Skip the auto shop - Our mechanics make house calls
  1. Home
  2. Articles
  3. Symptoms of a Bad or Failing EGR Cooler

Symptoms of a Bad or Failing EGR Cooler

EGR cooler

The EGR cooler is a component used to lower the temperature of the exhaust gases that are recirculated by the EGR system. The EGR system recirculates exhaust gases back into the engine in order to decrease cylinder temperatures and NOx emissions. The gas circulated by the EGR system can be considerably hot however, especially in vehicles equipped with diesel engines. For this reason many diesel engines are equipped with EGR coolers to lower the temperature of the exhaust gases before they enter the engine.

An EGR cooler is a metal device that employs thin passages and fins to cool the exhaust gases. They function in much the same way as a radiator functions, by using the cool air passing through the fins to cool the exhaust gases as they flow through the cooler. When the EGR cooler has any issues, it can cause problems with the functionality of the EGR system. This can lead to performance issues, and even problems with passing emissions standards for states where they are required. Usually a bad or failing EGR cooler will produce a few symptoms that can alert the driver of a potential problem that should be serviced.

1. Engine overheating

One of the first symptoms of a potential problem with the EGR cooler is engine overheating. If the EGR cooler has any issues that restrict the flow of exhaust gases through the cooler it can cause the engine to overheat. Over time, carbon can build up on the inside of the EGR cooler and restrict flow through the cooler. This can cause the unit to overheat, at which point it will not be able to cool the exhaust gases, and the engine will overheat as a result. Engine overheating can lead to knock or ping from the engine, and even serious damage, if the issue is left unattended.

2. Exhaust leak

Another issue of a problem with the EGR cooler is exhaust leaks. If the EGR cooler gaskets fail, or the cooler gets damaged for any reason, it can cause an exhaust leak to develop. An exhaust leak may be heard as an audible hissing or tapping sound coming from the front of the vehicle. This will reduce the efficiency of the EGR system, and negatively affect engine performance.

3. Check Engine Light comes on

Another symptom of a bad or failing EGR cooler is a Check Engine Light. If the computer detects a problem with the EGR system, such as insufficient flow or exhaust, it will set off the Check Engine Light to alert the driver of the issue. A Check Engine Light can also be set off by a wide variety of other issues, so having the computer scanned for trouble codes is highly recommended.

EGR coolers are not found on all vehicles, but for the vehicles that are equipped with them they are critical to the performance and driveability of the vehicle. Any problems with the EGR cooler can also lead to increased emissions, which will be a problem for states that require emissions testing for all of their vehicles. For this reason, if you suspect that your EGR cooler may be having an issue, have the vehicle inspected by a professional technician, such as one from YourMechanic, to determine if the cooler should be replaced.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
Still not sure about your car's issue?
Diagnose your car
What kind of issue are you experiencing?
Brakes are squeaking
Car is not starting
Car is overheating
Car is shaking (vibrating)
Fluids are leaking
Heating and A/C
Smoke or steam is coming out of the car
Warning light is on
Icon-warranty_badge-02

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

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

More related articles

Veteran and Military Driver Laws and Benefits in Idaho
The state of Idaho offers a number of benefits and perks for those Americans who have either served in an Armed Forces branch in the...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...
P2159 OBD-II Trouble Code: Vehicle Speed Sensor B Range/Performance
Diagnostic Trouble Code (DTC): P2159 P2159 code definition Vehicle Speed Sensor B Range/Performance...


Related questions

Q: Coolant seems to disappear

If this "just started", it may be that there was trapped air in the system, since you did the water pump replacement, and so all you are doing is providing make up coolant at the moment. But, if the coolant...

Q: 2005 Chrysler 300c has a code P0406. I believe EGR needs replacing, Don't know if it will make it 25 miles to dealer.

P0406 involves the EGR system but that may or may not be the only factor causing your rough running condition. Typically, P0406 will set if you have a failed EGR valve, excessive carbon buildup, an open or short in the...

Q: Blue smoke black smoke white smoke what do they mean

Hello. If there is blueish smoke coming from the exhaust, then that is an indication that the engine is burning oil. This can come from the valve stem seals or from the piston rings. It can also come from the...