Your engine oil cooler is vital in regulating oil temperature, ensuring your engine doesn’t overheat and run inefficiently. Replacing a failing oil cooler can seem overwhelming, but with the right knowledge and tools, it can be a straightforward task, even for DIYers.
This guide offers seven essential tips to make your engine oil cooler replacement process smooth, efficient, and cost-effective.
Engine Oil Cooler Replacement
Step-by-Step Replacement Process
1. Prepare the Vehicle
- Disconnect the negative battery terminal to prevent electrical issues.
- Place a drain pan under the radiator and engine to catch any fluids.
- If necessary, jack up the vehicle and secure it with jack stands for better access.
2. Drain the Fluids
- Remove the radiator cap and open the radiator drain plug to empty the coolant into the drain pan.
- Remove the oil drain plug from the oil pan and drain the engine oil. Replace the drain plug once the oil has fully drained.
- Properly dispose of used oil and coolant at a recycling center or auto shop.
3. Locate and Remove the Oil Cooler
- Identify the oil cooler’s location, typically near the radiator or oil filter housing. It may resemble a small radiator or a cylindrical unit with hoses or lines attached.
- Disconnect any hoses, lines, or electrical connectors attached to the oil cooler. Use pliers or a wrench to loosen clamps or fittings, and label connections for easy reassembly.
- Remove the mounting bolts or brackets securing the oil cooler. Keep track of all hardware for reinstallation.
- Carefully remove the oil cooler, noting any gaskets or O-rings that may need replacement.
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4. Install the New Oil Cooler
- Clean the mounting area and mating surfaces with a degreaser and a rag to ensure a proper seal.
- Install new gaskets or O-rings (included with the new oil cooler) to prevent leaks.
- Position the new oil cooler and secure it with the original or new mounting bolts. Tighten to the manufacturer’s torque specifications using a torque wrench.
- Reconnect all hoses, lines, and connectors, ensuring they are snug and properly seated.
5. Refill Fluids and Test
- Replace the oil filter if it’s near the oil cooler or due for a change.
- Refill the engine with the recommended oil type and quantity, checking the dipstick to confirm the level.
- Refill the cooling system with the appropriate coolant mixture, following your vehicle’s specifications.
- Reconnect the battery terminal and start the engine. Let it idle for a few minutes, checking for leaks around the oil cooler and connections.
- Top off fluids as needed after the engine cools, and dispose of any spilled fluids responsibly.
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6. Final Checks
- Take the vehicle for a short test drive to ensure normal operation. Monitor the oil and coolant levels over the next few days.
- Inspect for leaks or unusual noises, and address any issues immediately.
- If the oil cooler is part of the radiator assembly, ensure the cooling system is properly bled to remove air pockets.
Best Universal Engine Oil Cooler
Mishimoto Universal 10‑Row Oil Cooler Kit
- Why it stands out: Core built with durable aluminum, stacked-plate design for minimal pressure loss, and backed by a lifetime warranty
- Specs: 10 rows, -10AN inlet/outlet, includes sandwich plate options, braided stainless hoses.
- Ideal for: Performance engines and track use with reliable long-term performance.
EVIL ENERGY 16‑Row AN10 Stacked‑Plate Cooler Kit
- Why it’s a bargain: 16 rows of cooling surface, included mounting bracket, and AN10 fittings.
- Customer feedback: Users praise value and cooling capacity, but note occasional fitting leaks, better to double-check seals.
- Ideal for: DIYers looking for solid cooling without breaking the bank.
Hayden Automotive 678 Universal Rapid‑Cool
- Why it works: High-quality plate-and-fin cooler, designed for towing and high-load scenarios, with patented internal turbulation for efficient heat transfer and minimal pressure drop
- Specs: 9.5″ × 11″, hose-barb fittings.
- Ideal for: Trucks, vans, and heavy-duty use.
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Tips for Success
- Work Cleanly: Oil and coolant spills can be hazardous and attract dirt. Use rags to keep your workspace tidy.
- Double-Check Connections: Loose fittings can cause leaks, so ensure everything is secure before starting the engine.
- Use OEM Parts: While aftermarket oil coolers are often cheaper, OEM parts typically offer better fit and reliability.
- Consult a Professional: If you’re unsure about any step or lack the tools, consider hiring a mechanic to avoid damaging your vehicle.
FAQs
How much does it cost to replace an engine oil cooler?
The total cost to replace an engine oil cooler typically ranges from $350 to $900, depending on your vehicle make and model, labor rates, and the type of cooler used. Here’s a rough breakdown:
- Parts (OEM or aftermarket cooler): $100 – $300
- Labor (professional service): $200 – $500
- Additional costs (engine oil, coolant, gaskets): $50 – $100
DIY replacement can save you significantly on labor but requires mechanical skill and tools.
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Can I drive with a bad oil cooler?
It is not recommended. Driving with a bad oil cooler can lead to engine overheating, oil contamination, or even engine failure. A damaged oil cooler might leak oil or coolant, causing:
- Sudden drops in oil pressure
- Poor lubrication
- Serious internal engine damage
If you notice any symptoms, stop driving and get it inspected immediately.
When should I replace my engine oil cooler?
You should replace your engine oil cooler when you experience:
- Oil or coolant leaks near the oil cooler
- Engine overheating without other causes
- Oil in the coolant or coolant in the oil (may look milky)
- Drop in engine performance or efficiency
In general, an oil cooler may last 100,000 to 150,000 miles under normal driving conditions, but performance or heavy-duty vehicles might need earlier attention.
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What happens when the engine oil cooler fails?
When the oil cooler fails, several issues can occur:
- Overheated engine oil – reducing its lubrication properties
- Contaminated oil – if the internal barrier fails, coolant can mix with oil
- Loss of oil pressure – leading to engine knocking or seizure
- Coolant loss – which causes overheating and potential head gasket failure
A failed cooler can have a domino effect, damaging critical engine components.
What are the symptoms of a failing oil cooler?
- Visible oil or coolant leaks
- Milky oil or coolant (sign of mixing fluids)
- High engine temperature or overheating
- Low oil pressure warning light
- Reduced engine performance
- Burning oil smell or smoke from the engine bay
If you spot any of these, have your system diagnosed before further damage occurs.
Can an engine oil cooler be repaired?
In most cases, engine oil coolers are not repairable, they are typically replaced. That’s because:
- The internal passages are hard to access
- Leaks or cracks in the core can’t be reliably sealed
- Repaired units often fail again under pressure or heat
However, if the issue is a leaky fitting, loose hose, or gasket, those components can be repaired or replaced individually.
