Needing some help finding a vacuum leak

[Pizzarolls4]

06 lsj
I have a squeaking sound coming from around bell housing it doesn't start to make the sound until car has somewhat warmed up 160° or so. If I remove oil cap,dipstick, or pcv hose on back of VC the noise stops and starts when removing and replacing these. I have a smoke tester found a couple leaks from brake boosters connections but noise is still present. Any ideas? I'm at a loss here

 

[Pizzarolls4]

06 lsj
I have a squeaking sound coming from around bell housing it doesn't start to make the sound until car has somewhat warmed up 160° or so. If I remove oil cap,dipstick, or pcv hose on back of VC the noise stops and starts when removing and replacing these. I have a smoke tester found a couple leaks from brake boosters connections but noise is still present. Any ideas? I'm at a loss here

Wanted to add EVAP is gone I have the nipple on the TB capped with a rubber vacuum cap and the vacuum hoses are new

 

[Ross]

So do you have air escaping from the dipstick when you pull it out? Is it a plugged PCV valve?

 

[Pizzarolls4]

So do you have air escaping from the dipstick when you pull it out? Is it a plugged PCV valve?

There is a release of air when removing all dipstick,oil cap, or pcv hose on back of VC

 

[Pizzarolls4]

Maybe this is stupid lol but I haven't completely gotten my intercooler system to stop leaking at the connections could this be somehow causing a leak because it's not full of coolant? I currently have it running and disconnected the brake booster completely and capped it off to try to eliminate it being bad

 

[Pizzarolls4]

Oh also pcv valve is new changed it out when I cleaned Intake manifold

 

[Ross]

Sounds like a crankshaft pressure issue... maybe someone who has rebuilt a PCV system can chime in. I think the PCV valve requires pulling the head on our 06 LSJ. I doubt it is the intercooler... because you said the sound stops when you pull the dipstick. Leaky intercooler might mix intake air with coolant, but that isn't part of the PCV system, or the dipstick.
Oh, you changed the PCV valve, well keep digging, as there is more to the system than 1 valve... not that I understand it well...

 

[Pizzarolls4]

So I replaced the rear main when engine was out I slightly knicked around the seal put a dab of rtv to try to remedy it is that a possibility?

 

[Pizzarolls4]

As far as I know there's just the hose that runs from back of valve cover to intake and a pcv valve/check valve near the mating surface of the intake manifold that just pushes in with an o-ring I think that's the whole system

 

[escapepilot]

I think Ross is on the right track. It really does sound like the crankcase is getting pressurized. LSJ…is it possible a hose is routed to the wrong port? With your smoke tester, can you warm the engine and see if the smoke gets sucked into the dipstick or blown away from it or is there too much airflow?

 

[Ross]

The PCV system generally has to deal with the air/exhaust that gets past the piston rings.
Do you have new rings and honed cylinders that are still not seated in? See if the issue goes away once you have broken in the engine.
Do you have a lot of boost? Worn rings? Broken ring? These can all cause more blow by.

 

[Pizzarolls4]

I think Ross is on the right track. It really does sound like the crankcase is getting pressurized. LSJ…is it possible a hose is routed to the wrong port? With your smoke tester, can you warm the engine and see if the smoke gets sucked into the dipstick or blown away from it or is there too much airflow?

Specifically which hose are u thinking may be routed incorrectly?
I can give that a shot tomorrow though this mf lol

 

[Pizzarolls4]

This

 

[Pizzarolls4]

The PCV system generally has to deal with the air/exhaust that gets past the piston rings.
Do you have new rings and honed cylinders that are still not seated in? See if the issue goes away once you have broken in the engine.
Do you have a lot of boost? Worn rings? Broken ring? These can all cause more blow by.

It's a 140k ish motor ran well in the donor I did some refreshing before it was installed timing chain,water pump things of that nature
Stock pulley haven't looked into how much boost I am or aren't making
I haven't done any kind of compression or leak down test

 

[Pizzarolls4]

Also to add I don't have codes that really give me any direction here either I of course get evap codes and a intake temp circuit but I think that's just because like I mentioned my IC system is leaking and iat Temps are getting high

 

[Gtstorey]

Might be time for a cylinder leak down test?

 

[Pizzarolls4]

Thanks guys I'll do a compression and leak down test next

 

[escapepilot]

I forget how the boost bypass works. It was just a thought. We are assuming it’s pressurizing the crankcase but is it possible to cause a crankcase suction? I don’t think so under normal situations but just thinking outside the box and wondering if it’s possible for a vacuum hose to be connected in a way to create a suction on the crankcase and the whistle be sucking air instead of expelling.

 

[Pizzarolls4]

I forget how the boost bypass works. It was just a thought. We are assuming it’s pressurizing the crankcase but is it possible to cause a crankcase suction? I don’t think so under normal situations but just thinking outside the box and wondering if it’s possible for a vacuum hose to be connected in a way to create a suction on the crankcase and the whistle be sucking air instead of expelling.

Are u talking about the bypass valve? I did a simple test although idk if it's accurate I removed it and pushed the plunger in and held my finger over both ports like tht to test it held vacuum

 

[escapepilot]

I had to dig back in my photo archives but it looks like your hoses are hooked up like mine except I just put a breather on the valve cover.