Overheating, low coolant, or a gauge that climbs at every red light. We pressure test the system and find the actual cause instead of topping it off.
Haines City
The technician found a thermostat stuck open, which was the main concern behind the check engine light.
Read the full jobHaines City
After an initial assessment and testing at our Haines City shop, the technician found a water outlet failure.
Read the full jobFrostproof
The technician installed a new coolant temperature sensor and let the owner know the gauge may read differently than it did when the vehicle came in, since…
Read the full jobHaines City
The technician replaced the thermostat housing along with the coolant temperature sensor, with the check engine light as the starting point for the concern.
Read the full jobHaines City
The technician replaced the trans oil cooler line, which was the repair tied to the reported leak at the transmission connector.
Read the full jobSebring
The technician began with a no-charge initial assessment of the overheating concern.
Read the full jobA cooling system has one job: move heat out of the engine faster than the engine makes it. In Central Florida, the hardest part of that job isn't the highway. It's sitting still. At speed, air moves through the radiator on its own. In stop-and-go traffic on a 95 degree afternoon, with the AC compressor adding its own load, the system is leaning entirely on the fans and on coolant that's already close to its working limit. That's why a lot of cars here run fine on the interstate and creep up the gauge waiting at a light.
The system is a loop, and the parts in it fail independently. Coolant carries the heat. The water pump moves it. The thermostat decides when it circulates. Hoses and the radiator cap hold pressure so the coolant can get hotter without boiling. The radiator and the fans dump the heat into the air. Any one of those failing looks about the same from the driver's seat, which is why guessing gets expensive fast.
So we test instead of guessing. A cold pressure test holds the system at operating pressure long enough for a seep to show itself, which beats topping off the reservoir and sending you out the door. We watch the thermostat as the engine comes up to temperature, verify both fan speeds, check what the cap is actually holding, and squeeze every hose. Whatever we find gets photographed and sent to your phone, so you're looking at the same stain or split we are before you decide anything.
This page is the starting point, not the whole story. When the problem turns out to be the radiator core or the water pump specifically, those repairs have their own pages and their own decisions to make. What happens here is figuring out which part of the loop is actually the problem, so you only pay to fix that one.
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4.8 (2,062) as of Oct 20264.8 out of 5, from 2,062 Google reviews, as of October 2026
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Mon to Fri, 7:30 AM to 5:30 PM
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Our experts diagnose and resolve any issue.
Usually a cooling fan that isn't coming on when it should, or a system low enough on coolant that it can't move heat efficiently. Highway airflow covers for both problems, which is why the gauge behaves until you stop.
Small leaks often evaporate off a hot engine before they ever reach the driveway. A pressure test holds the system under load long enough to show where it's escaping.
That's coolant landing on something hot. Common sources are a seeping hose connection, the radiator cap, or the heater core, and each one gets confirmed a different way.
Often a low coolant level or a thermostat stuck open, so the engine never reaches the temperature the heater depends on. It's an early warning that costs nothing to check.
That's a pressure problem. A cap that won't hold, a thermostat stuck closed, or combustion gases getting into the coolant will all do it, and they get tested separately.
Shut it down and call. Continuing to drive an overheating engine turns a hose or thermostat repair into a head gasket repair, and that is a very different bill.
I work out of town and had a cracked radiator. Johnnys automotive not only got me a new radiator but also made sure I could get to the jobsite. Top notch service would recommend to anyone
Phillip Sierputowski
Verified Google Review
Again Johnny's rewarded my trust in them. The car had developed a coolant leak, it was manageable but getting worse and would eventually totally fail at the worst possible time. They were able to get me in the afternoon I called and got a loaner. Next day I had my car back fixed. They have always worked with my weird schedule, and the work has always been excellent.
Jeff Davisson
Verified Google Review
You honestly pay for the awesome quality of service they provide (mechanical & customer service)!!! I came in for an AC issue and after a week, no complaints or problems thus far! I also appreciated the through inspection they did on my little Chevy; I’m truly thankful to them for helping me get my car back on track :)
Victoria IX
Verified Google Review
Thank you for being gracious and for communicating so well. I felt confident leaving my vehicle with you guys while you worked out the AC issue. You guys are First Class!
Jason Parsons
Verified Google Review
If there was a 10* rating, Johnny's Automotive in Lake Wales would receive it‼️I came there for second opinion on a$1500 quote from other independent people for replacing oil cooler,after diagnostic check ‼️It was not oil cooler but only leaking hoses, Johnny's Automotive was honest ,which means a lot 🙏They had me in& out in a couple hours,I was a walk in at 7:30 a.m. I was crying tears of absolute joy& relief when I was called with news,BUT they charged me nothing & I received two long stemed red roses 🌹🌹 when I picked up my car 🙏🙏 Several friends of mine Will not be going back to other repair business,it will be Johnny's Automotive who saved me $1500 🙏🙏
Barbara Goehring
Verified Google Review
So so I had a company truck go down yesterday morning due to a radiator leaking when I got out into the hotel parking lot. I called around to multiple other shops/dealerships and they told me it would be 2 to 3 days before they could even look at the truck. I called Johnny’s and told them my situation and that it’s a work vehicle and when is down the company doesn’t make money they got me in that morning. Had a diagnosed and fixed in the same day. I would recommend this shop to anyone in the area of Sebring or surrounding their customer. Service was great and took well care of me thank you to all of the employees that helped me get my vehicle back on the road. If I’m in the area I’m definitely bringing my work trucks here. I’ll
Josuha Rushing (TMSTANCE_903)
Verified Google Review
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Oct 2, 2026 · 7 min read
September in review: we completed 1,181 repair orders across our six Central Florida shops, led by diagnostics and oil changes. Here's what came through, what it says about the season, and what to watch next.
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A driver's tour of every belt and hose under the hood, why Central Florida heat ages rubber faster than mileage does, and the five-minute check you can do cold.
Read articleCommon questions about our cooling system repair.
You can get home that way. But coolant doesn't get used up the way oil does, so if the level dropped, it went somewhere. Topping off without finding the leak means you'll be doing it again, usually at a worse time and in a worse place.
It can. The AC condenser sits right in front of the radiator and adds heat exactly where the radiator is trying to shed it, and the compressor puts extra load on the engine. If your car only runs hot with the AC on in traffic, that's a real clue, and the fans are the first thing we test.
Sometimes, if the coolant is old and contaminated and heat transfer has fallen off. More often overheating is a failed part, and a flush just delays finding it. We'd rather test first and tell you which situation you're in.
It depends on the manufacturer, and the types aren't interchangeable. Mixing them can cause gelling and corrosion inside the system. We look up the specification for your vehicle rather than pouring in whatever says universal on the jug.
There's a test for it. We check the coolant for combustion gases and watch how the system behaves under pressure. That gives a specific answer rather than a guess, and we'd rather rule it out early than have you find it after paying for other parts.
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