Buick Regal Engine Intake Air Temperature (IAT) Sensor Guide: 1986-2005
If your Buick Regal is running rough, getting poor gas mileage, or has a check engine light on, a bad intake air temperature sensor could be the culprit.
- A bad IAT sensor on a Regal commonly triggers Check Engine Light codes P0112 or P0113.
- Symptoms directly impact driveability, including poor gas mileage, rough idle, and hard starts.
- First, identify if your sensor is a simple standalone unit in the intake tube or integrated into the more expensive MAF sensor.
- For standalone sensors, replacement is a very easy 15-minute DIY job.
Is Your Regal's IAT Sensor Failing?
A faulty Intake Air Temperature (IAT) sensor sends bad data to your engine's computer. This can cause a variety of noticeable problems. Because the computer can't properly adjust the fuel mixture, you'll often see a drop in performance and efficiency.
Common Symptoms of a Bad IAT Sensor:
- Check Engine Light: This is the most common sign. The ECU will log a fault code, typically P0112 or P0113. 🎬 Watch: How to diagnose these specific IAT fault codes.
- Poor Fuel Economy: If the sensor tells the computer the air is colder than it is, the engine will run rich (too much fuel), wasting gas.
- Rough Idle: An unbalanced air-fuel mixture can cause your Regal's engine to idle unevenly or stumble.
- Hard Starting: The engine may be difficult to start, especially in cold weather, because the fuel mixture isn't right for the conditions.
- Reduced Engine Power & Hesitation: With incorrect data, the engine can't perform optimally, leading to sluggish acceleration and hesitation.
Standalone Sensor vs. Integrated MAF Sensor
For the 1986-2005 Buick Regal, the IAT sensor comes in two main styles depending on your specific year and engine (like the 3.8L V6):
- Standalone Sensor: On many models, the IAT is a separate, two-wire sensor that plugs directly into the plastic or rubber air intake tube, somewhere between the air filter box and the throttle body. These are simple to access and replace.
- Integrated MAF/IAT Sensor: On some later models, the IAT sensor is built into the Mass Airflow (MAF) sensor assembly. If the IAT portion fails on an integrated unit, the entire MAF sensor assembly must be replaced. This is a more expensive part.
Pro Tip: To check which type you have, follow the air intake tube from the air filter box. Look for a small plastic sensor with a two-wire electrical connector plugged into the side of the tube. If you find one, you have a standalone sensor. If not, it is likely integrated into your MAF sensor, which is located right after the air filter housing.
🎬 Watch: See exactly where the IAT sensor is located.Choosing the Right Aftermarket IAT Sensor
When replacing the IAT sensor on your Regal, you don't necessarily need to buy the most expensive option. However, since this sensor plays a key role in engine management, choosing a quality part is important.
OEM vs. Aftermarket Quality:
The original part for your Buick is an ACDelco or GM Genuine part. While ACDelco is the gold standard, high-quality aftermarket brands offer reliable performance, often at a better price. For a simple sensor like the IAT, a reputable aftermarket part is a smart choice. Forum discussions among GM owners often show confidence in brands like Delphi (a frequent original supplier to GM), Standard Motor Products, and NTK.
Brand Tiers for Your Regal:
- Standard Ignition: As a brand under Standard Motor Products (SMP), Standard is a well-regarded aftermarket manufacturer known for producing reliable electronic components that meet or exceed OEM specifications. This is a solid choice for a dependable, long-lasting repair.
- True Tech: This brand typically falls into the economy or budget-friendly category. While it offers a cost-effective solution to get your car running properly, it may not have the same long-term durability or stringent quality control as a premium aftermarket or OEM brand.
Known Issues, Recalls, and Service Bulletins
Searches of the National Highway Traffic Safety Administration (NHTSA) database did not find any specific recalls or Technical Service Bulletins (TSBs) for a failing Intake Air Temperature sensor on 1986-2005 Buick Regal models. However, several recalls were issued for these vehicles for other issues, most notably for an engine fire risk on 1997-2003 models where oil could leak onto the exhaust manifold (NHTSA Recall 08V-118). This issue is unrelated to the IAT sensor's function.
| Part Type | Estimated Cost |
|---|---|
| New Aftermarket (Standalone) | $19.54 - $42.24 |
| New OEM (ACDelco, Standalone) | $40 - $65 |
| Shop Labor | $48 - $70 |
| Integrated MAF/IAT Sensor Assembly | $200 - $283+ (Part & Labor) |
Frequently Asked Questions
Is the IAT sensor hard to replace on a Buick Regal?
If you have a standalone sensor, the replacement is very easy and requires no special tools. It is located on the air intake duct, held in by a rubber grommet. You simply disconnect the electrical plug, pull the old sensor out, push the new one in, and reconnect the plug. The entire job can take less than 15 minutes.
🎬 See this quick walkthrough for replacing the sensor yourself.What do the fault codes P0112 and P0113 mean?
These are the most common codes for a bad IAT sensor. P0113 (Circuit High Input) means the computer is seeing a higher than expected voltage, which it interprets as an extremely cold temperature (like -40°F). P0112 (Circuit Low Input) means the computer sees a very low voltage, which it interprets as an extremely high temperature. Both conditions cause the computer to use the wrong fuel mixture.
Can I just clean the IAT sensor?
Sometimes, the sensor probe can get dirty with oil or carbon buildup, which can affect its reading. You can try cleaning it carefully with an electrical parts cleaner. If the sensor has failed internally, which is common with age, cleaning will not fix the problem and it must be replaced.
What's the difference between an IAT sensor and a coolant temperature sensor?
The IAT sensor measures the temperature of the air entering the engine. The Engine Coolant Temperature (ECT) sensor measures the temperature of the engine's coolant. The ECU uses both signals, but for different calculations. A bad ECT sensor will cause different symptoms and fault codes.
Helpful Videos
Technical Specifications
OEM Part Numbers: 25036751 25171651 97381182
The Intake Air Temperature sensor is a negative temperature coefficient (NTC) thermistor. Its electrical resistance decreases as the air temperature increases. It typically has a 2-pin rectangular connector and is mounted in the air intake stream.
We Have This Part in Stock
The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.
- Buick Regal: