Four Signs of a Bad EGR Valve

If you’ve been driving or servicing a diesel truck for a while, chances are you’ve dropped a few expletives over trouble with your aftertreatment system. Many of the problems begin with the EGR Valve, which controls the flow and recirculation of exhaust gases through the system. One of the more common faults is a valve that sticks open which sets off a number of performance issues that are relatively easy to diagnose.

Based on our experience, we’ve compiled 4 easy indications that you’ve got a bad EGR Valve and might want to consider swapping out for a new, improved and coreless EGR valve replacement.

  1. Check Engine Light - obvious, we know, but it’s also one of the most reliable indicators of trouble with your EGR Valve. While that indicator light can mean other issues as well, it’s generally a good idea to have your engine hooked up to see if it’s throwing out an EGR Code. It’s possible that you light could go on before you start to encounter true performance issues, but with an EGR Valve those issues aren’t far behind.
  2. Rough Idle - this is particularly true when the Valve becomes stuck open, which causes the recirculation process to occur at idle. No bueno.
  3. Engine Performance Degradation - typically the next thing to follow that rough idle, is poor engine performance on acceleration. A loss of horsepower as you work your way to speed is the the most common trouble spot. That bugged up valve is messing with the air-to-fuel ratio of your truck which can lead to the aforementioned performance issues and even reduced fuel economy.
  4. Black Smoke - not gonna lie, while big black plumes pouring out of chrome stacks looks cool, it’s generally an indication of EGR Valve trouble. In fact, it’s one of the first questions we ask when a driver questions the integrity of his EGR Valve.

None of our signs of a bad EGR valve are too Earth-shattering, but a good process to work your way through as you try a little self diagnosis of your engine trouble. The team here at BIG Machine Parts got our start with aftertreatment systems, so if you’ve got questions, we’ve got answers. We're always happy to help. 

Check out the BIG Collection: EGR Valves

2 comments

By Jose, on

I have an 06 Freightliner Columbia with a Detroit 60 series 14l and I don’t have any power I have loss of power acceleration I think my EGR valve is bad

By Richard Kerr, on

Iam stumped, I have a 2014 kenworth with the ISX 550.
Thurs last week I had to add a half gal of coolant yesterday as Iam going down the highway a low coolant symbol shows up, but it’s not low and goes off after 2 to 5 minutes .
Engine temp rises and at 200 it returns. Exhaust pipes are white , haven’t seen white or black smoke. What’s going on with this engine. No visible leaks anywhere.

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