Question 1

Do you repair raw water pumps for boats?

Lukas · Accepted Answer

Yes. We repair and replace raw water pumps on inboard, sterndrive and outboard engines, whether the problem is a leaking seal, a cracked housing or a failed impeller. We find the cause, give you a written estimate and test the cooling flow after the repair.

Question 2

How do I know if my water pump needs repair?

Lukas · Accepted Answer

Look for symptoms like engine overheating, weak water flow from the exhaust, abnormal engine temperature alarms, or a whining noise near the pump. A failing impeller or blockage is often the cause.

Question 3

Can you replace the impeller on-site?

Lukas · Accepted Answer

Often, yes. Engine-mounted raw water pumps on inboards, and many outboards with the motor tilted up, can be done at your slip. On sterndrives with the pump inside the drive, such as the MerCruiser Alpha, the drive has to come off, so the boat must be out of the water. When we know the engine model, we bring the right impeller kit to the visit.

Question 4

How much does it cost to repair or replace a marine water pump?

Lukas · Accepted Answer

Labor is $150 an hour plus parts and a trip fee per visit by distance, from $30 in San Pedro to $110 in Newport Beach. An impeller or pump replacement usually takes 1-2 hours; pumps that are hard to reach or inside a sterndrive take longer. You get a written estimate before any work starts.

Question 5

Do you service both seawater and freshwater cooling systems?

Lukas · Accepted Answer

Yes, we service both raw water (seawater) and closed-loop freshwater cooling systems. We inspect heat exchangers, replace water pumps, clean strainers, and flush lines for proper flow and cooling.

Question 6

Can a bad water pump damage my marine engine?

Lukas · Accepted Answer

Definitely. A faulty pump can lead to severe overheating, warped heads, or engine failure. That’s why we recommend annual impeller checks and pump inspections – especially before the season starts.

Question 7

Do you offer a warranty on water pump repairs?

Lukas · Accepted Answer

Yes. Our workmanship is warranted for 90 days from the invoice date; new pumps and impellers carry their manufacturer's warranty. Your invoice lists the work and the parts, so you can keep it with your engine records.

Question 8

What are the signs of a worn impeller, a bad thermostat or a failing circulation pump?

Fryderyk Florczak · Accepted Answer

Watch for overheating, especially at idle, a weak stream of water at the exhaust or telltale, swinging temperature readings or alarms. A worn impeller or scored pump housing moves too little water at low rpm; a stuck thermostat makes the engine run hot (stuck closed) or never warm up (stuck open); a failing circulation pump may leak at the weep hole or make bearing noise.

Question 9

Can you test the circulation pump and thermostat without replacing parts right away?

Fryderyk Florczak · Accepted Answer

Yes. We perform full diagnostic testing before recommending replacement. This includes temperature verification, flow testing, thermostat opening temperature checks, and inspection for leaks or internal wear. Only faulty components are replaced, helping you avoid unnecessary costs.

Question 10

What happens if I keep running the engine with a bad thermostat or pump?

Fryderyk Florczak · Accepted Answer

Continuing to operate the engine can lead to severe overheating, warped cylinder heads, blown head gaskets, or internal engine damage. Early testing and repair of the circulation pump or thermostat can prevent major and expensive engine failures.

Question 11

Do you test both raw water and closed-loop cooling systems?

Fryderyk Florczak · Accepted Answer

Yes. We service both raw water–cooled and closed-loop (freshwater) cooling systems. We verify proper coolant circulation, thermostat operation, hose condition, and overall cooling efficiency based on your engine type and manufacturer specifications.

Question 12

How long does an impeller and thermostat service take?

Fryderyk Florczak · Accepted Answer

An impeller and thermostat service usually takes 2-4 hours of labor, depending on engine access. On sterndrives with the pump inside the drive, the drive has to come off, so the boat must be out of the water. Labor is $150 an hour plus the trip fee for work at your boat, and you get a written estimate before any work starts.

Question 13

Do you replace marine thermostats and circulation pumps if needed?

Fryderyk Florczak · Accepted Answer

Yes. We replace marine-grade thermostats and circulation pumps using OEM or high-quality equivalent parts. All installations follow manufacturer torque and sealing specifications to ensure proper cooling system performance and long service life.

Question 14

How often should the raw water impeller be replaced?

Fryderyk Florczak · Accepted Answer

We recommend a new impeller once a year or every 100 hours, whichever comes first, even if the boat sat unused. The rubber vanes take a set and crack with age, and broken pieces can block the heat exchanger.

Question 15

What is a raw water impeller and why is it critical for my engine?

Fryderyk Florczak · Accepted Answer

The raw water impeller is a rubber rotor inside the seawater pump that pulls cooling water from the ocean or lake into your engine. If it fails, the engine can overheat within minutes, leading to serious damage such as warped heads or exhaust system failure. Regular impeller replacement is essential for engine reliability.

Question 16

How often should the raw water impeller be replaced?

Fryderyk Florczak · Accepted Answer

Follow your engine maker's schedule; many call for a new impeller every year or two, and sooner in warm salt water. In Southern California we suggest checking it every year, even if the engine has not overheated.

Question 17

What are the warning signs of a failing impeller?

Fryderyk Florczak · Accepted Answer

Common symptoms include reduced water flow from the exhaust, rising engine temperature, overheating alarms, steam, or a burnt rubber smell. In some cases, an impeller can fail without obvious warning, which is why preventive replacement is strongly recommended.

Question 18

Do you inspect anything else during an impeller replacement?

Fryderyk Florczak · Accepted Answer

Yes. During the service we inspect the pump housing, wear plate, seals, and cam for damage. We also check for broken impeller vanes in the cooling system, which can block heat exchangers and cause overheating later if not removed.

Question 19

Can a broken impeller damage other engine components?

Fryderyk Florczak · Accepted Answer

Absolutely. If impeller blades break off, they can clog oil coolers, heat exchangers, or engine passages. This often leads to chronic overheating and expensive repairs. Proper inspection and debris removal during replacement is critical to avoid future failures.

Question 20

Do you replace impellers dockside or does the boat need to be hauled out?

Fryderyk Florczak · Accepted Answer

An engine-mounted raw water pump is serviced at the slip. On outboards and sterndrives whose pump sits in the lower unit, the drive comes off, so the boat has to be out of the water: on its trailer, in a storage yard or after a haul-out. Each visit to your boat has a trip fee by distance.

Boat Water Pump Repair

Boat Water Pump Repair in Long Beach and San Pedro

What the work covers

Signs of a cooling problem

Questions about boat water pumps

How often should the impeller be replaced?

Can the pump be fixed with the boat in the water?