Had a couple weird issues come up

[Mark Hood]

Hi all

Yesterday I noticed that my 17 3500, 6.7, Aisin did a couple things that has me scratching my head.. After coming to a stop and at idle for 20-30 seconds the sound of the engine gets a little louder and deeper in tone.. not a lot, just enough to notice. If I increase the rpm’s and come back to idle it sounds normal for 20-30 seconds and then gets a little louder.. it’s like something opens up? Would the cooler temps have any affect?

I also had a situation where I put the truck in park and when it did there was a loud “sharp” sound. I went to drive and back to park and it did it again.. after that it didn’t do it anymore.. I only have 14kon the truck..

Any ideas

Mark

 

[SnoKing]

Is it really cold and the exhaust brake is coming on?

 

[sag2]

EGR bypass opening?

 

[Mark Hood]

Is it really cold and the exhaust brake is coming on?

Hi,

well temps are dropping some (50’s) it is just odd, not a loud obnoxious increase.. like I mentioned it gets a deeper tone and a little louder like someone cracked a window. I have only had the truck 4 mo and never heard it before ( I am very OCDish so new sounds, rattles, etc drive me crazy). The rpm’s do not change

Thanks.

Mark

 

[Mark Hood]

EGR bypass opening?

Hi,

not sure.. I am a relative diesel newbie and have only had the truck 4 mo…


Thanks

Mark

 

[SnoKing]

Hi,

well temps are dropping some (50’s) it is just odd, not a loud obnoxious increase.. like I mentioned it gets a deeper tone and a little louder like someone cracked a window. I have only had the truck 4 mo and never heard it before ( I am very OCDish so new sounds, rattles, etc drive me crazy). The rpm’s do not change

Thanks.

Mark

Are you pushing the button for the exhaust brake to be enable right after starting the truck? If so try NOT enabling it and see if the change still occurs. When it is cold out, and the exhaust brake is enabled, it will idle on the exhaust brake until it gets up to operating temperature.

 

[lpennock]

Sounds like it is going into regen. Can you take it for about a 1hr highway trip pulling a trailer or other load to see if it goes away after that?

 

[bcbender]

yep... I have noticed when my truck is in regen in town, it has a louder tone once or twice. Check the EVIC and see if when you hear it the DPF screen says its in REGEN.

 

[Mark Hood]

Thanks, I will c,heck it out!

 

[Mark Hood]

How about the shift into park noise. It only did it a couple times

mark

 

[AH64ID]

Park shuts off the regen. I agree with others that it was doing a normal regen, which occurs about every 24 hours of engine run time. It’s hard to notice while moving, but stop and go you can gear it.

 

[Tuesdak]

I also had a situation where I put the truck in park and when it did there was a loud “sharp” sound. I went to drive and back to park and it did it again.. after that it didn’t do it anymore.. I only have 14kon the truck..

Any ideas

I would suggest while loaded: set the parking brake, shift to N, release the service brakes so the truck settles on the parking brake, then shift to "P". This will keep excessive load off the park pawl that can torque lock in "P" and strand you. Rare cases it can break. Esp. if you let the truck roll till the pawl drops in.

Sometimes the engine has a slight throttle, regardless of if your foot is on it or not, that is winding up the drivetrain. Shifting out of gear unloads everything suddenly and I have had quite a bang now and then. Shift and pause at "N" a moment rather than slamming it in Park. And even doing that it can bang unloading the driveline.