OK so I have a hiss and no boost at low rpms

[2000_f350]

Just like it says. A few days ago it got cold. Highs in the 30's and lows in the 20's. Not close to as cold as it will get here in Indiana. Any way I noticed a hissing sound under the hood and no boost at low rpm's. As soon as it's over 1500 rpm's evbp or what ever it's called closes and the boost comes up. I am guessing that is what is causing it. Anyway it does it all the time. Eben after the truck is warmed up. Even though warm for my truck is at the bottom end of the gauge. Starts and runs fine other than that. I thought maybe I should plug it in but it doesn't act like it has trouble with the cold. It might lop once or twice when it starts but thats it. Any ideas what it might be?

[strokethis02]

same problem...curious what they have to say..

[Cjcross22]

Just the EBPV, mine will still do it after I have drove over an hour. I just sit back and enjoy the noise bouncing off buildings!

[jesilvas]

May wanna spray some lube on it. Might be sticking some.

[Cjcross22]

Yeah if it keeps doing it for a second or two after you hit the brakes or get on the throttle it may need some lube.

If it stops when you do either then you are good to go.

[2000_f350]

Originally Posted by Cjcross22

Yeah if it keeps doing it for a second or two after you hit the brakes or get on the throttle it may need some lube.

If it stops when you do either then you are good to go.

MIne will do it nonstop at low rpm's. It wont close untill I get on it. It will stay open crusing 35 mph.

[Cjcross22]

Sounds normal, mine has done it at 2k running down the highway around 65 or so.

It also does it at low RPMs as well, but yeah it sounds like its working fine when you let off or get on it

Mine eventually stopped chirping going down the highway then started back up when i was riding around in first gear in a parking lot.

[jesilvas]

I'm not sure if it should be closed at 2k RPMs driving.

[Cjcross22]

Eh I didn't think so either, it was extremely loud!

I still think it was fairly cold as well, but not sure? It quit doing it pretty soon after it started.

[NCHornet]

At 2000 rpm's it should be open unless it is just frigid!! Low rpm's and cold weather is totally normal. Why can't we get a sticky for " Loud hissing noise when cold" This is the third one in 3-4 days that I have replied to. As soon as it get's cold we see this threads like crazy, as well as "My truck is hard to start" I thank Dave for finally making the GP troubleshooting write up a sticky!!

NCH