Symptoms of a Bad or Failing Oil Cooler Hose (Automatic Transmission)

The transmission oil cooler hose on a car helps to carry the transmission fluid from the transmission to the transmission cooler. The oil cooler is designed to lower the temperature of the transmission fluid to make it easier for the internal parts of the transmission to use. There are two types of transmission coolers, the type found inside the radiator or the kind that is external to the radiator that usually sits in front of the AC condenser. The oil cooler hoses are made of both rubber and metal. Usually, these hoses will run from the cooler to the transmission, where they will screw in. Without these lines doing the job that they are intended for, it will be impossible to keep the transmission cooled down.

The heat of your car’s transmission can be very damaging to the components it houses. Over the years, the rubber on the oil cooler hose will begin to show signs of wear. Having a damaged oil cooler hose can lead to a number of different issues that can compromise the overall functionality of your vehicle.

1. Visible damage on the hose

From time to time, it is a good idea for you to inspect the components under your hood. When performing this type of inspection, you will have to take a look at the transmission cooler hose. If you notice that there is visible damage to this hose, then you will have to act quickly. Getting this hose replaced before it fails completely can save you a lot of trouble.

2. Leaking oil around the lines

The next thing that you may notice when it is time to replace your oil cooler line is oil leaking around the fittings of the hose. Usually, these hoses will have “O” rings and gaskets that will seal the compression end of the hose. If these gaskets become damaged, it will be very hard or the oil to stay in the lines as intended as this is a pressurized system. As soon as the oil is noticed, you will need to get a replacement to avoid losing too much fluid.

3. Transmission overheating

When a transmission oil cooler hose fails it can cause the transmission to overheat. This can be due to low fluid level from a leak or preventing flow. In either case if the transmission overheats it can stop working entirely and this condition may be permanent. If the transmission is overheating it will generally set a Check Engine Light.

4. Deterioration in the rubber portion of the hose

If you start to notice that the rubber part of the oil cooler hose is deteriorating, then it is probably a good idea to have it replaced. When the rubber shows signs of wear, it will only be a matter of time before it begins to leak. Getting the hose replaced is the best way to reduce the chance of an oil leak.


Next Step

Schedule Vehicle Drivetrain Inspection

The most popular service booked by readers of this article is Vehicle Drivetrain Inspection. Once the problem has been diagnosed, you will be provided with an upfront quote for the recommended fix and receive $20.00 off as a credit towards the repair. YourMechanic’s technicians bring the dealership to you by performing this job at your home or office 7-days a week between 7AM-9PM. We currently cover over 2,000 cities and have 100k+ 5-star reviews... LEARN MORE

SEE PRICING & SCHEDULING

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Recent Vehicle Drivetrain Inspection reviews

Excellent Rating

(5)

Rating Summary
5
0
0
0
0
5
0
0
0
0

Eliud

23 years of experience
200 reviews
Eliud
23 years of experience
Ram 1500 V6-3.6L - Vehicle Drivetrain - Snellville, Georgia
Eliud was punctual and knowledgeable about my vehicle. Solved the issue within the half hour

Richard

35 years of experience
96 reviews
Richard
35 years of experience
Mercedes-Benz CLS550 V8-5.5L - Vehicle Drivetrain Inspection - New Port Richey, Florida
Came out on time took 40 min test drive found problem and ran scan to show the problem and I would recommend him highly knows his job well ! Thanks you Richard !

Kevin

24 years of experience
532 reviews
Kevin
24 years of experience
Honda CR-V L4-2.4L - Vehicle Drivetrain Inspection - Lilburn, Georgia
I'm glad we got the 50 point inspection because the actual issue was different than what I thought.

Darnell

19 years of experience
21 reviews
Darnell
19 years of experience
Pontiac Fiero V6-2.8L - Vehicle Drivetrain Inspection - Inglewood, California
VERY PLEASANT AND INFORMATIVE!

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.

GET A QUOTE

Related articles

How Long Does an Oil Cooler Hose (Automatic Transmission) Last?
Keeping Keeping all of the fluids in a car at the right temperature is very important. Having too much heat in the engine can cause a lot of damage. The various parts of the cooling system help to regulate the...
How to Replace a Radiator Hose
The The radiator hose is an important part of your vehicle’s cooling system. The hose carries the coolant to the radiator, where the fluid is cooled, then back to the engine to keep the vehicle from overheating. This allows your...
How to Replace a Secondary Air Injection Hose
A car's secondary air injection system allows oxygen into the exhaust. If a hose is faulty, a car may have increased emissions and performance issues.

Related questions

Codes showing: P0171, P0420, P0174
Hello. These diagnostic trouble codes are an indication that there could be a problem with the oxygen sensor (https://www.yourmechanic.com/article/symptoms-of-a-bad-or-failing-oxygen-sensor) or that there is a vacuum leak (https://www.yourmechanic.com/article/symptoms-of-a-bad-or-failing-vacuum-hose-s). It is possible that the vacuum leak is located in the intake manifold....
Octavia won't start
Hello. From what you describe, it appears that your vehicle may be having more than one problem. A no-start condition will be caused by a different set of issues then a flashing oil light. A no-start condition can be caused...
2004 5.3 Tahoe oil pressure drops when stopped, rises when accelerating, sounded like an exhaust leak to, blow whit smoke on crank
Hello, thank you for writing in. The smoke on start up is usually due to the valve stem guides and or seals. They may need to be replaced. As far as the oil pressure is concerned, you need to check...

How can we help?

Our service team is available 7 days a week, Monday - Friday from 6 AM to 5 PM PST, Saturday - Sunday 7 AM - 4 PM PST.

1 (855) 347-2779 · hi@yourmechanic.com