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

(11)

Rating Summary
11
0
0
0
0
11
0
0
0
0

Jay

38 years of experience
1035 reviews
Jay
38 years of experience
Toyota Tacoma V6-4.0L - Vehicle Drivetrain - Redlands, California
Jay was able to make a diagnosis. He gave me a few suggestions of what my options are going forward.

Victor

21 years of experience
72 reviews
Victor
21 years of experience
Lincoln Navigator V8-5.4L - Vehicle Drivetrain - Dallas, Texas
Victor is a great knowledge mechanic who knows what he is looking for and gets to the problem. Goes out of his way, in spite of the cold to make his customer happy. Came in time and advised me when he arrived, and explain to me what the problem was and I told him, "Yes, take care of it." and he did. Thank you very much. No excuses, like shops that tell you, "It is close to closing and we can fix tomorrow." Yolanda

Richard

36 years of experience
104 reviews
Richard
36 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 !

Keven

8 years of experience
187 reviews
Keven
8 years of experience
Nissan Versa L4-1.6L - Vehicle Drivetrain Inspection - Federal Way, Washington
He was kind and very knowledgeable about the job

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

Symptoms of a Bad or Failing Wastegate Hose
If you have a turbocharged vehicle, common signs include the Check Engine Light coming on, turbo not producing a boost, and decreasing fuel economy.
How Long Does a Vacuum Hose(s) Last?
Most Most car owners fail to realize just how important air flow is to the running of their vehicle. Nearly every system on your car requires air flow in order to function properly. The negative air flow, or vacuum, that...
How Long Does a Variable Valve Timing (VVT) Switch Last?
Having Having a smooth running car is no accident. A lot of different parts have to work in conjunction with each other for the engine to run smoothly. The variable valve timing (VVT) system has a lot to do with...

Related questions

Oil pressure
The first step is to check that your engine has the correct oil level (https://www.yourmechanic.com/article/how-to-check-your-engine-oil). If the vehicle has enough oil, the problem is probably with the engine. A worn oil pump, restricted oil passages, or worn engine bearings will...
Radiator hose rubbing pulley after minor accident
Thanks for inquiring about your vehicle. A collision specialist needs to examine the vehicle and YourMechanic does have specialists who could perform a mobile examination and arrange repairs. To save you some money initially you might attempt to contact a...
My car has low oil pressure. I've already changed the oil pressure sensor 3 times.
If you have replaced the sensor three times and it did not fix the problem, then you may have problems with the oil pressure being low at idle due to wear in the engine bearings. The reason it would be...

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 (844) 997-3624 · hi@yourmechanic.com