Welcome to On Site Auto Repair!
Auto Repair in Santa Rosa, CA — ASE Certified Mechanics
Certified mechanics providing honest, reliable auto repair services for all makes and models. Same-day service available.
✓ ASE Certified Mechanics – Expert technicians you can trust
✓ Free Estimates – Transparent pricing with no surprises
✓ Same-Day Service – Get back on the road fast
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.
Your Local Auto Repair Experts & Reliable Repairs
On Site Auto – Auto Repair Service in Santa Rosa, CA
At On Site Auto Repair, we take pride in delivering expert auto repair services with integrity and precision. Our certified mechanics have years of hands-on experience and are committed to keeping your vehicle running smoothly. Whether it’s brake repairs, transmission work, or routine maintenance, we treat every car like it’s our own. As a locally owned and operated shop in Santa Rosa, we’re here to serve our community with honest diagnostics, transparent pricing, and fast, dependable service. When you choose us, you’re not just a customer—you’re part of the On Site Auto Repair family.
Serving Santa Rosa Since 2011
★★★★★ 4.9/5 (117 Google Reviews)
What We DoComplete Auto Repair Services in Santa Rosa
From routine maintenance to complex repairs, we handle it all with precision and care. Trust our certified mechanics to keep your vehicle running smoothly and safely.
Brake Services
- Brake pads, rotors, fluid replacement
- Starting at $89
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Transmission Repair
- Automatic & manual transmission service
- Free diagnostic
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Engine Repair & Diagnostics
- Check engine light, fault code scanning, engine repair
- Free diagnostic scan
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Heating & AC Service
- Climate control repair, refrigerant service
- Stay comfortable year-round
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Steering & Suspension
- Shocks, struts, alignment service
- Smooth, safe driving
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Cooling System Service
- Radiator repair, coolant flush
- Prevent overheating
Why Choose UsWhy Choose On-Site Auto Repair in Santa Rosa?
Honest & Transparent
No upselling, just honest advice about what your car needs
ASE Certified Technicians
Our mechanics are ASE certified to work on all makes and models. We are licensed by the California Bureau of Automotive Repair, licence number [number].
Free Estimates & Diagnostics
Know what you’re paying before we start any work
Local Family Business
Proudly serving the Santa Rosa community with personalized service
On Site Auto Repair: Quick Facts
- What we are: An independent auto repair shop, not a dealership and not a chain.
- Where we are: 363 W 9th St B & C, Santa Rosa, CA 95401, in the Railroad Square district.
- Phone: (707) 326-8655
- Hours: Monday to Thursday 7:30 AM to 4:30 PM. Friday 7:30 AM to 12:00 PM. Closed Saturday and Sunday.
- Open since: 2011
- Rating: 4.9 out of 5 stars from 117 Google reviews.
- Services: Brake repair, transmission repair, engine diagnostics, AC and heating repair, cooling system service, steering and suspension, tire service, and scheduled maintenance.
- Vehicles we service: All makes and models, including Toyota, Honda, Ford, Chevrolet, Nissan, Subaru, Lexus, Acura, Hyundai, Kia, Mazda, and Volkswagen.
- Areas we serve: Santa Rosa, Petaluma, Rohnert Park, Sebastopol, Windsor, Healdsburg, Cotati, Sonoma, and Sonoma County.
- Estimates: Free.
- Appointments: Call (707) 326-8655. Same-day service is often available.
Common Questions About Auto Repair in Santa Rosa
Where is On Site Auto Repair located?
We are at 363 W 9th St B & C, Santa Rosa, CA 95401, in the Railroad Square district, just off Highway 101.
Do I need an appointment?
Call (707) 326-8655 first. We often have same-day openings, but calling ahead means we can have the right parts ready.
Do you charge for an estimate?
No. Estimates are free. We tell you the cost before we start any work.
What kinds of cars do you work on?
All makes and models, including Toyota, Honda, Ford, Chevrolet, Nissan, Subaru, Lexus, Acura, Hyundai, Kia, Mazda, and Volkswagen.
Will service here void my new car warranty?
No. We perform warranty-compliant maintenance and repairs. Federal law protects your right to use an independent shop.
Do you offer loaner cars?
No. We are in Railroad Square, with shops, cafes, and public transit in walking distance while you wait.
How long does a brake job take?
Most brake pad and rotor replacements are finished the same day. Call us with your make and model for a closer estimate.
What areas do you serve?
Santa Rosa, Petaluma, Rohnert Park, Sebastopol, Windsor, Healdsburg, Cotati, Sonoma, and the rest of Sonoma County.
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
Latest News
Why Is My Car’s Serpentine Belt Squealing or Cracking in Rohnert Park? What Sonoma County Drivers Need to Know
That squealing noise coming from under your hood in Rohnert Park isn’t something to ignore — it’s often your serpentine belt telling you it’s on borrowed time. Here’s what the belt actually does, how to spot the warning signs, and when to get it replaced before it leaves you stranded.
Why Is My Car’s AC Blowing Warm Air in Petaluma? What’s Really Going On with Your Cooling System
If your car’s AC is blowing warm air in Petaluma or anywhere in Sonoma County, it’s usually one of a handful of fixable problems — not an automatic reason to panic. This guide walks you through the most common causes, what to listen and look for, and when it’s time to bring your vehicle in for a proper diagnosis.
Why Is My Check Engine Light On in Healdsburg? What That Warning Light Is Actually Trying to Tell You
If your check engine light just came on somewhere between Healdsburg and Santa Rosa, don’t panic — but don’t ignore it either. That little amber light can mean anything from a loose gas cap to a misfiring engine, and knowing how to tell the difference can save you from a costly breakdown. Here’s what Sonoma County drivers actually need to know.
Why Is My Car’s Fuel Injector Clogged or Failing in Rohnert Park? What Sonoma County Drivers Need to Know
If your car is running rough, struggling to start, or suddenly getting worse gas mileage, dirty or failing fuel injectors might be the cause. Here’s what Rohnert Park and Sonoma County drivers need to know about fuel injector problems, what they actually feel like to drive, and when it’s time to bring your vehicle in.
Why Is My Car’s Alternator Failing in Sonoma? What Drivers in the Valley Need to Know About Charging System Problems
If your car’s lights are dimming, your battery keeps dying, or you’re hearing a whining noise under the hood, your alternator might be the real culprit. Drivers in Sonoma and throughout Sonoma Valley often confuse alternator problems with battery issues — here’s how to tell the difference and what to do about it.
Why Is My Car’s Differential Making Noise in Cloverdale? What Sonoma County Drivers Need to Know About Differential Service
A whining, grinding, or clunking noise from your differential is easy to ignore — until it becomes a very expensive repair. Here’s what Sonoma County drivers should know about differential service, warning signs, and when to get it checked before it gets worse.
Why Is My Car’s Battery Draining Overnight in Rohnert Park? What a Parasitic Draw Actually Means
If your car is dead every morning in Rohnert Park, the problem might not be the battery itself — it could be a parasitic draw quietly pulling power while your car sits. Here’s what that means, how it’s diagnosed, and when to get it checked by a local mechanic.
Why Is My Car’s Cabin Air Filter Clogged in Sebastopol? What Wildfire Smoke and Dusty Roads Do to Your Interior Air Quality
If your car’s AC feels weak, smells musty, or your windows fog up faster than usual near Sebastopol or the West County, a clogged cabin air filter might be to blame. Here’s what wildfire smoke, dusty rural backroads, and Sonoma County’s seasonal conditions do to your cabin air filter — and when it’s time to replace it.
Why Are My Brakes Fading on the Hills Around Oakmont and Fountaingrove? What Brake Fade Actually Means for Sonoma County Drivers
If your brakes feel soft or less responsive after driving downhill in Oakmont, Fountaingrove, or Bennett Valley, you may be experiencing brake fade — and it’s more serious than most drivers realize. This guide explains what causes brake fade, why hilly Sonoma County terrain makes it more likely, and when to get your brakes inspected before a small issue becomes a dangerous one.
Why Is My Car’s Radiator Failing in Windsor? What Sonoma County Drivers Need to Know About Cooling System Repairs
A failing radiator can turn a normal drive through Windsor or anywhere in Sonoma County into a roadside emergency — especially during hot North Bay summers. Here’s how to spot the warning signs early, what a cooling system repair actually involves, and why catching it now can save you from a much bigger engine bill later.
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.
We Service Clients From All Over Sonoma County
From Wine Country commuters to local families, we provide reliable auto repair services to Santa Rosa, Petaluma, Sebastopol, Rohnert Park, Windsor, Healdsburg, and communities throughout 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.