Here are some steps for the average do-it-yourself mechanic to replace the oil cooler hose in a few hours.

Pretty sure you can’t just plug the lines. 100% of the oil supply to the engine goes thru the cooler, so plugging the lines would starve the engine of oil. Transmission oil coolers can leak into the coolant, too, so be sure that is not the issue. …

How to Replace Chevy Truck Oil Cooler Lines

1. Lift up the vehicle using the jack and place it on jack stands.
2. Drain the oil from the oil pan into the drain pan by unbolting the drain pan bolt using the 3/8-inch ratchet and socket.
3. Unscrew an oil cooler line from the radiator using the line wrench.

1. Step 1: Locate Oil Cooler Hose.
2. Step 2: Disconnect Hose from Radiator.
3. Step 3: Disconnect Hose from Oil Pan.
4. Step 4: Remove Line Holders.
5. Step 5: Remove Oil Cooler Hose.
6. Step 6: Install New Oil Cooler Hose.

It usually means oil is leaking into the cooling jacket through a leaking head-gasket. An alternate explanation might be transmission fluid (which would appear as oil) leaking into the radiator from the transmission cooler (which is often part of the radiator).

Since oil is lighter than water most of the oil in your cooling system will float to the top of your radiator or coolant overflow tank. If you see an oil slick floating on your coolant it’s important to clean out your cooling system to make sure your engine doesn’t overheat.

Overheating – If coolant mixes with the oil, the engine will not be able to cool or lubricate itself properly. This can result in overheating and increased engine wear. Keep an eye on your temperature gauge and refrain from driving if it gets too high.

As it chemically removes electrons from the metals of cooling system components, distilled water eventually does extreme damage that could lead to cooling system failure.