The Lemon Index
200420061st generation
Worse than average · most complaints: electrical
28 owner complaints, first 3 years 17–18 mpg combined, EPA
Similar cars, same year
2005 Lexus LS2005 Volvo S40 1602005 Jaguar X-Type
Lemon Index: 100 = the average car, lower is better.
When problems show up
Most problems on this year showed up between 14,000 and 38,000 miles (22,000–62,000 km) (the middle half of the 21 complaints, of all 28 filed so far, that listed a mileage).
- At 60K, 100K and 150K miles (97K, 161K and 241K km) Past the range where most problems showed up: it has likely had them or dodged them, so repair records matter most.
This is when owners who had a problem reported it, not the odds that one car will have it.
Questions to ask the seller
- Were recalls 07V589000 (transmission & drivetrain), 06V125000 (suspension) and 06V020000 (fuel system, gasoline) done? Ask for the dealer printout, or check the VIN.
- Do all the lights, screens and power features work? Has the battery, alternator or any wiring been replaced?
- Do the seats adjust, heat and lock in place properly?
- Any oil burning, leaks or check-engine lights? Ask for oil-change records.
- Cadillac sent dealers 626 repair notes for this car. Was this one done: “Diagnosing a no crank and no start condition due to discharged battery”?
From this year's own recalls, top problems, top repair bills and Cadillac's repair notes. Recall repairs are free at any dealer.
How serious. Out of all 28 owner complaints filed so far (every year since it was sold, not just the first 3), owners reported:
“Average car” = what the same number of complaints would include at the rate across every model year we track. Owners report these themselves; NHTSA doesn't confirm the cause.
What owners complain about most. From owner complaints to the government.
Share of this year's owner complaints filed with NHTSA, not the share of cars that break. One complaint can name more than one area.
Check engine light on? Look up any code →
When owners reported problems. From owner complaints to the government.
Most owners who filed a complaint with NHTSA had 13K to 38K miles (22K to 62K km) on the car (21 of all 28 complaints filed so far listed the miles). This shows when people who had a problem reported it, not the odds that your car will have it.
In owners' words
The consumer has problems with the vehicle not wanting to start. The consumer was told that since the vehicle is completely electric that sometimes the circuits or transmitters blow out, 2005 Cadillac STS.
2005 Cadillac STS owner · NHTSA complaint 10156284
More owner reports
2005 Cadillac STS. Check engine light comes on after repeated attempts to fix. Code po171, po174.
NHTSA complaint 10188482
2005 Cadillac STS indicator illuminated on the dashboard stating "vehicle speed limited to 80 miles per hour".
NHTSA complaint 10142150
Fixes owners look up most.
From 200 YouTube videos · 5.1M views · 2005–2011 Cadillac STS
Most-watched topics
- Windows, doors & mirrors146K views
2006 Cadillac STS door handle micro switch repairNoNonsenseKnowHow · 94K views · 4 videos - Transmission & shifter87K views
2005 - 2011 Cadillac STS Console removal and shifter repairCamaro Mods Channel · 70K views · 3 videos - Death wobble & steering78K views
2006 Cadillac STS 4 POWER STEERING PUMP REPLACEMENTslow_restoration · 53K views · 2 videos - Steering & suspension48K views
2005 Cadillac STS front end rattle strut replacementJasonDoesDIY · 48K views
Show 4 more
- Infotainment, battery & electrical42K views
2005-2011 Cadillac STS - How to Start Vehicle with a Dead Key Fob BatteryYOUCANIC · 32K views · 3 videos - Oil changes & service30K views
2005-2011 3.6L V6 Cadillac STS - Oil Change and Oil Filter ReplacementYOUCANIC · 18K views · 2 videos - No-start: theft light, key & ignition27K views
DIAGNOSING A NO START 2007 CADILLAC STS WON'T CRANK...CLICKS...SOLVED...Peter L · 17K views · 2 videos - Heat, A/C & blend door27K views
How to Replace Cabin Air Filter 2006 Cadillac STS | AQ1042Filterheads · 16K views · 2 videos
Before you buy, watch
Top 5 Problems Cadillac STS Sedan 1st Generation 2005-111A Auto: Repair Tips & Secrets Only Mechanics Know · 174K views
Cadillac sts 2007 computer problemsKyle M · 76K views
2008 Cadillac STS Review - Kelley Blue BookKelley Blue Book · 220K viewsViews show how many people looked up each fix, not how often it breaks. Videos belong to their creators; we link to them. The 2005 is the same generation.
Costs are the middle (median) of the dollar amounts people say out loud in these videos, so one wild number can't swing it. They aren't verified bills or sales; real prices depend on year, miles, condition and where you live. Tap Hear it to jump to the moment.
Problems Cadillac told dealers about
Cadillac sent dealers 626 repair notes for this car. The ones about its biggest problems:
- Diagnosing a no crank and no start condition due to discharged battery
- Bulletin-sit-bulletin-1652151
Ask a seller or mechanic if these were done. Some are free under warranty or a special program.
Recalls 3
- Transmission & drivetrain · recall issued 2007
ON CERTAIN PASSENGER VEHICLES, THE REAR AXLE PINION SEAL DOES NOT MEET ALL OF THE SPECIFICATIONS AND MAY EXPERIENCE A FLUID LEAK.
- Suspension · recall issued 2006
CERTAIN VEHICLES HAVE A LEFT OR RIGHT REAR SUSPENSION TOE LINK THAT COULD SEPARATE BECAUSE OF AN INCORRECT WELD.
- Fuel system, gasoline · recall issued 2006
CERTAIN VEHICLES EQUIPPED WITH V6 ENGINES MAY HAVE A CONDITION WHERE FUEL IS NO LONGER SUPPLIED TO THE ENGINE.
Recall repairs are free at any dealer. A recall only matters if it's still open on that exact car, so check its VIN.
Canada? See recalls at Transport Canada
Government investigations
- ClosedFailure of the rear differential2007
NHTSA looks into a problem when enough owners report it. Many end in a recall.
Safety
Crash stars (older test): front — · side — · rollover —
Fuel cost and engines
About $3,350–$4,400 (USD) a year in fuel (EPA estimate at U.S. prices, 15,000 miles or 24,000 km a year). Engines: 3.6L 6-cyl, 4.6L 8-cyl.
Every Cadillac STS year. 2005 is highlighted. Lower is better.
Newest year first. Red = worse than average, gray = about average or too few complaints to score. #1, #2… = that year's YouTube rank among the 5 Cadillac STS years with enough videos (#1 = the year owners and reviewers talk about most positively). It is not a reliability rank.
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<iframe src="https://lemonindex.com/embed/cars/cadillac-sts/?y=2005" title="Cadillac STS reliability by model year (The Lemon Index)" width="100%" height="261" style="border:0;max-width:720px" loading="lazy"></iframe><p style="font-size:13px;margin:4px 0 0">Data: <a href="https://lemonindex.com/cars/cadillac-sts/2005/">Lemon Index</a> (2005 Cadillac STS reliability)</p>Quick answers
Is the 2005 Cadillac STS reliable?
No, it is worse than average by government complaints. It drew a bit more than the average car's complaints filed with NHTSA in its first 3 years, per car sold (Lemon Index 121; 100 is average, lower is better).
What are the most common 2005 Cadillac STS problems?
In owner complaints to the government, the parts named most are electrical (39%), seats (14%) and engine (11%). That is the share of complaints, not the share of cars that break.
How many recalls does the 2005 Cadillac STS have?
3 safety recalls (latest: transmission & drivetrain). Recall repairs are free at any dealer; check a specific car's VIN at nhtsa.gov/recalls.
What gas mileage does the 2005 Cadillac STS get?
17 to 18 mpg combined, depending on the engine (EPA estimate).
At what mileage do 2005 Cadillac STS problems show up?
Most problems on this year showed up between 14,000 and 38,000 miles (22,000–62,000 km) (the middle half of the 21 complaints, of all 28 filed so far, that listed a mileage). At 60K, 100K and 150K miles, a 2005 is past the range where most problems showed up: it has likely had them or dodged them, so repair records matter most. This is when owners who had a problem reported it, not a prediction for one car.
Does the 2005 Cadillac STS have transmission problems?
Transmission and drivetrain issues aren't among its top 5 complaint areas.
How much does the 2005 Cadillac STS cost in fuel a year?
About $3,350 to $4,400 a year, by the EPA's current estimate.
What engines does the 2005 Cadillac STS have?
3.6L 6-cyl, 4.6L 8-cyl.
The Lemon Index counts owner complaints filed with the U.S. government (NHTSA) in a car's first 3 years, per car sold, against the average car of the same model years (100 = average, lower is better). It measures complaints, not crash safety. A complaint is an owner's report, not a confirmed defect. How it works