Powerstroke hissing when cold

[Mopower]

My 1995 7.3 makes a hissing noise for a second when I fire it up BUT when it is cold it will do it down the road whenever it is not under a load. Sounds like a big blower hissing out my tailpipe. If you really stomp on it, it stops but as soon as you let up it goes back to hissing. Wastegate? I sem to have heard it on other trucks when it's cold. I just hate it bogging down. If I let the truck sit shut off when it is warm it usually runs ok when I fire it back up. Ideas?

 

[Allan in NE]

That's the darned exhaust gate that is supposed to speed warming the engine. Restricts the exhaust to make 'er work a little.

Very noticeable on the 7.3s and should open up after the engine comes up to temp.

Allan

 

[Haywood]

EBP Exhaust back pressure device.
They are very loud in a rear engine School Bus.

The tube from the manifold to the EBP sensors can plug with soot and throw codes.

 

[Superih]

Exhaust back pressure valve- is actuated by the ECU to restrict exhaust to work the engine and aid warm up at an idle. It is located at the end of the turbo just before the downpipe. When you press the throttle exhaust back pressure increases and the exhaust back pressure sensor tells the ECu to open the valve.

 

[cjcocn]

I agree with the previous two responses.

You can find a write-up on how to remove and clean your EBPS here:

http://guzzle.rbmicro.com/ebps.html

Also, if you navigate to his homepage you can browse for other tips on the 7.3.

HTH

 

[skyharborcowboy]

Go to this website to find out way more then you will ever want to know about Ford Diesels.

www.thedieselstop.com

That noise in 100% Normal!

Joe