[MustangMatt96GT]

I noticed today after rapping up 1st gear really fast WOT, I heard a slight noise (can't really describe it), but i have a feeling it was my belt starting to shred from the quick spool up and RPM change. I have now changed my belt after the first strand had started to go. I put on a Gatorback, and the noise has not come back at all yet.

So as i was driving back to school, i was idling at a stop light and the truck was vibrating more and on and off, also you could hear a difference in the idle. After checking vitals (i know our dummy gauges, but they read good) i watched the tach. and every time it would start vibrating more (slightly, feels as if its running rougher) and sound a little different the RPMs dropped a bit. I turned off all my accessories (just the radio at the time being) thinking maybe im having a charging issue. Not the case. So i turned on the A/C to see if maybe the clutch in that is having an issue, again not the case, it surged with it off and on. The surging is also random, no pattern to it that i can tell.

Another item worth noting, i popped the hood when i got home, let it idle for a minute or two while i was listening in under the hood. I go and turn the truck off with the ignition, and go back under the hood, and I can hear a leak (sounds like an air Hiss) of something coming from the passenger side.

Wondering what your guy's ideas are.

The truck does have a CEL, but its been on for about a month now, My drivers side glow plugs are reading too much voltage indicating a few are bad. Have not changed them yet, so the CEL keeps coming back. Would an idle issue like this possibly have set a code, but i dont know since the CEL was already on?

Thanks

Matt

 

[blageurt]

The hissing could be a leaking intake vibe , like the map sensor tube , intake boot could be torn , Clamp on intake could be loose , o- ring inbetween Turbo and "y" could be dusted, or all of these things .How much boost are you making ? It should be at least 14-17 psi @ wot

 

[brooksbronco17]

That hiss could be the A/C equalizing and nothing related to your problem. Just a Thought. Could it be the ebpv actuating causing the change in RPM's? Mine did that but it was going down the road and would feel like the motor was bogging down and when i hit the go peddle it would stop. With your glowplug readings I wouldn't eliminate the Under valve cover harness either.

 

[MustangMatt96GT]

Well... I dont think its the under valve cover wiring harness, no burned smells and the harness looks good from what I can see of it.

I also took the truck across town today (25 miles) and i noticed that i can hear the turbo spooling up(never been able to before) No notice in loss of power.

So now i guess i got to find out where its leaking at or what line i blew off.

I also wish I had a boost gauge. I dont know what the truck is making, but i do have a triple pod pillar, just need the gauges.

So what are the easiest ways to find a vaccumm leak or where this thing might be hissing. I think ill have a friend rev it to around 1800 RPM and use a hose to see if I can pin point the new Leak that is allowing me to hear my turbo.

 

[blageurt]

The only place you will have a vacuum leak is at the booster or the Vacuum pump line or the tree where all the vacuum lines connect along with the heater /defroster and the locking hubs if you have a 4x4 . Diesels make pressure , NOT vacuum that is why we need a vacuum pump to create vacuum. If your power is normal like you say and cannot detect any boost readings then check around the vacuum pump or brake booster for the vacuum leak.

 

[MustangMatt96GT]

well now I'm wondering about if maybe I broke a body mount. I feel the vibratin in the cab of the truck, but not when my hand is on the valve cover.

Where would the vaccum pump be though?

 

[bluenavigator]

Viewing toward the engine as hood is up, the vaccum pump is on driver's side, just below the A/C compressor. Below that vaccum pump, the next thing is power steering. So you know where to look at.

 

[grspowerstroke]

The shaking could be your dual mass flywheel. Can you hear some clattering when you shut it off? Either way, take off the cover below the flywheel and check if you can rotate the two halves with respect to one another.

Not sure about your hiss, but I could hear my turbo spool really well after playing with the downpipe and not getting the banjo fitting back on the turbo/downpipe connection tightly. I guess if you jumped out of your truck fast enough after turning it off, and that connection was open, the turbo could still be spinning and causing an air hissing sound. Just a thought.

 

[MustangMatt96GT]

Second guy to recommend the dual mass flywheel... thinking this might be it

I will take the cover off tomorrow and see what i can do. The truck's clutch does kinda chatter a little bit.

But i do not hear any noise, what would i be listening for?

And the Hissing part must have been from having the A/C on, because i have not heard it ever since i had the A/C on.