This page lists 3 cooling system parts for the 2019 Mazda 3, across 1 part type, covering the 2.5L L4 engine. Every part shows its brand, manufacturer part number and fitment notes.
On the 2019 Mazda 3, the cooling system system keeps operating temperature in the narrow band the engine was designed for, from radiator and water pump to thermostat and hoses. Every listed part is Coolant Hose / Pipe Seal.
Every part on this page is matched to the 2.5L L4 — the only engine offered in the 2019 Mazda 3.
The most listed brands for 2019 Mazda 3 cooling system parts are MAHLE / CLEVITE (2 parts) and AJUSA (1 part).
Each part number listed for the 2019 Mazda 3 opens a page with every vehicle that part fits.
Coolant Hose / Pipe Seal
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| AJUSA | 16564000 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | COOLANT PIPE | View on Amazon |
| MAHLE / CLEVITE | C33805 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Engine Coolant Outlet O-RingMolded Rubber | View on Amazon |
| MAHLE / CLEVITE | C33644 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Engine Coolant Outlet O-RingMolded Rubber | View on Amazon |
This table covers the seals at the Coolant Hose / Pipe. Typical signs include a wet housing, a drip after sitting, or fluid flung off a rotating shaft. Fix the surface the seal rides on. A new seal on a grooved shaft will leak again.
3 Coolant Hose / Pipe Seal parts are listed for the 2019 Mazda 3, from MAHLE / CLEVITE and AJUSA.
Part numbers include AJUSA 16564000, MAHLE / CLEVITE C33805 and MAHLE / CLEVITE C33644.
Buying Cooling System Parts for a 2019 Mazda 3
On this vehicle, the cooling system system keeps operating temperature in the narrow band the engine was designed for, from radiator and water pump to thermostat and hoses.
- Confirm you have the 2.5L L4 engine — every part on this page is matched to it.
- Read the notes on each row for position, trim and spec qualifiers before you order.
- Where labor overlaps, replace the thermostat and refill with fresh coolant whenever you change a water pump or radiator; original hoses on an older vehicle are on borrowed time.
- Cross-reference the manufacturer part number against your old part or a service-manual listing.
Start with the largest groups on this page: Coolant Hose / Pipe Seal .
Frequently Asked Questions
How many cooling system parts fit the 2019 Mazda 3?
Our catalog currently lists 3 cooling system parts for the 2019 Mazda 3 across 1 subcategory and 2 brands, covering the 2.5L L4 engine. Each part is matched to the engine(s) it fits.
What are the signs of cooling system problems on a 2019 Mazda 3?
Common symptoms include a rising temperature gauge in traffic, sweet-smelling steam, crusty deposits around hose clamps, or a heater that blows cold. If you notice any of these, identify the affected subcategory above and cross-reference the part numbers listed.
What should I replace at the same time?
Where labor overlaps, replace the thermostat and refill with fresh coolant whenever you change a water pump or radiator; original hoses on an older vehicle are on borrowed time.
What do the market flags (US, CA, MX) on each part mean?
They show the market for which the manufacturer published application data for that part — where the vehicle was first sold, not where the part was made. If your 2019 Mazda 3 was originally sold in the US, the safest choice is a part marked for the US market.
How do I make sure a part fits my 2019 Mazda 3?
Every part on this page is matched to the 2.5L L4 engine. Then replace coolant with the exact specification the manufacturer calls for — mixing chemistries can gel and block small passages. The notes column carries position and trim qualifiers where they apply.
Other Parts for the 2019 Mazda 3
Cooling System Parts for Other Mazda 3 Years
Switch vehicle or jump to a subcategory
Manufacturer names, model designations and part numbers are used for identification and fitment reference only. AutoFactsDB is an independent catalog and is not affiliated with, endorsed by, or sponsored by any vehicle manufacturer displayed on this page.