Welcome to On Site Auto Repair!
Auto Repair in Sonoma, CA
Auto repair in Sonoma, CA offering brake repair, oil changes, check-engine diagnostics, AC service, tire replacement and rotations, wheel alignments, battery and starter testing, suspension and steering work, and scheduled maintenance for cars and light trucks.
Visit our Sonoma, CA location today for exceptional auto repair services!
Our Auto Repair Services in Sonoma, CA
Brake Repair Sonoma, CA
Need Brake Repair in Sonoma, CA? Stop safely on Highway 12, around Sonoma Plaza, and on steep Sonoma Mountain grades with pad and rotor service, drum repair, fluid flushes, calipers, and ABS diagnostics. We diagnose pulsation, squeal from dusty vineyard roads, spongy pedals after winter rains, and brake fade on summer drives. Expect same-day repairs, clear estimates, and parts that fit Toyota, Subaru, Honda, Ford, and Chevy models locally. Schedule service to keep errands and winery trips on track. Choose Brake Repair in Sonoma, CA for fast, accurate results. Your search for Brake Repair in Sonoma, CA ends here today.
Radiator Repair Sonoma, CA
Overheating on Highway 12 or climbing Trinity Grade? Radiator Repair in Sonoma, CA pinpoints leaks, clogged fins, weak thermostats, and failing water pumps before engine damage. We diagnose coolant loss, pressure-test the system, verify fan operation, and restore proper temperature for Toyota, Honda, Ford, Chevy, Subaru, Lexus, Acura, Hyundai, and more. Get leak detection, radiator repair or replacement, coolant flushes, hose and belt service, and thermostat and water pump replacement. Sonoma heat, vineyard dust, and slow plaza traffic strain cooling systems—fix issues fast so you don’t miss work or tasting-room reservations. Book Radiator Repair in Sonoma, CA service today.
Check Engine Light Repair Sonoma, CA
Get precise Check Engine Light Repair in Sonoma, CA when that amber icon pops on during Highway 12 commutes, winery deliveries, or stop‑and‑go near the Plaza. We scan OBD-II codes, verify live data, and run smoke tests to pinpoint EVAP, misfire, O2 sensor, catalytic, or fuel-trim faults, helping you pass Sonoma County smog checks. Technicians explain findings, prioritize fixes, and reset readiness monitors correctly, avoiding repeat test failures. We address issues caused by dusty vineyard roads, cold morning starts, and heat-soaked summer traffic. Schedule Check Engine Light Repair in Sonoma, CA for diagnosis, transparent estimates, and drives across Sonoma Valley.
Auto AC Repair Sonoma, CA
Need Auto AC Repair in Sonoma, CA? Beat heat on Hwy 12 and cool down after vineyard runs with precise diagnostics, R-134a/R-1234yf recharge, compressor and condenser repair, evaporator replacement, and dye leak detection. We also restore heat and defrost for foggy mornings with heater core, thermostat, and blend door service. Technicians use scan tools and manifold gauges to pinpoint airflow issues, fans, weak vents, and musty odors from clogged cabin filters—common after dusty harvests. Book seasonal checks before summer weekends. Choose local pros who know Sonoma traffic patterns: Auto AC Repair in Sonoma, CA keeps you comfortable all year.
Oil Change Sonoma, CA
Need an Oil Change in Sonoma, CA? We service commuters on Hwy 12, vineyard workers driving backroads, and families making short trips around the Plaza. Fresh oil protects engines from heat, stop-and-go idling, and dust intrusion, improving fuel economy and cold-start performance. We use OEM-spec oil and filters for Toyota, Subaru, Honda, and domestic trucks, follow warranty requirements, check fluids, belts, and batteries, and recycle used oil under Sonoma County guidelines. Choose convenient scheduling and pricing; get back on the road before traffic builds. Book an Oil Change in Sonoma, CA today to keep your car ready for winery runs.
Suspension Repair Sonoma, CA
Need Suspension Repair in Sonoma, CA? Worn shocks, bent control arms, and leaking struts show up on Highway 12, Arnold Drive, and rutted vineyard lanes—causing tire cupping, clunks, pulling, and shaky steering at speed. We inspect bushings, ball joints, tie rods, sway bar links, and steering racks; replace struts/shocks; correct alignment; and road-test on routes to verify tracking and even tire wear. Improve braking stability on winter roads, reduce vibration over plaza speed bumps, and protect tires. Schedule Suspension Repair in Sonoma, CA and get clear estimates, quality parts, and fast turnaround. Choose local Suspension Repair in Sonoma, CA.
Tire Shop Sonoma, CA
Searching for a Tire Shop in Sonoma, CA that fixes Highway 12 vibration and vineyard-road punctures quickly? We mount tires to factory torque, replace valve stems, perform computer balancing, repair punctures correctly, and service TPMS so warning lights stay off on cold Sonoma mornings. Choose Michelin, Bridgestone, Goodyear, or Continental matched to your runs between the Plaza and Santa Rosa. Our technicians diagnose pull, shimmy, and uneven wear from potholes after winter rains. Need flat repair or full replacement today? Visit Tire Shop in Sonoma, CA for precise installs that reduce shake on Arnold Drive and keep commutes safe.
Transmission Repair Sonoma, CA
Need Transmission Repair in Sonoma, CA? We diagnose slipping, rough shifts, delayed engagement, and leaks caused by Highway 12 commutes, Trinity Grade climbs, and stop‑and‑go on Broadway. Our technicians service automatic and manual units on Ford, Chevy, Toyota, Honda, Subaru, Lexus, Hyundai, and more. Get fluid exchanges, filter replacement, clutch work, CV joint and axle repair, transfer case service, and rebuilds when needed. We use diagnostics to pinpoint faults, saving you visits. We offer towing if your car won’t move. Start with free transmission diagnostics or schedule now: Transmission Repair in Sonoma, CA keeps you moving across the Valley.
About Our Auto Repair Shop in Sonoma, CA
On Site Auto Repair in Sonoma, CA provides mobile auto repair at your location, including diagnostics with OBD-II scanning, battery testing and replacement, starters and alternators, brake pad and rotor replacement, fluid leaks, belt and hose replacement, radiator and cooling system service, oil changes, spark plugs and ignition coils, and check-engine light troubleshooting. Technicians handle no-starts, overheating, and roadside minor repairs across Sonoma and nearby areas. Appointments are scheduled by phone, with clear estimates before work and parts sourced to match your vehicle’s specifications.
About Sonoma, CA
Sonoma, CA blends early mission-era roots with a compact, walkable downtown centered on the historic Sonoma Plaza. Residents and businesses benefit from steady tourism, local agriculture, and accessible civic services. Notable landmarks include Sonoma State Historic Park, Sonoma City Hall, Sonoma Valley Hospital, Mission San Francisco Solano, and the Fairmont Sonoma Mission Inn & Spa. Technicians arrive to neighborhoods from Boyes Hot Springs to Maxwell Farms Regional Park with the right parts and tools, handling roadside diagnostics, battery swaps, brake repairs, and fluid leaks on-site. They navigate Sonoma Plaza traffic and winery access roads, schedule around tasting-room hours, and use low-profile lifts for tight driveway clearances common near historic cottages and vineyard estates.
Sonoma's population is 10,739. City center coordinates: 38.2919, -122.4580. The city sees warm, dry summers, cool wet winters, and morning marine fog that affects batteries, belts, and braking components. On Site Auto Repair prioritizes coolant flushes for summer heat, corrosion checks from moisture, and tire inspections for temperature swings, while following California BAR standards, CARB parts rules, and smog-related repair documentation. In Boyes Hot Springs, we handle brake and battery issues on-site. Fetters Hot Springs–Agua Caliente gets tune-ups and diagnostics. Temelec sees scheduled maintenance for senior communities. El Verano benefits from quick tire and fluid services. Diamond A receives roadside troubleshooting. We use recycled materials and sustainable methods where possible, reduce waste responsibly, and support Sonoma’s community through local sourcing and volunteer initiatives. Trusted by drivers across Sonoma, CA. For reliable Auto Repair services in Sonoma, contact On Site Auto Repair today.
Cities We Serve
Neighborhoods We Serve
Things to Do
Sonoma Plaza
Sonoma State Historic Park
Sonoma TrainTown Railroad
Sonoma State Historic Park
Sonoma Valley Museum of Art
Sonoma Coast State Park
Sonoma Botanical Garden
Buena Vista Winery
Montini Open Space Preserve
Maxwell Farms Regional Park
Sonoma Garden Park
Sonoma Barracks
Sonoma Overlook Trail
Sonoma
Sonoma Family Fun Center
Vallejo Home
Sonoma County
Montini Open Space Preserve trailhead
Chateau Sonoma
Bartholomew Park
Transportation
Sonoma Plaza
Sonoma Valley Hospital
Sonoma Marketplace (on West Napa)
W MacArthur & Broadway (Ac Sonoma Vly HS)
2nd St W & Sonoma Marketplace
2nd St West & Sonoma Marketplace
Boyes Hot Springs (Sonoma Mission Inn)
Sonoma Valley Unified School District Bus Yard
Sonoma Valley Hospital
E Broadway & MacArthur (Ac Sonoma Vly HS)
Broadway & Maple St
2nd St W & Andrieux (Sonoma Medical Ctr)
Driving Directions
Driving Directions from Mike Larbre Automotive to On Site Auto Repair
Driving Directions from Metric Motors Auto Repair to On Site Auto Repair
Driving Directions from Broadway Auto Care to On Site Auto Repair
Driving Directions from El Verano Auto Repair to On Site Auto Repair
Driving Directions from Pacific Rim Auto Repair to On Site Auto Repair
Driving Directions from Sonoma Truck And Auto Service to On Site Auto Repair
Driving Directions from Eagle Automotive Sonoma, LLC to On Site Auto Repair
Driving Directions from Steve's Smog & Auto to On Site Auto Repair
Driving Directions from Lambert 76 to On Site Auto Repair
Driving Directions from Sonoma Mobile Auto & Tire Repair to On Site Auto Repair
Driving Directions from Auto Tech n' Tire to On Site Auto Repair
Driving Directions from G & C Auto Body, Inc. to On Site Auto Repair
Driving Directions from Wine country auto center & Tires sonoma to On Site Auto Repair
Driving Directions from Anton's European Car Service to On Site Auto Repair
Driving Directions from Oil Changers to On Site Auto Repair
Driving Directions from Auto Tech to On Site Auto Repair
Driving Directions from DeWitt's Tire & Brake to On Site Auto Repair
Driving Directions from Sonoma Motors Inc to On Site Auto Repair
Driving Directions from Tire repair mobile assistance to On Site Auto Repair
Driving Directions from Mike's Alignment & Brake to On Site Auto Repair
Frequently Asked Questions
Our certified mechanics answer the most common car repair questions to help you stay informed and confident. Explore our FAQs for honest, expert advice trusted by Santa Rosa drivers.
Do you provide loaner cars or shuttle service?
While we don't provide loaners, we're located in downtown Santa Rosa's Railroad Square with easy access to shopping, dining, and public transportation while you wait.
Can you work on my vehicle if it's still under warranty?
Absolutely! We perform warranty-compliant maintenance and repairs. We use OEM or equivalent parts to maintain your vehicle's warranty coverage.
How do I know if I really need the recommended service?
We provide detailed explanations and show you exactly what needs attention. We never pressure you into unnecessary repairs - our reputation depends on honest service.
Do you offer payment plans for major repairs?
We accept cash, check, and all major credit cards. For major repairs, we can discuss payment options that work for your budget.
What if my car breaks down outside of business hours?
Call our main number (707) 326-8655 and leave a message. We'll get back to you first thing in the morning to arrange service.
ReviewsWhat Our Clients Say
Brands We ServiceAuto Repair Brand
Toyota Repair
Honda Repair
Ford Repair
Chevrolet Repair
Nissan Repair
Mercedes Repair
Lexus Repair
Acura Repair
Infiniti Repair
Kia Repair
Hyundai Repair
Subaru Repair
Mazda Repair
Volkswagen Repair
Contact Info
Location
363 W 9th St B & C
Santa Rosa, CA 95401
Phone
707-326-8655
Hours
- Monday-Thursday: 7:30 AM - 4:30 PM
- Friday: 7:30 AM - 12:00 PM
- Saturday: Closed
- Sunday: Closed
New Customer Special:
$25 off your first service over $100. New customers only. One per household. Mention this offer when you call. Valid through December 31, 2026.
Oil Change Special:
Full synthetic oil change for $69.99. Includes up to 5 quarts of oil and a new oil filter. Most cars and light trucks. Valid through December 31, 2026.
Free Brake Inspection
Free brake inspection. We check pads, rotors, fluid, and lines and give you a written report. No purchase required.
Latest News
Why Is My Car’s Fuel Pump Failing in Windsor? What Sonoma County Drivers Need to Know About Fuel Delivery Problems
If your car is sputtering, stalling, or struggling to start in Windsor or anywhere in Sonoma County, a failing fuel pump might be the culprit. Here’s how to recognize the warning signs, what to expect from repair, and why catching it early saves you from getting stranded.
Why Is My Car’s Power Window Not Working in Petaluma? What Sonoma County Drivers Need to Know About Window Regulator and Motor Problems
A power window that won’t move, moves slowly, or makes grinding noises isn’t just an inconvenience — it can also be a safety and security issue. If your window is stuck open near Petaluma or anywhere in Sonoma County, here’s what’s likely going on and what to do about it.
Why Is My Car’s Oxygen Sensor Failing in Rohnert Park? What Sonoma County Drivers Need to Know About O2 Sensor Problems
If your check engine light is on and your gas mileage has taken a nosedive, a failing oxygen sensor could be the reason. Here’s what Rohnert Park and Sonoma County drivers need to know about O2 sensor symptoms, what replacement actually involves, and when to get it handled before it turns into a bigger repair.
Why Is My Car’s CV Axle or CV Joint Clicking in Petaluma? What That Popping Sound Means for Sonoma County Drivers
That clicking or popping sound when you turn your car in Petaluma isn’t something to ignore — it’s usually a worn CV joint, and catching it early can save you from a much bigger repair bill. Here’s what’s actually happening inside your drivetrain, what warning signs to watch for, and when to get it checked.
Why Does My Car Smell Like Something’s Burning in Petaluma? What Those Weird Odors Are Actually Telling You
A burning smell coming from your car is never something to ignore — and in Petaluma and throughout Sonoma County, drivers deal with specific conditions that can make these smells worse. Here’s how to figure out what that odor is actually coming from, and when you need to get it checked right away.
Why Is My Car’s Thermostat Failing in Rohnert Park? What Sonoma County Drivers Need to Know
A failing thermostat might seem like a small problem, but it can quietly lead to overheating, poor fuel economy, and expensive engine damage. If you’re driving in Rohnert Park or anywhere in Sonoma County, here’s how to recognize the warning signs early and what to do about it.
Why Is My Car’s Starter Motor Failing in Petaluma? What Sonoma County Drivers Need to Know About No-Start Problems
If you turn the key and hear a click, a groan, or nothing at all, your starter motor could be the culprit. Here’s how to tell what’s actually going on — and what Petaluma and Sonoma County drivers should do about it.
Why Is My Car’s Engine Misfiring in Petaluma? What Drivers in Sonoma County Need to Know
An engine misfire can feel like a stumble, shudder, or loss of power — and if you’re driving through Petaluma or anywhere in Sonoma County, ignoring it can lead to costly damage. Here’s what actually causes misfires, what the warning signs look like, and when it’s time to bring your car in.
Why Are My Tires Wearing Unevenly in Cotati? What Sonoma County Drivers Need to Know About Tire Wear Patterns
Uneven tire wear is more than a cosmetic issue — it’s usually a sign that something mechanical is off with your vehicle. If you’re driving in Cotati, Rohnert Park, or anywhere in Sonoma County and noticing bald edges, center wear, or cupping on your tires, here’s what’s actually causing it and what to do about it.
Why Is My Car’s Water Pump Failing in Sebastopol? What Sonoma County Drivers Need to Know
A failing water pump is one of the most overlooked causes of engine overheating in Sonoma County. If you’re driving in Sebastopol or anywhere around West County, here’s how to spot the warning signs before a small problem turns into a very expensive repair.
Read More About Our Auto Mechanic Services
On Site Auto Repair in Santa Rosa is a full service auto mechanic shop. Our auto mechanics are certified and are here to help with all of your repair needs. No auto repair job is too big or too small for On Site Auto Repair. We handle all types of auto repair, including regular maintenance, engine repair, brake work, and troubleshooting. If you are looking for honest and reliable auto mechanics, give us a call today. Ask us about our new customer specials.
Vehicles are usually described as 5 speed or 6 speed, meaning they have that many gear ratios. Those gears let the vehicle travel across the full range of speeds and use the engine's power efficiently. Transmissions are complex and are in constant use, so they take a lot of wear and tear. Many owners also forget to check and change the fluid on a regular schedule. That is why transmission problems are so common. At On Site Auto Repair in Santa Rosa, our transmission technicians can diagnose, repair, or replace your transmission. If you are looking for an honest transmission repair shop, give us a call today.
There are several warning signs that your vehicle can give you before your brakes may reach the point of potential failure or extensive repair. Whether composed of ceramic, semi-metallic, or organic materials, brake pads erode each time you depress the brake pedal. If the pads wear down too much without being replaced, the metal housing for the pads will make contact with the metal rotors (or drums), which may produce not only a safety issue but a situation where the rotors/drums are required to be replaced as a result of the prolonged contact of metal parts without the pad buffer. If you are in need of an affordable brake repair mechanic in Santa Rosa, please do not hesitate to schedule an appointment today!
Vehicle Inspection In Santa Rosa
The key to top notch automotive repair and troubleshooting lies in a thorough understanding of what’s actually going on under the hood. Sure, you know that a radiator keeps your engine cool, but understanding how it keeps it cool is the key to solving technical problems efficiently. If you know which parts perform what function, your powers of diagnosis will be much more powerful.
Radiator Inspection Service In Santa Rosa
Ensuring that your vehicle’s engine cooling system is in proper operating condition is extremely essential to engine life and performance. Operating at excessive temperatures can lead to premature engine wear. Your vehicle’s engine cooling system should be checked periodically, and a radiator coolant flush is also recommended to prohibit radiator corrosion. On Site Auto Repair will thoroughly drain and power flush the old coolant and particulates, and refill the cooling system with your vehicle manufacturer’s recommended coolant.
Our Santa Rosa Service Area – Directions to On Site Auto
Proudly serving drivers throughout Santa Rosa neighborhoods, from Railroad Square to Bennett Valley, and extending our trusted auto repair services to Petaluma, Sebastopol, Windsor, and all of Sonoma County.
Auto Repair Services We Offer in Santa Rosa, CA
Our shop at 363 W 9th St B & C handles a wide range of repairs and maintenance for drivers across Santa Rosa and Sonoma County.
Engine Diagnostics and Check Engine Light
A check engine light means your car is reporting a fault. We connect an OBD-II scanner, read the fault codes, and explain what they mean in plain language. We diagnose the problem first, then tell you what the repair will cost.
Oil Change Service
We do full-synthetic and conventional oil changes. We use the viscosity grade your manufacturer specifies, such as 5W-30, 5W-20, or 0W-20, and we replace the oil filter every time.
Brake Repair and Replacement
Worn brake pads squeak. Worn rotors grind. A soft brake pedal is a warning. We inspect and replace brake pads, rotors, and calipers using OEM-quality and aftermarket parts, depending on your budget.
Battery, Alternator, and Starter Repair
We test your battery with a load tester, not just a voltage check. We also test the alternator and starter, because a failing alternator will kill a new battery quickly.
AC and Heating Repair
If your AC is not blowing cold, we recharge the refrigerant and check for leaks. If your heat is not working, we diagnose the cause and repair it.
Scheduled Maintenance and Tune-Ups
We handle spark plug replacement, belt inspection and replacement, air and cabin filter replacement, fuel system service, coolant flushes, and transmission fluid service. If you are not sure what your car is due for, we look it up by make, model, and mileage.
Tire Rotation and Inspection
Uneven tire wear affects handling, fuel economy, and tire life. We rotate your tires, measure tread depth, inspect the sidewalls, and check the pressure.
Pre-Purchase Inspection
Thinking about buying a used car? We check the brakes, belts, fluids, undercarriage, and suspension, and we run a diagnostic scan for hidden fault codes. Call for current pricing.
Why Santa Rosa Drivers Choose On Site Auto Repair
Free estimates. You know the cost before we start any work.
Same-day appointments available. Call and we will tell you what we can fit in today.
ASE Certified mechanics. Credentialed professionals with real diagnostic tools.
Convenient location. We are in Railroad Square, minutes from downtown Santa Rosa, with shops and restaurants in walking distance while you wait.
Ready to Book?
Call (707) 326-8655 or send us a message with your vehicle and what is going on with it. We will give you a free estimate before we schedule anything.
On Site Auto Repair — 363 W 9th St B & C, Santa Rosa, CA 95401. Serving Santa Rosa, Petaluma, Rohnert Park, Sebastopol, Windsor, Healdsburg, and Sonoma County.
Things To Do In Santa Rosa, CA
From exploring the Charles M. Schulz Museum and Luther Burbank Home & Gardens to enjoying outdoor adventures at Spring Lake Regional Park and Annadel State Park, Santa Rosa offers endless opportunities for family fun, Wine Country experiences, and recreational activities that keep our community vibrant year-round.
Santa Rosa Transportation to On-Site Auto Repair
Conveniently located in the historic Railroad Square district with easy access from Highway 101, our auto repair shop is just minutes from downtown Santa Rosa, Santa Rosa Plaza, and all major neighborhoods, with nearby public transit options and walkable access to local shops and restaurants while your vehicle is being serviced.
Contact On-Site Auto Repair Today
Ready to experience honest, reliable auto repair in Santa Rosa?
Whether you’re dealing with a check engine light, need routine maintenance, or facing an unexpected breakdown, our ASE-certified mechanics are here to help. We serve drivers throughout Santa Rosa and Sonoma County with the same commitment to quality and honesty that has made us the area’s most trusted auto repair shop.