Whining noise when accelerating???
 

I have a whining noise when I accelerate moderately to hard. I really think it is the vp44 bc I can hear my turbo whistle as it spools up and you can tell its coming from the passenger side. This other noise I hear is coming from the driver side which is why I think it's the vp44. It only happens when I have a smarty tune on. If the truck is set stock, it doesn't do it even if I accelerate crazy hard through all 5 gears. It is throwing me off though bc the noise kinda "spools down" when I let off. Is this noise coming from the IP or is it likely just my turbo?

Check to see if the bolts on the intake manifold are loose. Sounds to me like you have a boost leak. Check all the boots and fittings, spray all of your boots with starter fluid and around your intake housing and see if it changes idle speed if it does its sucking air somewhere a long the line. But check the manifold first.

post a video of it....

okay I will tomorrow. I just got your post jigabop. it only happens when im accelerating in gear. it doesn't do it at idle.

video with audio can help use point you in the right direction. does free revving cause the noise? power braking? well if you have a stock clutch, power braking isn't the best idea to do...

I tried uploading the video of the noise. It won't upload. I will have to load it on my computer today then post it from my computer.

I noticed the same kind of thing happening to mine after having some issues after replacing a fuel filter cap. I ran some 2 cycle through it and it cleared right up.

I think I have a boost leak. The noise only happens when in gear driving and only under moderate to hard acceleration or in other words, when the boost is built up and when the boost drops, so does the noise. I recently removed the intake elbow off and on about 4 times working on my truck and after that is when the noise appeared. I may have damaged the elbow gaskets, so I am gonna try replacing them and see what happens. Bought 4 for 3 bucks each on genos garage.

build yourself a boost leak detector if you think you have a boost leak.

I built mine for about a $13 shopping trip at home depot...
Attachment 34844

just a threaded pipe plug glued and clamped in the end of a rubber pipe reducer that came with clamps. Drilled and tapped the pipe plug for an air compressor fitting to thread into the end. Just set the regulator on the compressed air, hook it up to the turbo and clamp it on, then hook the air hose to it and start squirting soapy water on any possible place boost can leak...

I will try that if the new gaskets do not work. But given the specifics of my situation, I think hopefully its the gaskets.

Still a good idea to make one. You would be surprised at how big of a leak you can have and still make tons of boost...

I made 65psi with a huge boost leak at my v clamp. I mean huge leak!

The engine would detonate if you ever attempted to put that much boost to it. I don't believe it, sorry. :nope::humm::w2:

you're welcome to come take a ride in it any time...

I push 72-75psi without the boost leak.

and during this dyno run I made 70psi on the dyno...


I run compound twin turbos.

57/65/14cm^2 over a 75/96/1.32ar

push 38psi from the S745 and 72-75psi total boost @ the intake manifold.

That 65-75psi is average boost level for compound twins. higher boost levels like the 1000hp+ sled pullers and drag racers run is in excess of 100-150psi from HUGE compounds.

So no, your engine is not going to "detonate"

You have much to learn :tu:

I do have supporting mods to keep it from floating valves or blowing a head gasket.

I run ARP head studs at 135lbs/ft and 115# valve springs and HD pushrods.

bigger picture of under my hood:

http://www.digital-anarchy.com/image...bc8ac865c7.jpg
http://www.digital-anarchy.com/image...bc8ac84214.jpg
pic from assembling the twins...just so you can see there are two turbos in there...
http://www.digital-anarchy.com/image...5608b26ef6.jpg
and the two turbos before they went in the truck...
http://www.digital-anarchy.com/image...4eb1bc0249.jpg

Looks sexy :)

hey guys. thanks everybody for all the replies and help. sorry i kinda just ditched the post for a while. i been busy with work. I made one of those boost leak testers and found that my 2 boots off the intercooler were loose and had slight leaks. but the major leak that was causing the whining noise i described was coming from the intake manifold. the first 2 bolts after the intake elbow were about 1/4 inch unscrewed above the intake manifold. the noise was from the gasket flapping around during higher boost. the same way a blade of grass or piece of paper makes a whistle noise when you blow on it between your lips. i looked up the torque specs for those bolts which is 18lb/ft. went for a test drive and alakazzam!!! noise gone and better throttle response and pulls a little bit harder now.

Nice work! Glad the leak tester worked out for ya :tu:

Good tool to keep around whenever you own a forced induction vehicle.