An oil cooler leak in your 3.5 Ecoboost engine can be the precursor to other problems. So what can you do to seal this leak? We researched this concern for you, and here’s the answer we found.
First, find the location of the leak in your 3.5 Ecoboost’s cooler oil reservoir. Generally, the leak might be coming from a worn gasket. If so, follow these steps to replace the seal with a new unit:
- Raise the vehicle
- Remove the oil filter
- Remove the oil cooler gasket
- Install the new oil cooler gasket
- Return the removed parts
- Fill the engine with oil
- Test the seal
Be wary as missing some details as you’re attempting to repair your 3.5 Ecoboost engine might bring about additional hazards. So continue reading as we talk about this procedure in greater detail.
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What Causes Oil To Leak From Oil Cooler Of A 3.5 Ecoboost Engine?
Oil cooler gaskets, particularly from Ford 3.5 Ecoboost engines, have seals that help keep the lubricant in the required places. But these gaskets may become loose or worn over time. Corrosion may also set upon these seals, causing the leaks. Other likely suspects of an oil cooler leak are cracks in vacuum pump hoses and manifold gaskets.
Leaks from Ecoboost engines may also come from other sources. You can read our post on the different reasons why an F-150’s engine leaks oil for additional information about that matter.
How To Find Leak In 3.5 Ecoboost Oil Cooler?
As its name implies, the oil cooler’s job is to cool the engine oil. This radiator-like system comes with different parts. That also means that a leak from a 3.5 Ecoboost oil cooler may come from different places within the assembly.
So, follow these steps to find the leak in your Ford engine’s oil cooler:
What You’ll Need
- Smoke machine
- Turn off your Ford vehicle’s engine and let it cool for a few minutes.
- Engage the hand or parking brake, then open the hood.
- Remove the brake booster hose from its terminal.
- Attach the smoke machine’s hose to the brake booster’s terminal.
- Turn on the smoke machine.
- Inspect the oil cooler for the specific location where the smoke appears.
Watch this video if you need a visual guide to this procedure. The clip also shows you what you’ll need to make a DIY smoke machine if you don’t want to spend the extra money on a new model:
You can also watch the following video if you’re curious about how an engine oil cooler works:
How To Fix A Seal In 3.5 Ecoboost Oil Cooler?
After finding the source of the leak in your 3.5 Ecoboost oil cooler, the next step is to seal it. Generally, you may only need to replace the gaskets on the assembly for the leak to disappear. If you found that the leak comes from worn seals, here are the steps to follow:
What You’ll Need
- Floor jack
- Jack stands
- Wheel chocks
- Drain pan
- Flathead screwdriver
- Panel remover
- Wrench set
- Ratchet and socket set
- Large cloth or towel
- Replacement oil cooler gasket
Step #1: Raise The Vehicle
Ensure that your Ford vehicle’s engine is off. Allow the engine to cool before continuing to the next part of this task. You’ll know when you can proceed if the hood isn’t hot.
Then, raise the front of the vehicle with the floor jack and place jack stands. The jack stands should help support the vehicle’s weight if the floor jack fails. Next, chock the grounded wheels to prevent the vehicle from moving while you’re working on it.
Step #2: Remove The Oil Filter
Go underneath the vehicle and locate the cooler oil filter. Once found, place a drain pan underneath a cutout below the filter. Make sure your drain pan is in place as loosening and removing the oil filter will let allow oil to escape its reservoir almost immediately.
You can remove the oil filter by using a wrench to loosen the drain plug. Then, use your hand or another appropriately sized wrench to remove the filter from its mount.
Watch the video below if you need additional help with this particular step:
Also, this clip shows you the common location of a 3.5 Ecoboost’s oil cooler filter:
Step #3: Remove The Oil Cooler Gasket
Use the appropriately sized socket to remove the bolts securing the oil filter housing. Doing so should also loosen the oil cooler gasket. Remove the oil filter housing afterward, which should expose the oil cooler gasket.
You can remove the oil cooler gasket by using a panel remover or flathead screwdriver. Wedge the panel remover or flathead screwdriver on a notch in the gasket. Then, pry that component from its mount using that tool.
Tip: Place a large cloth or towel underneath the vehicle's chassis. Oil from the cooler gasket may spill onto the floor.
Step #4: Install The New Oil Cooler Gasket
Place the new oil cooler gasket in the same location as the old unit. Generally, you only need to press the new gasket with sufficient force from your hands for it to sink into its mount. However, you still need to pay attention to the gasket’s orientation for it to fit properly.
Step #5: Return The Removed Parts
After a successful installation of the new oil cooler gasket, return the oil filter housing to its original location. Secure it and the rest of the assembly by returning their bolts. Don’t forget to return the oil filter as well.
Step #6: Fill The Engine With Oil
Refill the engine with the correct oil. Consult your Ford vehicle’s owner’s manual for the correct oil to use. For example, the 2021 Ford F-150 3.5L Ecoboost takes 6 quarts of SAE 5W-30 Synthetic Blend Motor Oil.
You can also watch the video below if you need help with changing your Ford’s 3.5 Ecoboost engine’s oil reserves:
Step #7: Test The Seal
Remove the jack stands and lower the vehicle to the ground. Turn on the engine and allow it to idle for a few minutes. Then, check if the new gaskets are functioning as intended.
Watch this video for a visual representation of this process:
How Much Does It Cost To Replace A 3.5 Ecoboost Engine Oil Cooler?
Professional automotive repair services to replace a 3.5 Ecoboost engine oil cooler cost about $238 to $270. Take note that the overall fees may vary depending on different factors, including the specific model of the vehicle and the repair shop’s location.
What Happens If The Engine Oil Cooler Is Bad?
Failure to repair an engine oil cooler’s leak may cause more severe symptoms to appear. Some signs to watch out for to know that your 3.5 Ecoboost’s oil cooler is faulty are:
- Coolant leaking to other parts of the engine
- Coolant mixing with engine oil
- Engine oil entering the vehicle’s cooling system
What Happens When Coolant Mixed With Engine Oil?
If the oil cooler leak from the 3.5 Ecoboost releases oil and it mixes with coolant, certain parts of the engine may malfunction. Failure to rectify this concern as soon as possible may lead to serious problems for the vehicle.
Bear in mind that engine oil and coolant have different formulas. Mixing the two substances may cause the ingredients to fail at completing their main responsibilities.
How Do I Clean An Oil Leak In My Garage?
After fixing your 3.5 Ecoboost oil cooler leak, you might see a spill or leftover puddle from the escaped liquid. You can clean this mess with these techniques:
- Use talcum powder. This product may help in absorbing motor oil, particularly if the puddle is reasonably small.
- Sweep the floor. Use a standard or bristled broom to remove the substance from your garage’s floor if it’s still in its liquid state.
- Brush with soapy water. Liberally apply a liquid detergent solution to the oil spill and use a brush to clean it.
Remember to find the leak in your 3.5 Ecoboost’s oil cooler before attempting to repair the assembly. If the oil cooler's gasket is at fault, you can use the steps mentioned in this post as your guide. An alternate solution would be to send your Ford vehicle to a reliable automotive repair shop if you need expert help.
If you’re looking for answers to other Ford engine concerns, read these great posts: