I have a bone stock 2007 6.7.

I just took my truck to the dealership to get a major service done. The service included an oil change, front and rear diff service, coolant change and EGR cleaning.

After the service was done, the CEL popped a total of 5 times in the time frame of 3 days. It was the P0489 code which signified "EGR flow sensor low." Since I just got it back from the dealership, I figured that the CEL was residual feedback from resetting the sensors, etc. After it popped and I cleared it for the 5th time, I took the truck on a 'long' distance trip of appx 300 miles round trip and the truck behaved better and no CEL popped.

However, 1 out of every 6 starts or so, the engine would run erratically. I would start the engine and when I would press the gas and get the engine to about 1000 rpms at idle, the engine would surge to about 1300 rpm and settle back to 1000 and it would do this over and over again until I let my foot off the gas. I would then turn the engine off, wait a minute, start it up again and the symptoms would go away.

My sense is that the EGR may have not been reinstalled correctly or the sensor is malfunctioning or both. Anybody have any insight to what this might be?

 

The EGR valve needs to be replaced, read diagnostics

 

Thanks. When I brought it back to the dealership, they were able to fix it. The service advisor told me that they took the EGR apart and noted that there was some residual moisture inside. They subsequently cleaned it up and now the truck runs fine without any CEL or erratic engine behavior (crossing my fingers, knocking on wood).

Thank you for the input.

-WB

 

I hope they made sure it wasn't engine coolant. The EGR cooler is cooled by engine coolant. If the cooler starts leaking you will get coolant into the EGR valve and crossover tube. Mark your coolant bottle at the current level of coolant. If the coolant level starts to drop then you could have EGR cooler leaking. Hot exhaust goes into the EGR so any residual EGR cleaner would have been blown into the engine. You would get overheat condition if EGR cooler is leaking. You will also get white smoke out the tailpipe if leaking coolant into egr system.

 

^^^^^ Props to BigIron70......he's invaluable around here. His knowledge of these trucks/engines is second to none.

Job well done sir!!!

 

Awesome, thanks BigIron. I'll do exactly what you mentioned above. I wish I read this earlier right when you wrote it. I'm not getting the check engine light anymore and I've driven the truck pretty hard just to make sure that it doesn't pop again. So far, it hasn't. I do check under my truck every morning whether I drive it or not (I mostly ride a motorcycle to work). We recently had our undeground garage power-sprayed so all the stains that have been there before we moved in are gone. This will help me check for oil/coolant/fluid leaks in the future.

Thanks.