Welcome to On Site Auto Repair!
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- Real Results: View photos of our team in action.
- Quality Work: See the repairs that earned us 5-star reviews.
- Customer Trust: Trusted across Santa Rosa and Sonoma County.
Serving Santa Rosa Since 2011
★★★★★ 4.9/5 (117 Google Reviews)
Auto 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 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.
Why Is My Car’s Power Steering So Stiff or Noisy in Petaluma? What’s Really Going On
If your steering wheel suddenly feels heavy, makes a whining noise, or jerks when you turn, something’s wrong with your power steering system. Here’s what Petaluma and Sonoma County drivers need to know about the warning signs, what causes them, and when to get it looked at before a small problem becomes a dangerous one.
Why Is My Car’s Timing Belt or Chain Failing in Healdsburg? What Sonoma County Drivers Need to Know
A failing timing belt or chain is one of the most serious — and most overlooked — problems a car can develop. If you’re driving through Healdsburg, Windsor, or anywhere in Sonoma County, here’s how to spot the warning signs before a small issue becomes a catastrophic engine failure.
Why Is My Transmission Slipping or Hesitating in Sonoma? What Automatic Transmission Problems Actually Feel Like
If your car is hesitating between gears, revving high without accelerating, or lurching unexpectedly on Sonoma Valley roads, your automatic transmission may be trying to tell you something important. Here’s how to recognize transmission trouble early — before a manageable repair turns into a costly replacement.
Why Is My Car Pulling to One Side on Highway 101 Near Cotati? What Uneven Tire Wear and Alignment Problems Actually Mean
If your car drifts or pulls to one side while driving Highway 101 near Cotati or anywhere in Sonoma County, it’s not something to brush off. Alignment issues and uneven tire wear often go hand-in-hand, and catching them early can save you hundreds in tire replacements and prevent a dangerous blowout. Here’s what’s really going on under your vehicle.
Why Is My Car Burning Oil So Fast in Healdsburg? What Excessive Oil Consumption Really Means
If you’re adding a quart of oil every few weeks in Healdsburg or anywhere in Sonoma County, something’s not right — and ignoring it can lead to serious engine damage. Here’s how to tell whether you have a real problem, what causes excessive oil consumption, and when it’s time to get your car looked at by a mechanic you can trust.
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.


















