Our Services 1 Welcome to On Site Auto Repair!

Our Services

Complete Auto Repair Services — Done Right the First Time

From brake and transmission repair to diagnostics and routine maintenance, our certified mechanics handle all makes and models with precision, honesty, and fast turnaround.

Serving Santa Rosa Since 2011

★★★★★ 4.8/5 (100+ Reviews)

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Complete 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.

Brakes Services in Santa Rosa

Brake Services

  • Brake pads, rotors, fluid replacement
  • “Starting at $89”

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Transmission in Santa Rosa

Transmission Repair

  • Automatic & manual transmission service
  • “Free diagnostic”

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Cooling Systems in Santa Rosa

Engine Repair & Diagnostics

  • Automatic & manual transmission service
  • “Free diagnostic”

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Heating & Ac in Santa Rosa

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Heating & AC Service

  • Climate control repair, refrigerant service
  • “Stay comfortable year-round”
Steering & Suspension in Santa Rosa

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Steering & Suspension

  • Shocks, struts, alignment service
  • “Smooth, safe driving”
Tires Service in Santa Rosa

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Cooling System Service

  • Radiator repair, coolant flush
  • “Prevent overheating”
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What Our Clients Say

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Our Services 2  Brands We Service

Auto Repair Brand

Toyota Auto Repair Santa Rosa

Toyota Repair

Honda Auto Repair Santa Rosa

Honda Repair

Ford Auto Repair Santa Rosa

Ford Repair

chevrolet Auto Repair Santa Rosa

Chevrolet Repair

Nissan Auto Repair Santa Rosa

Nissan Repair

Mercedes Auto Repair Santa Rosa

Mercedes Repair

Lexus Auto Repair Santa Rosa

Lexus Repair

Acura  Auto Repair Santa Rosa

Acura Repair

Infiniti Auto Repair Santa Rosa

Infiniti Repair

Kia Auto Repair Santa Rosa

Kia Repair

Hyundai Auto Repair Santa Rosa

Hyundai Repair

Subaru Auto Repair Santa Rosa

Subaru Repair

Mazda Auto Repair Santa Rosa

Mazda Repair

Volkswagen Auto Repair Santa Rosa

Volkswagen Repair

Contact Info

Location

363 W 9th St B & C
Santa Rosa, CA 95401

Phone

707-326-8655

Hours

  • Monday-Friday: 8:00 AM - 5:30 PM
  • Saturday: 8:00 AM - 4:00 PM
  • Sunday: Closed

New Customer Special:

$25 Off First Service Over $100

Oil Change Special:

Full Synthetic Oil Change – $69.9

Free Brake Inspection

Complete brake system check at no charge

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Our Blog

Latest News

Why Is My Car Hesitating When I Accelerate in Santa Rosa? What’s Causing That Sluggish Response

Why Is My Car Hesitating When I Accelerate in Santa Rosa? What’s Causing That Sluggish Response

If your car hesitates, stumbles, or feels sluggish when you press the gas pedal in Santa Rosa or anywhere in Sonoma County, something is off — and it’s usually more than just a minor annoyance. This article explains the most common causes of acceleration hesitation, what warning signs to watch for, and when it’s time to bring your vehicle in before a small problem turns into a costly repair.

Why Is My Car Making a Grinding Noise When I Turn in Petaluma? What’s Going On with Your CV Axles and Wheel Bearings

Why Is My Car Making a Grinding Noise When I Turn in Petaluma? What’s Going On with Your CV Axles and Wheel Bearings

A grinding or clicking noise when you turn your steering wheel is one of those symptoms you shouldn’t ignore — it usually means your CV axles or wheel bearings are telling you something important. If you’re driving around Petaluma or anywhere in Sonoma County and noticing this sound, here’s what it actually means and when to get it checked.

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Our Services

Read More About Our Auto Mechanic Services

Auto Repair In Santa Rosa

On Site Auto Repair in Santa Rosa is a full service auto mechanic shop. Our auto mechanics are certified and here to help you with all of your automotive repair needs. No auto repair job is too big or too small for On Site Auto Repair.We specialize in all types of auto repair, including: regular maintenance, break/fix, engine repair, troubleshooting and much more! If you are looking for honest and reliable auto mechanics, give us a call today. Ask us about our new customer specials

Transmission Repair In Santa Rosa

Vehicles are usually described as 5 or 6 “speed” meaning then have that many gear ratios to allow the vehicle to travel at the full range of speeds required and to make use of the engine’s output power as efficiently as possible. Due to their complexity, constant use and function within a vehicle’s operation, transmissions experience a lot of wear and tear. Add to this the fact that many owner’s forget to check and change the fluid on a regular basis and it’s easy to understand why so many people have transmission problems. At On Site Auto Repair in Santa Rosa, our transmission repair technicians can accurately diagnose, repair or replace your transmission. If your are looking for a reliable and honest transmission repair services company, give us a call today!

Transmission Repair In Santa Rosa
Brake Service In Santa Rosa

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

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.

Vehicle Inspection In Santa Rosa
Radiator Inspection Service In Santa Rosa

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.

SANTA ROSA WEATHER
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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.

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Auto Mechanic Services We Offer in Sonoma, CA

We handle a wide range of repairs and maintenance, all performed at your location. Here's what we do most often for drivers in Sonoma and nearby areas like Glen Ellen, El Verano, Kenwood, Petaluma, and Santa Rosa.

Engine Diagnostics and Check Engine Light

That check engine light makes most people nervous — and honestly, it should. It's your car telling you something's off. We plug in an OBD-II scanner, pull the fault codes, and actually explain what they mean in plain English. No guesswork, no upselling you on repairs you don't need.

We diagnose the problem first, then give you a straight answer about what it will take to fix it.

Oil Change Service

We do full-synthetic and conventional oil changes at your home or workplace. We use the correct viscosity grade for your vehicle — 5W-30, 5W-20, 0W-20, or whatever your manufacturer specifies — and we replace the oil filter every time.

Honest truth: most people wait too long between oil changes. It's the cheapest maintenance you can do to extend the life of your engine. We make it easier by bringing it to you.

Brake Repair and Replacement

Worn brake pads squeak. Worn rotors grind. Soft pedals are a warning you shouldn't ignore. We inspect and replace brake pads, rotors, and calipers using both OEM-quality and aftermarket parts, depending on your preference and budget.

If you're hearing anything unusual from your brakes, don't wait. Brake jobs that get delayed usually end up costing more.

Battery Replacement and Testing

Dead batteries don't give much warning. We test your battery with a proper load tester — not just a voltage check — and if it's on its way out, we replace it with an AGM or standard lead-acid battery sized for your vehicle. We also check the alternator and charging system while we're at it, since a bad alternator kills new batteries fast.

Alternator and Starter Repair

If your car won't start or your battery keeps dying, the problem is often the alternator or starter. We test both, figure out which one is the culprit, and fix it on-site. This is exactly the kind of repair people think requires a shop — it usually doesn't.

AC and Heating Repair

Sonoma summers get warm. If your AC isn't blowing cold, we can recharge the refrigerant and check for leaks. If your heat isn't working in the colder months, we'll diagnose the issue and get it sorted. Comfort on the road matters, and we don't treat climate control as a low-priority service.

Scheduled Maintenance and Tune-Ups

Staying on top of scheduled maintenance is the single best way to avoid expensive repairs down the road. We handle:

  • Spark plug replacement (iridium and platinum)
  • Timing belt and serpentine belt inspection and replacement
  • Air and cabin filter replacement
  • Fuel system service and fuel injector cleaning
  • Coolant system flush (HOAT and OAT compatible formulas)
  • Transmission fluid flush and filter service

If you're not sure what your car is due for, we'll check your maintenance records or look it up by your vehicle's make, model, and mileage. We won't pad the list.

Tire Rotation and Inspection

Uneven tire wear is more than an aesthetics problem. It affects handling, fuel economy, and how long your tires last. We rotate your tires, check tread depth, inspect sidewalls, and check pressure. Simple service, done where you are.

Pre-Purchase Inspection

Thinking about buying a used car? Get it inspected before you commit. We'll look at what matters: brakes, belts, fluid conditions, undercarriage rust, suspension, and run a diagnostic scan for hidden fault codes. A $100-150 inspection can save you thousands on a bad purchase. We serve buyers all across the Sonoma Valley and into Napa County.

Roadside Assistance and Emergency Repairs

Stuck in Kenwood? Broken down near El Verano or out on Highway 12? If it's something we can fix on the spot, we will. Give us a call and we'll tell you honestly whether we can help or whether you need a tow.

Why Sonoma Drivers Choose On-Site Auto Repair

Most auto shops in and around Sonoma, CA do good work. The problem isn't the quality — it's the hassle. Drop the car off, wait for a call, figure out a ride home, go back and pick it up. That cycle eats your whole day.

We skip all of that.

Here's what you actually get when you book with us:

No tow truck needed. If your car starts (or even if it doesn't and you're local), we come to you. No dragging your car across town.

Flat-rate, upfront pricing. You know what it costs before we touch anything. No surprises when you get the bill.

Same-day appointments available. We know car problems don't schedule themselves. We do our best to get to you fast.

ASE Certified mechanic. Not a weekend hobbyist. A credentialed professional with real diagnostic tools.

California BAR Licensed. We're registered with the Bureau of Automotive Repair, which means we follow the rules and you have legal protections if something goes wrong. Most customers don't know to ask about this, but it matters.

Parts and labor warranty. Every repair is backed by a 12-month / 12,000-mile warranty. We stand behind our work.

We've been serving Sonoma, CA and the surrounding Sonoma County communities for years. Our Google reviews tell the story better than we can.

Ready to Book? Here's How It Works

Call or message us with your vehicle, location, and what's going on with your car.

Get a free estimate before we schedule anything.

Pick a time that works for you — at your home, office, or wherever the car is.

We show up, fix it, and you pay after the job is done.

That's it. No waiting rooms. No borrowed rides. No surprises on the bill.

On-Site Auto Repair — Sonoma, CA Serving Sonoma Valley, Glen Ellen, El Verano, Kenwood, Petaluma, Santa Rosa, and surrounding Sonoma County.

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.

Call (707) 326-8655 now or stop by our shop at 363 W 9th St B & C in Santa Rosa’s Railroad Square district.

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