Sounds like an exhaust brake

[13MWZ]

I'm sorry for the repost. I posted this question in another thread and after 100 views still havent gotten any responces. I'm hoping somebody who reads this can give me some insite.



My truck is a 06 2500 4x4 auto. Resently I have started to notice a sound when I'm coming to a stop. It always happens at the same time, just before the 2 to 1 downshift and lasts for about 1-2 seconds. It sounds like I have an exhaust brake... ... but I dont.

On my old 97 F350 Powerstroke it had what was refered to as a EBV (exhaust backpreassure valve) that acted as an aid in warming the engine up after cold starts. It was a butterfly valve that would close partialy for cold starts. Folks messed with it and were able to use it as an exhaust brake. Anyways, Does the CTD have something similar? On the PSD is was just behind the turbo. I havent stuck my head up in there lately but I dont recall seeing any linkages or anything going to the down pipe or any in that area atall besides the wastegate. Any ideas on what could be causing this sound?

At firs I thought maybe tires (my old mud tires use to make a simialr sound when rolling slowly), but they are brand new all-terrains and have the right air pressure. Then I touht maybe brakes but they check out too. Then the EBV thing hit me. I'd appreciate any ideas.

 

[ed9824v]

I'm sorry for the repost. I posted this question in another thread and after 100 views still havent gotten any responces. I'm hoping somebody who reads this can give me some insite.



My truck is a 06 2500 4x4 auto. Resently I have started to notice a sound when I'm coming to a stop. It always happens at the same time, just before the 2 to 1 downshift and lasts for about 1-2 seconds. It sounds like I have an exhaust brake... ... but I dont.

On my old 97 F350 Powerstroke it had what was refered to as a EBV (exhaust backpreassure valve) that acted as an aid in warming the engine up after cold starts. It was a butterfly valve that would close partialy for cold starts. Folks messed with it and were able to use it as an exhaust brake. Anyways, Does the CTD have something similar? On the PSD is was just behind the turbo. I havent stuck my head up in there lately but I dont recall seeing any linkages or anything going to the down pipe or any in that area atall besides the wastegate. Any ideas on what could be causing this sound?

At firs I thought maybe tires (my old mud tires use to make a simialr sound when rolling slowly), but they are brand new all-terrains and have the right air pressure. Then I touht maybe brakes but they check out too. Then the EBV thing hit me. I'd appreciate any ideas.

what about pressure release through wategate, if I get on the engine hard and let off there is a wierd sound of the wastgate getting rid of extra pressure in the turbo. Ed

 

[cojhl2]

what about pressure release through wategate, if I get on the engine hard and let off there is a wierd sound of the wastgate getting rid of extra pressure in the turbo. Ed

Rather than the wastegate, in the circumstance you describe Ed, that would be the turbine in a stall.



That could be his sound but I took his situation to be already off power for a spell when this noise occured.

 

[13MWZ]

That could be his sound but I took his situation to be already off power for a spell when this noise occured.

Yes your right. It's while I havent had my foot on the go pedel for a bit, and only just before the 2-1 downshift. So it aint the wastegate.



Also if it helps with anything, this sound doesnt seem to be speed related at all. It does it just the same if I hit the brakes hard as it does if I'm just slowly coming to a stop. And now that I think of it... ... it must be something with the engine/exhaust because I didnt notice it untill I junked my muffler.

 

[JDiepstra]

Can you explain the sound a little better? Is it whistle like, or more of a roar and rumbly like a semi Jake? Does your engine RPM increase during the 2-1 downshift? Could it be turbo noise out the straight pipe?

 

[13MWZ]

It's not a whistle. It's a rumble, not sure how else to explain it other than just like an exhaust brake. I still have the cat on the exhaust and while I can hear the turbo whistle through the intake (removed silencer ring and the fin thing between the turbo and intake) it isnot the same noise as I'm talking about. I wish i could record it or something so yall could hear it.