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Thermostats & Cooling Components - Marine Engine Parts

Marine Thermostats & Cooling Components

Marine Thermostats, Pumps, Impellers, Heat Exchangers, Hoses & Cooling Parts

Shop marine cooling system parts for inboard, sterndrive, outboard, gas, and diesel engines. Find thermostats, thermostat housings, raw-water pumps, circulation pumps, impellers, heat exchangers, oil coolers, strainers, coolant caps, hoses, clamps, gaskets, seals, temperature senders, and cooling service parts.

Fitment Check

Match cooling parts by engine brand, model, serial number, existing part number, cooling layout, hose size, thermostat temperature, and pump style.

Ask Parts Desk

Overheating can come from more than one part. Check the full cooling path before assuming a thermostat, pump, impeller, hose, strainer, or heat exchanger is the only issue.

Find Cooling Parts Faster

Search by Part Number, Engine Model, Temperature, Hose Size, or Cooling Symptom

Use the search box for thermostats, thermostat housings, raw-water pumps, circulation pumps, impellers, coolers, hoses, clamps, strainers, caps, seals, senders, and cooling kits.

Raw-Water Side

Seawater Flow Protects the Engine and Exhaust

Raw-water systems depend on a clean intake path, healthy impeller, strong pump, good hoses, clear strainers, clean coolers, and proper exhaust water flow. Weak seawater flow can cause overheating quickly.

Closed Cooling

Thermostats, Coolant, and Heat Exchangers Control Temperature

Closed-cooling systems depend on the right coolant, thermostat, circulation pump, pressure cap, heat exchanger, hoses, seals, and clean passages to keep engine temperature stable.

TEMP

Control Temperature

Thermostats, senders, pumps, coolant, caps, and heat exchangers all affect stable operating temperature.

FLOW

Protect Water Flow

Impellers, strainers, hoses, clamps, pump covers, and coolers should be inspected when flow seems weak.

SEAL

Replace Seals Carefully

Use the correct gaskets, O-rings, washers, caps, and clamps when cooling parts are opened.

Cooling Service Help

Overheating Usually Deserves a Full-System Look

Replacing one part may not solve a cooling issue if the root cause is a clogged strainer, worn impeller, failing thermostat, soft hose, leaking cap, weak pump, blocked heat exchanger, air leak, or exhaust restriction.

Inspect seawater flowCheck seacock, strainer, hoses, impeller, pump cover, cam, wear plate, and discharge flow.
Check closed coolingConfirm coolant condition, coolant level, pressure cap, thermostat, circulation pump, and heat exchanger condition.
Watch for corrosionSalt trails, pitting, green deposits, clogged passages, and leaking end caps are warning signs.

Cooling Components FAQ

Choosing Marine Thermostats and Cooling Parts

How do I find the right marine thermostat?

Start with the engine brand, model, serial number, current thermostat part number, thermostat temperature rating, and housing style. Similar thermostats may not fit or operate correctly.

What causes a marine engine to overheat?

Common causes include worn impellers, clogged strainers, blocked heat exchangers, failing thermostats, soft hoses, weak pumps, low coolant, exhaust restrictions, or air leaks on the intake side.

Should gaskets and O-rings be replaced during cooling service?

Yes. When opening cooling components, use the correct replacement gaskets, O-rings, washers, seals, and clamps for the part and engine model.

Can the Parts Desk help identify cooling parts?

Yes. Send the engine brand, model, serial number, photos of the part, hose diameter, old part numbers, and the symptom you are trying to solve.

Shop Marine Thermostats, Pumps, Impellers, Heat Exchangers, Hoses & Cooling Parts

Find the cooling components and service parts needed to keep marine engines flowing properly and running at the right temperature.

Filters

Volvo Penta Thermostat Kit – 3831424

Original price $86.00 - Original price $86.00
Original price
$86.00
$86.00 - $86.00
Current price $86.00
Only 2 left!

The Volvo Penta 3831424 Thermostat Kit is a genuine OEM cooling system service kit engineered to deliver precise thermal regulation and long-term r...

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Original price $86.00 - Original price $86.00
Original price
$86.00
$86.00 - $86.00
Current price $86.00

Volvo Penta Thermostat 3587597

Original price $42.40 - Original price $42.40
Original price
$42.40
$42.40 - $42.40
Current price $42.40
Only 1 left!

The Volvo Penta 3587597 Thermostat is a genuine OEM cooling system component engineered to provide precise thermal regulation in Volvo Penta gasoli...

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Original price $42.40 - Original price $42.40
Original price
$42.40
$42.40 - $42.40
Current price $42.40

Volvo Penta Thermostat 3583827

Original price $212.00 - Original price $212.00
Original price
$212.00
$212.00 - $212.00
Current price $212.00
Out of stock

Volvo Penta Thermostat — Part No. 3583827 OEM replacement thermostat element for Volvo Penta D4 and D6 diesel marine engines. This thermostat regul...

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Original price $212.00 - Original price $212.00
Original price
$212.00
$212.00 - $212.00
Current price $212.00
Sold out

Volvo Penta Thermostat – 21437904

Original price $99.00 - Original price $99.00
Original price
$99.00
$99.00 - $99.00
Current price $99.00
Only 2 left!

The Volvo Penta 21437904 Thermostat is a genuine OEM cooling system component engineered for precise temperature regulation in Volvo Penta marine e...

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Original price $99.00 - Original price $99.00
Original price
$99.00
$99.00 - $99.00
Current price $99.00

Volvo Penta Thermostat 82°C 20450736 | D5A D7A D7C TAD Series

Original price $150.00 - Original price $150.00
Original price
$150.00
$150.00 - $150.00
Current price $150.00
Only 1 left!

Volvo Penta OEM Thermostat — Part No. 20450736 Part Number: 20450736 Brand: Volvo Penta (Genuine OEM) Type: Engine Cooling Thermostat Opening...

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Original price $150.00 - Original price $150.00
Original price
$150.00
$150.00 - $150.00
Current price $150.00

PCM Thermostat Housing Gasket RM0001

Original price $1.78 - Original price $1.78
Original price
$1.78
$1.78 - $1.78
Current price $1.78
Only 1 left!

Seal the thermostat housing and maintain proper engine cooling with the PCM Thermostat Housing Gasket RM0001. This genuine Pleasurecraft Marine (PC...

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Original price $1.78 - Original price $1.78
Original price
$1.78
$1.78 - $1.78
Current price $1.78

MerCruiser Thermostat – 991551

Original price $62.69 - Original price $62.69
Original price
$62.69
$62.69 - $62.69
Current price $62.69
Only 2 left!

The Mercury MerCruiser 991551 Thermostat is a genuine OEM 160°F (71°C) thermostat designed for GM-based MerCruiser marine engines equipped with clo...

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Original price $62.69 - Original price $62.69
Original price
$62.69
$62.69 - $62.69
Current price $62.69

Mercury Outboard Thermostat 140°F – 8M0162139

Original price $198.83 - Original price $198.83
Original price
$198.83
$198.83 - $198.83
Current price $198.83
Only 3 left!

The Mercury / Quicksilver 8M0162139 Thermostat is a genuine OEM 140°F (60°C) thermostat designed for modern Mercury outboard engines. This thermost...

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Original price $198.83 - Original price $198.83
Original price
$198.83
$198.83 - $198.83
Current price $198.83

Mercury Outboard 140°F Thermostat - 8M0119207

Original price $127.27 - Original price $127.27
Original price
$127.27
$127.27 - $127.27
Current price $127.27
Only 1 left!

The Mercury Quicksilver 8M0119207 is a genuine Mercury Marine OEM 140°F / 60°C thermostat used in select Mercury, Mariner, and SeaPro outboard cool...

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Original price $127.27 - Original price $127.27
Original price
$127.27
$127.27 - $127.27
Current price $127.27

Mercury Outboard Thermostat 120°F – 8M0117413

Original price $40.95 - Original price $40.95
Original price
$40.95
$40.95 - $40.95
Current price $40.95
Only 1 left!

The Mercury / Quicksilver 8M0117413 Thermostat is a genuine OEM 120°F (48.8°C) thermostat used on small-to-mid horsepower Mercury 4-stroke outboard...

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Original price $40.95 - Original price $40.95
Original price
$40.95
$40.95 - $40.95
Current price $40.95

Mercury MerCruiser 160°F Thermostat - 8M0109441

Original price $53.19 - Original price $53.19
Original price
$53.19
$53.19 - $53.19
Current price $53.19
Only 2 left!

The Mercury MerCruiser Quicksilver 8M0109441 is a genuine Mercury Marine OEM 160°F thermostat used in select MerCruiser sterndrive, inboard, and Me...

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Original price $53.19 - Original price $53.19
Original price
$53.19
$53.19 - $53.19
Current price $53.19

Mercury Outboard Thermostat Assembly 120°F – 8M0090819

Original price $144.55 - Original price $144.55
Original price
$144.55
$144.55 - $144.55
Current price $144.55
Only 1 left!

The Mercury / Quicksilver 8M0090819 Thermostat Assembly is a genuine OEM 120°F thermostat with integrated housing, designed for Mercury EFI 4-strok...

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Original price $144.55 - Original price $144.55
Original price
$144.55
$144.55 - $144.55
Current price $144.55

Mercury MerCruiser Thermostat 160°F | 8M0076464 | 496 MAG / 8.1L Big Block

Original price $61.92 - Original price $61.92
Original price
$61.92
$61.92 - $61.92
Current price $61.92
Only 1 left!

Mercury MerCruiser Thermostat 160°F | Part 8M0076464 Part Number: 8M0076464 Brand: Mercury Marine / Quicksilver Official Product Type: Engine Ther...

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Original price $61.92 - Original price $61.92
Original price
$61.92
$61.92 - $61.92
Current price $61.92

MerCruiser Thermostat – 882604

Original price $159.21 - Original price $159.21
Original price
$159.21
$159.21 - $159.21
Current price $159.21
Only 1 left!

he Mercury MerCruiser 882604 Thermostat is a genuine OEM thermostat designed for MerCruiser CMD 1.7L diesel engines (DTI platform). This thermostat...

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Original price $159.21 - Original price $159.21
Original price
$159.21
$159.21 - $159.21
Current price $159.21

Mercury MerCruiser Thermostat – 853213001

Original price $53.15 - Original price $53.15
Original price
$53.15
$53.15 - $53.15
Current price $53.15
Only 1 left!

The Mercury MerCruiser Thermostat 853213001 is a genuine OEM cooling system component designed to regulate engine temperature and maintain optimal ...

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Original price $53.15 - Original price $53.15
Original price
$53.15
$53.15 - $53.15
Current price $53.15

Mercury MerCruiser Thermostat Kit 807252T5

Original price $76.48 - Original price $76.48
Original price $76.48
$76.48
$76.48 - $76.48
Current price $76.48
Only 2 left!

Mercury 807252T5 is a genuine OEM 160°F thermostat kit for selected MerCruiser sterndrive and inboard engines. Mercury’s official listing ident...

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Original price $76.48 - Original price $76.48
Original price $76.48
$76.48
$76.48 - $76.48
Current price $76.48

MerCruiser Thermostat Kit – 807252T4

Original price $99.93 - Original price $99.93
Original price
$99.93
$99.93 - $99.93
Current price $99.93
6 in stock

The Mercury MerCruiser Thermostat Kit 807252T4 is a genuine OEM thermostat service kit designed for GM-based V6 and V8 MerCruiser engines using clo...

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Original price $99.93 - Original price $99.93
Original price
$99.93
$99.93 - $99.93
Current price $99.93

MerCruiser Thermostat Seal – 8071341

Original price $14.84 - Original price $14.84
Original price
$14.84
$14.84 - $14.84
Current price $14.84
Only 2 left!

he Mercury MerCruiser Thermostat Seal 8071341 is a genuine OEM rubber sealing ring designed to properly seal the thermostat within the thermostat h...

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Original price $14.84 - Original price $14.84
Original price
$14.84
$14.84 - $14.84
Current price $14.84

Mercury MerCruiser Quicksilver 160°F Thermostat 76270T

Original price $73.42 - Original price $73.42
Original price
$73.42
$73.42 - $73.42
Current price $73.42
Only 1 left!

160°F Engine Thermostat — OEM Reference 76270T Part Number: 76270T Brand: Mercury Marine / MerCruiser / Quicksilver Official Product Type: Engine ...

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Original price $73.42 - Original price $73.42
Original price
$73.42
$73.42 - $73.42
Current price $73.42

Mercury - Thermostat 120 - 14586

Original price $61.90 - Original price $61.90
Original price
$61.90
$61.90 - $61.90
Current price $61.90
Item locally warehoused

The Mercury Thermostat 14586 is a 120°F thermostat for Mercury 40 HP through 60 HP 4-stroke outboards, serial number 1C050252 and above. It helps r...

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Original price $61.90 - Original price $61.90
Original price
$61.90
$61.90 - $61.90
Current price $61.90

Indmar LY6 Thermostat 160°F Drilled – 986115D

Original price $58.22 - Original price $58.22
Original price
$58.22
$58.22 - $58.22
Current price $58.22
Only 1 left!

The Indmar Thermostat 986115D is a genuine OEM 160°F drilled thermostat designed for GM Gen IV LY6 and L96 marine engines equipped with closed cool...

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Original price $58.22 - Original price $58.22
Original price
$58.22
$58.22 - $58.22
Current price $58.22

Indmar Thermostat Housing Gasket - OEM Engine Cooling Seal

Original price $5.86 - Original price $5.86
Original price
$5.86
$5.86 - $5.86
Current price $5.86
Only 5 left!

Premium OEM thermostat housing gasket engineered for Indmar marine engines. This precision-cut gasket creates a reliable seal between the thermosta...

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Original price $5.86 - Original price $5.86
Original price
$5.86
$5.86 - $5.86
Current price $5.86

Indmar Chevrolet Raw Water Thermostat Housing Gasket - OEM Seal

Original price $5.85 - Original price $5.85
Original price
$5.85
$5.85 - $5.85
Current price $5.85
Only 5 left!

Premium OEM thermostat housing gasket engineered for Indmar Chevrolet marine engines. This precision-cut gasket creates a reliable seal between the...

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Original price $5.85 - Original price $5.85
Original price
$5.85
$5.85 - $5.85
Current price $5.85

Westerbeke Thermostat 77°C (170°F) – 822-0377

Original price $55.20 - Original price $55.20
Original price
$55.20
$55.20 - $55.20
Current price $55.20
Only 2 left!

The Westerbeke Thermostat 822-0377 is a genuine OEM 77°C (170°F) thermostat designed for Westerbeke marine diesel and gasoline engines as well as g...

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Original price $55.20 - Original price $55.20
Original price
$55.20
$55.20 - $55.20
Current price $55.20

Crusader Copper Thermostat Housing | OEM 98202 | Rear-Mounted Heat Exchanger | 7.4L / 454 / 502

Original price $344.89 - Original price $344.89
Original price
$344.89
$344.89 - $344.89
Current price $344.89
Out of stock

Crusader Copper Thermostat Housing — OEM 98202 Part Number: 98202 (Crusader OEM)  |  Brand: Crusader / PleasureCraft Marine Engine Group Genuine Cr...

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Original price $344.89 - Original price $344.89
Original price
$344.89
$344.89 - $344.89
Current price $344.89
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Honeywell Home Digital Thermostat RTH5160D1016 - Marine HVAC Control

Original price $68.87 - Original price $68.87
Original price
$68.87
$68.87 - $68.87
Current price $68.87
Out of stock

Honeywell Home Digital Thermostat - Marine Climate Control Reliable digital thermostat for precise temperature control of your boat's heating and a...

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Original price $68.87 - Original price $68.87
Original price
$68.87
$68.87 - $68.87
Current price $68.87
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Yanmar Thermostat 105582-49200 - Marine Diesel Engine

Original price $65.85 - Original price $65.85
Original price
$65.85
$65.85 - $65.85
Current price $65.85
Only 4 left!

Genuine Yanmar Thermostat - Professional Marine Engine Component OEM thermostat designed for Yanmar marine diesel engines. Precision-engineered tem...

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Original price $65.85 - Original price $65.85
Original price
$65.85
$65.85 - $65.85
Current price $65.85