Upper Intake Manifold with Gasket for Buick Regal (1996-2004) 3.8L

Direct-Fit Upper Intake Manifold Kit for 1996-2004 Buick Regal (W-body)

What it Does: The Upper Intake Manifold replaces the failure-prone factory nylon plenum on the 1996-2004 Buick Regal to eliminate unmetered vacuum leaks and prevent coolant intrusion into the intake runners.

The Stock Buick Regal Intake Plenum Failure

The factory GM 3800 Series II composite manifold suffers from a notorious vulnerability surrounding the Exhaust Gas Recirculation (EGR) passage chimney. Continuous thermal cycling from recirculated exhaust gases softens and erodes the OEM plastic wall separating the hot EGR stovepipe from surrounding coolant jackets. Over time, this material fatigue leads to pinhole fractures, unmetered vacuum leaks, and catastrophic coolant migration directly into the cylinders, risking hydraulic lock and degraded combustion efficiency on the W-body chassis.

The Engineering Solution

Molded from heat-stabilized, high-density polymer, this replacement upper manifold withstands intense underhood thermal expansion without localized warping or fatigue around the EGR port. Precision-engineered runner profiles maintain smooth manifold absolute pressure (MAP) dynamics and uniform cylinder air distribution. The kit integrates robust gasket sealing channels that seat the included heavy-duty port seals, preventing vacuum bypass and protecting your L36 engine from internal coolant consumption.

What's Included

• 1 Upper Intake Manifold (plastic)
• 1 Upper Intake Manifold Gasket with port seals
• Fuel pressure regulator spring
• Throttle body studs
• O-rings and fittings

Technical Specifications

Compatibility

• 1996-2004 Buick Regal 3.8L Gas Naturally Aspirated
• 1999 Buick Regal 3.8L Gas Supercharged

Frequently Asked Questions & Fitment Warnings

Does this fit the W-body Regal?

Yes, this is a direct fit for the 1996-2004 Buick Regal equipped with the GM 3800 Series II engine. Only the 3.8L V6 applications listed are covered; it does not fit other displacements, Series I engines, or unlisted model years.

What is the critical installation procedure for this intake?

Install only on a cool engine, replace all disturbed coolant O-rings, and torque all manifold fasteners to factory sequence specifications (89 in-lbs) to avoid cracking the composite flange.

The Buick Reliability Standard

Engineered for bulletproof daily operation, this plenum restoration cures the primary failure point of the 3800 platform, delivering consistent vacuum sealing, zero lean codes, and leak-free reliability.