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

How to Find the Keyless Code on a Ford Explorer or Mercury Mountaineer
Many Ford Explorers and Mercury Mountaineers were manufactured with an option known as the Ford keyless entry keypad. Some models refer to it as SecuriCode as well. It...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the...
P0222 OBD-II Trouble Code: Throttle/Pedal Position Switch/Sensor B Circuit Low Input
P0222 code definition Throttle/Pedal Position Switch/Sensor B Circuit Low Input What the P0222...

Related questions

Q: Temperature guage stays on cool, heat inside is not very warm

If your heater is not getting warm enough and the engine is not reaching operating temperature for a long time then your engine most likely has a thermostat that is stuck open. A stuck open thermostat can be verified by...

Q: Starting issues, bucks and stalls during acceleration

The first issue of a no-start or a stall after starting is going to be a problem with the anti-theft system and maybe the ignition key or the key sensor intermittently not disabling the anti-theft system. This would need to...

Q: I'm not sure if I need a new timing belt & if I do, is it worth to get fixed?

Your engine actually has a timing chain (and associated parts) to keep the crankshaft and camshafts in a properly timed relationship. Your mechanic is correct that performing a timing chain service, which includes the chain, guides, tensioner and pulleys, then...