The 2005 Buick Terraza is a GM minivan on the long-wheelbase Lambda-predecessor platform, sharing DNA with the Uplander and Montana. Known for catastrophic 3.5L V6 engine failures and transmission cooling system issues that can destroy both major drivetrain components if ignored.
Symptoms: Excessive oil consumption (1 qt per 500-1,000 mi), Blue smoke from exhaust on startup or acceleration, Knocking/ticking noises from lower engine, Sudden loss of compression and dead cylinder, Check engine light with misfire codes P0300-P0306
Fix: This 3.5L suffers from piston ring land failure and carbon buildup that scores cylinder walls. Temporary fixes (top-end work) fail quickly. Real solution is complete engine rebuild (40-50 hrs) or reman long-block swap (18-24 hrs). Most shops recommend replacement over rebuild given core condition.
Estimated cost: $4,500-7,500
Transmission Oil Cooler Line Failure and Cross-Contamination
Common · high severity
Typical onset: 70,000-120,000 mi
Symptoms: Pink milkshake appearance in coolant reservoir, Transmission slipping or delayed engagement, Engine overheating, Coolant loss with no external leaks, Transmission failure shortly after coolant contamination noticed
Fix: The internal trans cooler inside the radiator fails, allowing coolant into ATF and vice versa. Requires radiator replacement, full cooling system flush, transmission fluid flush minimum (2-3 hrs). If contamination went unnoticed for any period, transmission rebuild/replacement is mandatory (12-16 hrs additional). Catch it early or face $5k+ total repair.
Estimated cost: $800-1,200 if caught early; $4,000-6,500 with transmission damage
Transmission Mount Collapse
Common · medium severity
Typical onset: 60,000-100,000 mi
Symptoms: Heavy clunk when shifting from Park to Drive or Reverse, Vibration through floor at idle, Transmission appears to 'drop' when accelerating from stop, Visible sag of transmission when inspected on lift
Fix: The rear transmission mount deteriorates and allows excessive drivetrain movement. Requires trans support and mount replacement (2.5-3.5 hrs). Often discovered during oil changes. Unrelated to but often confused with the oil cooler issue above.
Estimated cost: $350-550
Fuel Filter Clogging and Pump Strain
Occasional · medium severity
Typical onset: 90,000-130,000 mi
Symptoms: Hesitation or stumble during acceleration, Hard starting when fuel tank below 1/4, Loss of power on highway grades, Fuel pump whine audible in cabin
Fix: The inline fuel filter (when equipped) or in-tank strainer clogs from debris in aging fuel systems. Filter replacement is 0.8-1.2 hrs if external; in-tank pump/strainer requires tank drop (3-4 hrs). Many owners skip the filter service and kill the pump by 150k mi.
Estimated cost: $180-280 for filter; $650-950 for pump replacement
Intake Manifold Gasket Coolant Leaks
Occasional · medium severity
Typical onset: 70,000-110,000 mi
Symptoms: Coolant smell from engine bay, Slow coolant loss requiring top-offs, White residue around intake manifold seams, Possible rough idle if coolant enters cylinders
Fix: The composite intake manifold gaskets deteriorate and leak coolant externally or internally. Requires intake removal and gasket set replacement (4-5 hrs). Not as catastrophic as the oil cooler issue but accelerates if combined with overheating from that failure.
Estimated cost: $550-850
EVAP Vent Valve and Purge Solenoid Codes
Occasional · low severity
Typical onset: 80,000-140,000 mi
Symptoms: Check engine light with P0449, P0455, P0442 codes, Fuel tank difficult to fill (pump clicks off repeatedly), Fuel smell near rear of vehicle, No drivability issues
Fix: The EVAP vent valve behind driver side rear wheel rusts and sticks, or purge solenoid fails. Vent valve replacement is 1-1.5 hrs; purge solenoid near engine is 0.5-0.8 hrs. Annoying but not breakdown-inducing. Requires smoke test to confirm.
Estimated cost: $200-400
Power Sliding Door Module and Track Failures
Occasional · low severity
Symptoms: Door opens partially then reverses, Grinding noise during power door operation, Door won't latch or unlock, Error messages on DIC
Fix: The power sliding door motors, cables, and control modules are fragile. Requires door disassembly for cable/motor replacement (3-4 hrs per side) or module replacement (1.5 hrs). Rollers in tracks wear and bind. Many owners disable the power feature entirely.
Estimated cost: $450-900 per door
Owner tips
Check for coolant in transmission fluid and ATF in coolant at EVERY oil change—this can save you $5k if caught early.
Monitor oil consumption religiously after 70k mi; if burning more than 1 qt per 1,500 mi, start budgeting for an engine.
Replace transmission mount proactively at 60-70k mi to prevent stress on the already fragile 4T65-E transmission.
Use TOP TIER gas and replace fuel filter every 30k mi if you plan to keep it past 100k—the fuel system is intolerant of cheap gas.
Budget $2k-3k annually for repairs after 100k mi if keeping this vehicle; it's not a matter of 'if' but 'when' on the engine.
Avoid unless under 60k miles with documented trans cooler replacement and you're handy with a wrench—the 3.5L engine is a ticking time bomb and transmission cooler failure is nearly inevitable, making this a money pit after 100k.
AI-assisted summary drawn from NHTSA recall data, our labor-times database, and platform knowledge. Not a substitute for a pre-purchase inspection on a specific vehicle.
Fitment notes: Side post terminals; battery located under hood on driver side
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Every control module on the 2005-2007 Buick Terraza — where it lives, replacement time, and what it takes to program a replacement. Modules marked dealer / factory tool won't work after a part swap alone — budget for programming.
Electronic Brake Control Module (EBCM)2.0 hr R&Rrelearn only +0.3 hr▸ programming details
📍 Engine compartment, driver side frame rail near master cylinder, integrated with ABS hydraulic unit
🔧 GM Tech 2
⚠️ Brake bleeding and automated bleed procedure required after replacement
Body Control Module (BCM)1.5 hr R&Rdealer / factory tool +1.0 hr▸ programming details
📍 Behind center instrument panel, above center console, accessible by removing radio trim
🔧 GM Tech 2 with TIS2000/SPS
⚠️ Controls lighting, door locks, remote start; VIN and option configuration required
📍 Under driver seat, mounted to seat frame (if equipped with memory seats)
🔧 GM Tech 2
⚠️ Optional equipment; memory positions must be reprogrammed by user
Transmission Control Module (TCM)no coding
📍 Integrated within PCM (4T65-E transmission)
⚠️ Not a separate module; transmission control integrated into PCM
Theft Deterrent Module (TDM)no coding
📍 Integrated within BCM
⚠️ PassLock II system; theft deterrent functions handled by BCM
Electronic Power Steering Control Module (PSMC)no coding
📍 Not equipped - hydraulic power steering only
⚠️ Terraza uses conventional hydraulic power steering; no electronic module
Aftermarket tool coverage varies by software version and vehicle build — treat "aftermarket tool" rows as "usually possible" and verify against your tool maker's coverage list before promising a customer. Spot a wrong location or hour? Tell us — corrections ship fast here.
THE BRAUN CORPORATION HAS NOTIFIED NHTSA ABOUT A DEFECT IN CERTAIN MODEL YEAR 2005-2008 GENERAL MOTORS MOBILITY CONVERSION, HANDICAPPED ACCESSIBLE LOW FLOOR MINIVANS. DURING CONVERSION, THE DRIVER OR PASSENGER SIDE TRAILING ARM MODIFICATION MAY NOT HAVE BEEN ADEQUATELY WELDED.
Consequence: A SQUEAKING OR CLUNKING NOISE MAY DEVELOP. THE TRAILING ARM BUSHINGS MAY PREMATURELY WEAR AND THE TRAILING ARM MAY FRACTURE OR SEPARATE, ALLOWING THE REAR AXLE TO BECOME PARTIALLY SEPARATED FROM THE CHASSIS INCREASING THE RISK OF A CRASH.
Remedy: DEALERS WILL INSPECT AND WILL HAVE A SUPPLY OF RETROFIT PARTS AVAILABLE TO REMEDY THE VEHICLES FREE OF CHARGE. THE SAFETY RECALL BEGAN ON JUNE 4, 2010. OWNERS MAY CONTACT BRAUN AT 1-800-488-0359.
STEERING · 09E005000
2009-02-17
DORMAN IS RECALLING 979 STEERING KNUCKLES, DORMAN P/NOS. 697-902 AND 697-903, SOLD UNDER DORMAN'S "OE SOLUTIONS<SUP>TM</SUP>" BRAND NAME, AND NAPA P/NOS. 7-8502 AND 7-8503 WHICH WERE SOLD FOR REPLACEMENT USE ON THE VARIOUS VEHICLES LISTED ABOVE. A POTENTIAL MATERIAL OR DESIGN DEFECT COULD RESULT IN THE STEERING KNUCKLE BREAKING IN THE HUB AREA.
Consequence: A BROKEN STEERING KNUCKLE COULD RESULT IN LOSS OF STEERING CONTROL AND A POSSIBLE CRASH WITHOUT WARNING.
Remedy: DORMAN WILL NOTIFY OWNERS AND REPLACE THE DEFECTIVE STEERING KNUCKLES FREE OF CHARGE AND REIMBURSE THE REPAIR FACILITY OR OWNER FOR LABOR. THE RECALL BEGAN ON FEBRUARY 23, 2009. OWNERS MAY CONTACT DORMAN'S TOLL-FREE HOTLINE AT 1-800-523-2492 AND PRESS 5.
PARKING BRAKE · 05V287000
2005-06-20
CERTAIN SPORT UTILITY VEHICLES FAIL TO CONFORM TO THE REQUIREMENTS OF FEDERAL MOTOR VEHICLE SAFETY STANDARD NO. 135, 'PASSENGER CAR BRAKE SYSTEMS.' TO MEET THE STANDARD, THE VEHICLE MUST NOT MOVE FOR FIVE MINUTES WHEN STOPPED ON A STEEP HILL WITH THE PARKING BRAKE APPLIED AND THE VEHICLE IN NEUTRAL (N). SOME OF THESE VEHICLES FAILED THIS TEST.
Consequence: WHEN THE PARKING BRAKE IS RELEASED, THE DRIVER MAY NOTICE UNINTENDED BRAKING WHEN ACCELERATING, DECELERATING, OR COASTING, AND A NOISE COMING FROM THE REAR OF THE VEHICLE. UNINTENDED VEHICLE MOVEMENT COULD OCCUR INCREASING THE RISK OF A CRASH.
Remedy: DEALERS WILL INSPECT FOR PARKING BRAKE LEVER SLIPPAGE AT EACH REAR BRAKE CALIPER AND REPLACE THE CALIPER IF LEVER SLIPPAGE IS IDENTIFIED. THE RECALL BEGAN ON NOVEMBER 14, 2005. OWNERS MAY CONTACT BUICK AT 1-866-608-8080, CHEVROLET AT 1-800-630-2438, PONTIAC AT 1-800-620-7668, OR SATURN AT 1-800-972-8876.
Fuel economy (EPA)
City
16mpg
Highway
23mpg
Combined
18mpg
Fuel
Regular Gasoline
Capability & size
EPA class
Minivan - 2WD
Wiper blades
GMT200 platform minivan shared with Chevrolet Uplander, Pontiac Montana SV6, and Saturn Relay
Size-standard part numbers — verify your connector type before buying. Rear blades are model-specific; check the package's vehicle list.
Fuel economy figures are EPA data via fueleconomy.gov (median across matching trims). Performance figures are compiled estimates for the 2005 Buick Terraza 3.5L V6 and can vary by trim.
🔧 Database maintained under the daily editorial review of Chris Hackleman · Master Technician · 20+ years and Jeff Moore · Master Lexus & Toyota Mechanic · 20+ years.