Steve-O-08

iTrader: (5)

Originally posted in the GM Engine & Exhaust Performance section:

Vacuum at Dipstick??

My truck has been making a slight whistling noise occasionally on acceleration and I can't seem to pin point the source. It does not sound like a belt or bearing. I was looking around under the hood today and it seems like I have full engine vacuum at the oil dipstick. I don't ever remember it before. Anyone experienced this before? could this be the source of my noise?


Out2win had said:
Its from the Nitrous plate. We installed 3 nitrous kits on 3 different trucks and they all did that. 2 kits were Nitrous Outlet and the other was a Harris Speedworks. 2 of the trucks just put a breather where the dipstick goes and the "whistle" went away.

Anyone experience the same condition with a plate???

BlackGMC

iTrader: (31)

Well imo you should have vacuum at the dipstick because your pvc system is pulling a vacuum on the crankcase.

Dezert1500

iTrader: (11)

If your plate blocks your TB vent then you'll have vacuum issues. Or sounds like your pulling vacuum post throttle body now because of the plate. Just plug the port on the intake manifold and run the passenger breather to the intake tube pre-throttle body.

SRTKLLR

iTrader: (1)

I get that whistling noise at certain throttle angles too. I think it started after the nitrous plate install. Sounds like I have a blower sometimes, lol.

Steve-O-08

iTrader: (5)

I checked the passage on the plate when I installed it, didn't seem like it was blocking anything. Going to check it out today.

Yeah That's seems like the same noise I was experiencing. Trans is making noise too, have some inspecting to do today.

OUT2WIN

iTrader: (1)

Exactly, the kits I installed do not have the vent on the plate to match up with the TB. When I called Nitrous Outlet about it (thinking maybe I got a kit for a car?) they didnt seem to understand what I was explaining to them and my patience that day was running on low so I just gave up on it and put a breather on the dipstick tube.