1986-1989 Honda Accord AC Compressor: The Keihin vs. Nippondenso Guide

The Single Most Important Check: Keihin or Nippondenso?

How to Identify Your Compressor

The best way to know which compressor you have is to visually inspect the unit in your engine bay. While finding clear, labeled pictures for this specific vintage is difficult, forum discussions provide clues. Look for labels or stampings on the compressor body. Nippondenso units are often described as longer and more rounded, while Keihin units may appear more short and boxy. The Nippondenso model used is the 10PA15E. If you are unsure, take clear photos of your compressor, paying special attention to the labels and where the AC lines connect, and compare them to listings for used or remanufactured parts online.

Symptoms of a Failing AC Compressor

When an AC compressor starts to fail, it will usually provide several warning signs. Being aware of these can help you diagnose the problem before it leaves you sweating in traffic.

• No Cold Air: The most obvious symptom is a lack of cold air from the vents. If the compressor isn't pressurizing the refrigerant, the cooling cycle can't happen.
• Strange Noises: A grinding, whining, or squealing sound when you turn the AC on often points to failing internal bearings or a problem with the compressor's clutch. If the noise is constant, the pulley bearing may be bad, but if it only occurs when the AC is switched on, the problem is likely internal to the compressor.
• Leaking Fluid: The AC system uses a special oil (PAG oil) mixed with the refrigerant. If you see a greasy, often greenish residue on or around the compressor body, it's a sign that the seals have failed and refrigerant is leaking out.
• Compressor Clutch Not Engaging: The outer part of the compressor pulley has a clutch that engages to turn the compressor's internal components. If you turn on the AC and don't hear a distinct 'click' or see the center part of the pulley start spinning, the clutch may have failed. This can be an electrical issue or a mechanical failure of the clutch itself.
• Rapid Cycling: If the compressor turns on and off very frequently, it can be a sign of low refrigerant (from a leak) or a faulty pressure switch.

Known Issues for 1986-1989 Honda Accords

For a vehicle of this age, most issues are related to wear and tear. However, there are some common themes discussed by owners.

• Compressor Seizure: Keihin compressors, in particular, are noted by some owners to be prone to seizing. A seized compressor will often cause the engine to bog down or stall when the AC is turned on, and may cause the drive belt to squeal loudly or break.
• Catastrophic Failure ("Black Death"): If a compressor fails internally, it can send metal shavings and contaminated sludge throughout the entire AC system. This is known as "Black Death" because of the dark, grimy material that clogs lines, the condenser, and the expansion valve. If this happens, simply replacing the compressor is not enough. The entire system must be thoroughly flushed, and the receiver/drier and expansion valve must be replaced to prevent the new compressor from failing immediately.
• Recalls and TSBs: There are no specific recalls or Technical Service Bulletins (TSBs) from the NHTSA related to the AC compressor for the 1986-1989 Honda Accord. Recalls for this generation primarily concerned seat belts and fuel systems. Later model Accords had warranty extensions for AC condenser issues, but this does not apply to the 1986-1989 generation.

Buying a Used AC Compressor: What to Check

A high-quality, low-mileage used OEM compressor can be a reliable and cost-effective alternative to a new aftermarket part. Here’s what to look for when buying a recycled unit.

1. Confirm the Type: First and foremost, ensure you are buying the correct type (Nippondenso or Keihin) for your vehicle's existing setup. Bring a photo of your old compressor to compare.
2. Inspect the Pulley and Clutch: Spin the pulley by hand. It should rotate smoothly with a slight resistance but no grinding or roughness. Check the clutch face for signs of extreme heat, warping, or damage.
3. Check the Ports: The inlet and outlet ports where the AC lines connect should be capped or sealed. If they are open to the air, moisture and debris have likely entered the compressor, contaminating it and rendering it useless. Do not buy a compressor with open ports.
4. Look for Leaks: Inspect the body of the compressor, especially around the seams and where the clutch is mounted. Any signs of oily residue indicate a leak.
5. Ask About the Donor Vehicle: If possible, find out the mileage of the car the part came from. Lower mileage is always better. Also, ask if the AC was functional before the vehicle was dismantled. A part from a collision-damaged car is often a better bet than one from a car that was scrapped for mechanical failure.

Replacement Overview and Difficulty

Replacing the AC compressor is a moderately difficult job that requires specialized tools. While a skilled DIY mechanic can perform the physical swap, the system must be legally and properly evacuated of old refrigerant before starting and then vacuumed and recharged afterward.

• Difficulty Rating: 4 out of 5
• Key Steps:
  1. Have the refrigerant professionally recovered from the system.
  2. Disconnect the battery.
  3. Remove the accessory drive belt from the compressor pulley.
  4. Disconnect the electrical connector and the AC lines from the compressor. Be prepared to cap the lines immediately to prevent contamination.
  5. Unbolt the compressor from its mounting bracket and remove it.
  6. Add the correct amount and type of PAG oil to the new compressor.
  7. Install the new compressor, reconnecting lines (with new O-rings), the electrical connector, and the belt.
  8. Crucial: Replace the receiver/drier (also called an accumulator). This part absorbs moisture and filters debris, and a new one is required any time the system is opened.
  9. Have a professional vacuum the system to remove all air and moisture, then recharge it with the correct amount of refrigerant.

Cost Comparison

Prices can vary significantly based on brand, condition, and supplier. Labor costs for a professional installation typically range from $296 to $434.

Frequently Asked Questions (FAQ)