look and listen for leaks. Coolant may drip, spray, or hiss from the location of the leak, making it much easier to find. Check all hoses, the radiator seams, and around the water pump.
🎬 See what to do if you can't find the leak

Buying a Used Radiator for Your 1987-1989 Shadow or Sundance

For a vehicle of this age, a quality used OEM radiator is often a better value than a cheap, new aftermarket part. OEM parts were designed for a perfect fit and often used durable materials. Here’s what to look for when buying used.

Physical Inspection Checklist:

• Check the Plastic End Tanks: These are the most common failure point. Inspect them closely for any hairline cracks, especially around the hose connections and where the plastic meets the aluminum core.
• Look for Previous Leaks: Stains or a crusty, colored residue (white, green, or orange) indicate a past leak. Avoid radiators that show signs of previous repairs like epoxy or sealant.
• Inspect the Fins: A few bent fins are okay, but if large sections are crushed or corroded, it will block airflow and reduce cooling performance.
• Examine the Inlet and Outlet Necks: Ensure these are not cracked, crushed, or excessively worn.
• Look Inside: Peek through the filler neck and hose connections. If you see heavy, rusty-brown buildup or a thick, oily sludge, the radiator is likely clogged internally and should be avoided.
• Verify Mounting Points: Make sure all mounting brackets and tabs are intact and not broken.

Cost Comparison: Shadow & Sundance Radiator

Prices can vary significantly based on part type and who does the work. For a vehicle of this age, a used OEM part offers a great balance of quality and cost.

Related Parts to Replace with Your Radiator

When you replace your radiator, it's a good idea to replace other cooling system components that are inexpensive and easy to access while the system is drained.

• Radiator Hoses: The upper and lower radiator hoses become brittle and soft over time. Replace them.
• Thermostat: This is a cheap and critical part that regulates coolant flow. It's wise to replace it anytime you do major cooling system work.
• Radiator Cap: A new cap ensures the system holds the correct pressure. A faulty cap can cause overheating or coolant loss.
• Hose Clamps: Old clamps can lose their tension. New ones are cheap insurance against leaks.
• Coolant/Antifreeze: Never reuse old coolant. Refill with a fresh, new batch of the correct type for your vehicle.

Frequently Asked Questions (FAQ)

Technical Specifications and Part Numbers

While matching the vehicle's features (engine, trans, etc.) is the most important step, these are some of the OEM part numbers associated with radiators for the 1987-1989 Dodge Shadow and Plymouth Sundance. The presence of multiple numbers reflects the different variations made for these cars.

• 04266637
• 4266434
• 4266435
• 4266633
• 4266634
• 4266635
• 4401680

(List is based on initial data and cross-references from aftermarket suppliers).

Recalls and Service Bulletins

Searches of the National Highway Traffic Safety Administration (NHTSA) database did not show any safety recalls specifically related to the radiator for the 1987-1989 Dodge Shadow or Plymouth Sundance. Most recalls for these models concerned items like seat belts and airbags.