1977 Triumph Stag 3.0L Petrol · YRW 788S
1977 Triumph Stag (3.0L, petrol). First registered 16 Feb 1977. Recorded mileage 62,151 miles. MOT valid until 25 May 2027.
- Make & Model
- TRIUMPH STAG
- Year / Origin
- 1977 · Sheffield
- Safety Recall
- Unknown
- MOT Status
- Valid until 25 May 2027
- Road Tax
- —
- Recorded Mileage
- 62,151 mi
- ULEZ Compliance
- Check Required (Pre-Euro 4 Petrol)
- Fuel & Engine
- Petrol · 3.0L
- Reliability Guide
- Common Faults
Thinking of buying this vehicle? Free MOT and tax checks do not cover legal ownership. If outstanding finance exists, finance companies have legal right to repossess without compensation.
YRW 788S Key Findings
- 5 MOT tests recorded
- Latest MOT passed on 30/04/2026
- 62,151 miles recorded at latest MOT
- 1 historical MOT failure
- No defects recorded at the latest MOT
Derived directly from the recorded DVSA and DVLA data shown on this page.
YRW 788S MOT History
Interpretation generated from the recorded test data above — not an official DVSA statement and not a substitute for an independent inspection.
5 MOT tests are recorded for this 1977 Triumph Stag (YRW 788S) between May 2023 and April 2026.
The record contains 4 passes and 1 failure.
The most recent test on 30 April 2026 was a pass, although the earlier record includes 1 failure that buyers may want to investigate.
Across all tests, the most frequently flagged areas are: Suspension (1 issue). Repeated mentions in one area can indicate an ongoing pattern worth checking in person.
In total 4 advisory notices are recorded. Advisories flag items that passed but may need attention before the next test; they are not evidence of how well the vehicle has been serviced.
YRW 788S Mileage History
- 17/05/202355,039 mi
- 23/05/202456,390 mi+1,351 mi
- 23/05/202456,390 mi
- 08/05/202558,562 mi+2,172 mi
- 30/04/202662,151 mi+3,589 mi
Average of roughly 2,407 miles per year across 5 recorded odometer readings.
Technical Specifications
Core Specifications
Identification & Status
Dimensions & Weights
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Known faults for Triumph Triumph Stag
Our database tracks 4 specific mechanical faults and recurring failure patterns identified across UK MOT testing stations for this generation.
MOT Roadworthiness: Good
This rating reflects historical MOT pass rates and recurring advisory wear patterns from official DVSA test logs. Note that roadworthiness does not verify outstanding finance, insurance write-offs, or stolen records.
Verify lender finance agreements, insurance write-offs, police stolen registers, and mileage rollback.
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TRIUMPH STAG Model Intelligence & Reliability
Verified MOT failure trends, buying advice, and technical directory specifications.
Owner-reported defects, recurring MOT failure points, and estimated repair costs.
Browse production generations, registration statistics, and trim variants.
Historical MOT pass rates and DVLA records for 1977 model year cars.
- V8 cooling system overheating and warped alloy cylinder headsSerious
The bespoke 3.0-litre Triumph V8 suffered notorious overheating due to a high-mounted water pump that easily air-locked if coolant dropped, narrow engine water passages, and casting sand left in blocks from the factory. Furthermore, cylinder head studs entered the block at two opposing angles, producing lateral stress when hot that readily warped the aluminium heads and breached head gaskets.
- Duplex timing chain stretch and tensioner failureSerious
The Triumph 3.0-litre V8 uses long single-row duplex chains to drive each overhead camshaft from a jackshaft. The timing chains stretch with use, and hydraulic tensioners wear or fail when oil changes are neglected or oil pressure drops. A stretched chain causes severe valve timing deviation, can jump teeth on sprockets, or snap completely, causing catastrophic piston-to-valve collision in the interference engine.
- Bodyshell structural corrosion in sills, floors and A-pillarsSerious
Constructed from untreated 1970s British Leyland steel with complex multi-box sections, the Stag body is highly prone to structural tinworm. Water leaks through weathered targa and windscreen seals soak into cabin carpets, rotting out inner and outer sills, floorpans and the crucial A-pillars behind front trim panels. Corroded sills cause the open body tub to flex and sag, misaligning doors and weakening the roll hoop structure.
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