I reasantly installed a wet nitrouse kit on my truck. After the install we headed for the track and on the way there I started to hear a whistleing or squicking sound coming from my engine bay, I thought maybe it's pulley going bad and didn't make anything of it. Well I ran it and it ran pretty good for a 100 shot. Any way I took it over to autozone and the guy there kind of helped me track down the noise and he came to the conclusion that it was one of my idler pulley's well I bought it and put in on. Same thing nothing changed, well me and my buddies went into further investigation and I found that when I pull the oil dip stick out while the engine is running the noise stops. I push the dip stick back in and it starts up again and also when I take it out theres alot of vacume in the dip stick. Any Idea why this is happening ? I've done a little research and found that some other guys with similar problems noticed the noise after changing spark plugs. Well know I wonder is it a coinsidance, because I too changed my spark plugs for the NGK TR6's for the nitrous setup. If anybody can help I'de apriciate it. Thanks in advance. . .

 

nitrous kit happen to be a plate kit?

 

My engine used to whistle when I had a fixed orifice PCV valve and an AMW oil catch can. I swapped the PCV for the old style spring and plunger and the whistling stopped.

 

Yes it is a plate kit from nitrous outlet.

 

Vacuum leak.......

 

hey man whats up?ide run some breathers on it ,maybe that would help.delete the pcv,i run a k-n breather on my oil cap as well.

 

Would it be cause of the little hole that the throttle body has above the flap? The spacer doesnt have it.

 

That sounds like it.

The little hole the TB has above the TP is the supply of metered air into the engine when the Intake is vacuuming air from the crankcase through the PCV valve in the driver's valve cover. If you starve the crankcase of air then the PCV system will create a vacuum in the crankcase and can cause it to suck in air from any gasket or source that is not super tight. Since it is sucking air through a tight hole it is probably causing the whistle.

The plate will need a hole to match the one on the TB or you will need to block the nipple on the back side of the TB and vent the passenger side valve cover to the atmosphere through a filter so as not to suck dirt into the crankcase.

If you vent the passenger valve cover to the atmosphere and you are running a MAF it will change the tune a little and lean it out some as you will be sucking un-metered air into the intake under vacuum through the pcv valve. You might also find that blow-by may push a little oil out.

You could also block the PCV nipple on the driver's side and vent both valve covers to the atmosphere through filters. This should cure the tune going lean due to un-metered air entering the intake. You may again find oil being pushed out by blow-by.

 

thanks so do you think I might of got the Wrong plate kit? Or what would be the reason that the nitrous plate don't have that little hole?