Hissing dropping pressure when cold

[jeeps and fords]

My truck when it's cold and even when it's up to temperature it will drop pressure while idling or driving which also drops the rpms. I am just wondering if there is any tip or trick as i've heard this is normal for a cold turbo.

 

[Frankenstien]

This is normal. You have an EBV (Exhaust Backpreasure Valve) That actuates, this limits or restricts the exhaust as it enters the hot side of the turbo, The purpose is to aid your engine in Warmup cycle. It should only (in normal circumstances) actuate only at Idle or when you are not accelerating. this Valve can also be modified to be used as a weak exhaust brake.

 

[jeeps and fords]

See that's where I was curious as the truck will do it even while driving with foot on the accelerator unless you hit on it hard which I don't like to do.

 

[JRNOLL]

My truck does the same thing ,until throughly warmed up ( about 10 min.)then it stops doing it. Only happens when it's below 40 F.

 

[BIG JOE]

Kinda simply put ?

The EBPV (exhaust back-pressure valve), the HIC (high idle circuit), the AIH (air intake heater) and a number of other power & performance components.. are.... controlled & activated, some are deactivated.. by the outside (ambient) temperature inputs (values) sent to the ECM (engine control module).. when we turn the ignition key on... in cold(er) weather.

Most are controlled by the EOT (engine oil temperature) and ECT (engine coolant temperature) sensors.

Until those sensors send (warmer) temperature values to the ECM that are within normal operational (required) limits (values).... We will Hear, Feel and Smell stuff, that isn't Normal...

Not To Worry. The Cold Start systems are doing just what the EPA, Ford & IH want them to do.... a faster warm-up... to reduce pollution.

Some will "turn off" sooner than others.. so we're not stuck or stranded.. but our PSD's won't sound, feel or smell normal, 'til Normal operational Temps are achieved.

Maybe a "Duh" to some.. But hope this helps ?

 

[jeeps and fords]

See that's the other thing my gauge will show it up to temperature but still seem to do it as I let my truck warm up and even use a separate high idle setting on my chip.

 

[BIG JOE]

If it's the Ford temp gauge yer looking at.. ignore it's accuracy.

After 10 minutes of warm up~driving, does all this go away* ? Performance normal ? Dropping pressure ?

If so, what yer hearing could be.. The fan clutch engaged.. as well as the EBPV being closed, or even a leaking/loose I/C charge tube boot clamp.. or an intake plenum boot clamp.

Give all the clamp nuts, a Turn, or So



*Might be something yul halfta live with. These dezels need to be warmed up.. to run & sound right.

 

[iracemine]

I thought we stickyed a hissing sound thread?????

 

[bigrigr]

X2 Sure sounds like a loose/torn ic boot leak if it's not the ebpv. Just unhook the ebpv connector and see if it changes anything.

 

[Big Black]

hissing sound

My '00 Lariat has never done this nor my '99 XL dually however my '99 XLT SRW 4wd just started doing this. I have warmed the truck up for 20+ min. and it still does it for quite some time after starting to drive it. Throttle is non responsive at times and when the truck does this it drinks the fuel. Normally this subsides about 15 min. into the drive, however I would like to resolve this ASAP.

Thx Jimmy