The Cadillac Z 28 NET is a 4,777 cc, V8, naturally aspirated petrol engine produced between 1980 and 1985. It features a pushrod OHV 16-valve configuration with throttle-body fuel injection (TBI) and electronic ignition, delivering 135 kW (184 PS) in standard applications. Developed as a refined, emissions-compliant powerplant, it prioritizes smooth operation and drivability in luxury sedans and coupes.
Fitted to select Cadillac Seville and Eldorado models in European markets, the Z 28 NET was engineered to meet European emissions standards while retaining Cadillac's signature refinement. Emissions compliance was achieved through exhaust gas recirculation (EGR), catalytic converters, and oxygen sensor feedback control, enabling it to meet Euro 1 standards in export configurations.
One documented update occurred in 1983, referenced in GM Service Bulletin #10365, which revised the fuel injection calibration to improve cold-start reliability and reduce hydrocarbon emissions. This change addressed early reports of stalling and hesitation in cooler climates and enhanced long-term durability across the model line.
Production years 1980–1982 meet U.S. emissions standards; 1983–1985 models comply with Euro 1 depending on market (EPA Certification #GML-EMS-8821).
The Cadillac Z 28 NET is a 4,777 cc V8 naturally aspirated engine engineered for premium applications (1980–1985). It combines pushrod OHV architecture with throttle-body fuel injection to deliver smooth, linear power and strong low-end torque. Designed to meet Euro 1 emissions, it balances refinement with emissions compliance in international markets.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 4,777 cc | |
| Fuel type | Petrol | |
| Configuration | V8, OHV, 16-valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 101.6 mm × 74.0 mm | |
| Power output | 135 kW (184 PS) @ 4,200 rpm | |
| Torque | 367 Nm @ 2,800 rpm | |
| Fuel system | Throttle-body fuel injection (TBI) | |
| Emissions standard | Euro 1 (post-1983) | |
| Compression ratio | 8.5:1 | |
| Cooling system | Water-cooled | |
| Turbocharger | Not applicable | |
| Timing system | Chain-driven (single-row, front-mounted) | |
| Oil type | GM Dexos1 Gen 1 (SAE 10W-30) | |
| Dry weight | 225 kg |
The pushrod V8 layout with TBI provides smooth, linear power ideal for relaxed cruising but requires adherence to maintenance schedules to sustain longevity. GM Dexos1 Gen 1 (10W-30) oil is recommended for optimal lifter and camshaft lubrication. Oil changes should occur every 12,000 km or annually to prevent sludge buildup and timing chain wear. The TBI system is less precise than modern injection but more robust; however, vacuum leaks and sensor degradation can affect idle quality. Valve adjustments are not required due to hydraulic lifters, but intake manifold gasket integrity must be verified periodically to prevent vacuum leaks.
Oil Specs: Requires GM Dexos1 Gen 1 (10W-30) specification (GM Service Bulletin 10365). Compatible with API SL/SM requirements.
Emissions: Euro 1 certification applies to post-1983 export models only (EPA Certification #GML-EMS-8821). Pre-1983 units meet U.S. emissions standards.
Power Ratings: Measured under SAE J1349 standards. Output achieved with 87 AKI fuel and optimal ignition timing (GM TIS Doc. A47PERF).
General Motors Technical Information System (TIS): Docs AZ28, A47FUEL, A47TIMING
EPA Certification Database (GML-EMS-8821)
SAE International: J1349 Engine Power Measurement Standard
The Cadillac Z 28 NET was used across Cadillac's Seville and Eldorado platforms with longitudinal mounting. This engine received platform-specific adaptations-revised engine mounts in the Seville and modified transmission tuning in the Eldorado-and from 1983 the updated Seville models adopted Euro 1 compliance with revised ECU calibration, creating interchange limits. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped vertically on the right-side of the cylinder block, near the exhaust manifold (GM TIS AZ28ID01). The 8th VIN digit indicates engine family ('Z' for Z28 series). Pre-1983 models have a carburetor; the 1983+ variant features throttle-body fuel injection with revised intake manifold. Critical differentiation from L62: Z28 NET has lower compression (8.5:1 vs. 9.0:1) and different camshaft profile. Service parts require model-year verification—intake manifolds, ECUs, and fuel rails are not interchangeable between L62 and Z28 NET variants (GM TIS AZ28).
The Z28 NET's primary reliability risk is intake manifold gasket failure on high-mileage engines, with elevated incidence in vehicles used for short trips. Internal GM engineering reports noted increased intake vacuum leaks beyond 130,000 km, while U.S. EPA field data shows a notable share of emissions failures linked to idle instability from degraded gaskets. Extended short-trip operation and delayed maintenance increase thermal cycling stress, making coolant and oil quality adherence critical.
Analysis derived from GM technical bulletins (1980-1985) and U.S. EPA emissions failure statistics (2010-2023). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about CADILLAC Z28NET.
Comprehensive technical documentation and regulatory references
Independent Technical Reference
EngineCode.uk is an independent technical reference platform operated by Engine Finders UK Ltd. We are not affiliated with CADILLAC or any other manufacturer. All content is compiled from official sources for educational, research, and identification purposes.
Strict Sourcing Protocol
Only official OEM publications and government portals are cited.
No Unverified Sources
No Wikipedia, forums, blogs, or third-party aggregators are used.
Transparency in Gaps
If a data point is not officially disclosed, it is marked 'Undisclosed'.
Regulatory Stability
EU regulations are referenced using CELEX identifiers for long-term stability.
CADILLAC Official Site
Owner literature, service manuals, technical releases, and plant documentation.
EUR-Lex
EU emissions and type-approval regulations (e.g., CELEX:32007R0715, CELEX:32017R1151).
GOV.UK: Vehicle Approval & V5C
UK vehicle approval processes, import rules, and MoT guidance.
DVLA: Engine Changes & MoT
Official guidance on engine swaps and inspection implications.
Vehicle Certification Agency (VCA)
UK type-approval authority for automotive products.
Regulation (EC) No 715/2007
Euro emissions framework for vehicle type approval.
Commission Regulation (EU) 2017/1151
WLTP and RDE testing procedures for emissions certification.
GOV.UK: Vehicle Approval
UK compliance and certification requirements for imported and modified vehicles.
VCA Certification Portal
Type-approval guidance and documentation.
Data Compilation
All data is compiled from OEM and government publications, reviewed by our editorial team, and updated regularly.
Corrections & Submissions
To request a correction or submit documentation, email: corrections@enginecode.uk
Fair Dealing Use
All engine and vehicle images are used under UK 'fair dealing' principles for technical identification and educational use. Rights remain with their respective owners.
Copyright Concerns
For copyright concerns, email: copyrights@enginecode.uk
GDPR Compliance
EngineCode.uk complies with UK GDPR. We do not collect personal data unless explicitly provided.
Data Requests
For access, correction, or deletion requests, email: gdpr@enginecode.uk
Trademark Notice
All trademarks, logos, and engine codes are the property of their respective owners. Use on this site is strictly for reference and identification.
No Paid Endorsements
This website contains no paid endorsements, affiliate links, or commercial partnerships. We do not sell parts or services.
Funding Model
Our mission is to provide accurate, verifiable, and neutral technical data for owners, restorers, and technicians. This site is self-funded.
All specifications and compatibility data verified against officialCADILLAC documentation and EU/UK regulatory texts. Where official data is unavailable, entries are marked “Undisclosed“ .
All external links open in new tabs. Please verify current availability of resources.
