Guide to the 1991-1996 Buick Commercial Chassis Intake Manifold Temperature Sensor
Experiencing poor fuel economy or a rough idle? Your Intake Manifold Temperature Sensor could be the culprit.
- A bad IAT sensor commonly causes a Check Engine Light, poor gas mileage, and rough idling.
- Replacement is a simple, DIY-friendly task that takes less than 30 minutes.
- Quality aftermarket brands like Standard Ignition offer a reliable and cost-effective alternative to more expensive OEM parts.
- There are no known recalls or technical service bulletins (TSBs) specifically for this sensor on the Commercial Chassis.
Symptoms of a Failing Intake Manifold Temperature Sensor
When the IAT sensor on your Buick Commercial Chassis begins to fail, it sends incorrect information to the engine's computer. This can lead to a range of noticeable performance issues. Because the computer can no longer correctly calculate the air-fuel mixture, the engine may run too rich (too much fuel) or too lean (not enough fuel).
Common Failure Symptoms:
- Check Engine Light: This is often the first and most obvious sign of a problem. A diagnostic scan may reveal codes like P0112 (Circuit Low Input) or P0113 (Circuit High Input).
- Poor Fuel Economy: If the sensor incorrectly reads the air as being colder than it is, the computer will inject more fuel than necessary, causing you to use more gas.
- Rough Idle: An incorrect air-fuel mixture can make the engine idle unevenly or roughly, especially during warm-up.
- Hard Starting: The engine may be difficult to start, particularly in cold weather, if the computer isn't providing the correct fuel mixture for a cold start.
- Hesitation or Loss of Power: During acceleration, you might notice a hesitation or a general lack of power because the engine isn't getting the optimal fuel mixture for the load demand.
Choosing the Right Aftermarket Sensor
For a vehicle like the 1991-1996 Buick Commercial Chassis, which shares its platform with the Buick Roadmaster, you don't need to source an expensive OEM part from a dealer. Quality aftermarket brands provide reliable and cost-effective replacements that meet or exceed original specifications. For a straightforward but critical part like the IAT sensor, a trusted aftermarket brand is a smart and economical choice.
Brand Options
- Standard Ignition (Standard Motor Products): Standard is a highly-regarded brand in the aftermarket industry. They are known for producing parts that are a direct fit and perform reliably. Their sensors undergo 100% factory testing to ensure they work correctly right out of the box, making them a dependable choice.
- True Tech: While reviews for the specific "True Tech" parts brand are scarce, "TrueTech Automotive" is a name associated with repair shops that are generally well-regarded for honesty and fair pricing. When considering a brand with less public data, focus on the seller's return policy and warranty.
Pro Tip: The IAT sensor for these vehicles is often a simple, two-wire thermistor. The technology is not complex, and a quality aftermarket part from a reputable manufacturer like Standard Ignition will perform just as well as the original GM part for a fraction of the price.
Typical Replacement Costs
Replacing the IAT sensor is an affordable repair. The part itself is inexpensive, and the labor involved is minimal.
| Part/Service | Estimated Cost |
|---|---|
| New Aftermarket Sensor | $19.54 - $42.24 |
| Shop Labor | $50 - $100 |
| Total Estimated Cost | $70 - $142 |
Frequently Asked Questions (FAQ)
Where is the IAT sensor located on the 1991-1996 Buick Commercial Chassis?
On the V8 engines used in these vehicles (like the 5.0L, 5.7L L05, and 5.7L LT1), the Intake Air Temperature sensor is typically screwed directly into the intake manifold, near the front of the engine. It is a small, two-wire sensor that is easily accessible.
Can I replace this sensor myself?
Yes, this is a very DIY-friendly repair. It usually requires only basic hand tools. The process involves unplugging the electrical connector, unscrewing the old sensor, screwing the new one in, and reconnecting the electrical plug. The entire job can typically be completed in under 30 minutes.
What happens if I don't replace a bad IAT sensor?
While the vehicle will still run, ignoring a bad sensor will lead to ongoing issues like poor fuel economy, rough engine performance, and increased emissions. In some cases, an overly rich fuel mixture can lead to long-term problems like carbon buildup on internal engine components or damage to the catalytic converter.
Are there any recalls for this sensor?
There are no specific recalls for the Intake Manifold Temperature Sensor on the 1991-1996 Buick Commercial Chassis. Broader searches on the NHTSA website also show no relevant recalls for this component on related GM vehicles of this era.
Technical Specifications
OEM Part Numbers: 12110319 25171651 88864354
Typically a 2-terminal, screw-in sensor. The connector is a rectangular plug-in type.
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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 Commercial Chassis: