I've been hearing a hissing noise and I have been getting code p0171 , and I believe its a vaccum leak somewhere... How can I test it.... ? Thanks

 

smoke machine

or u can spray sterter fluid at point of the vacuum lines while engines on. if it starts chugging theres a leak there

 

My mom has a smoke machine she puts out her house on halloween....I'm gonna see if I can use it... Lol

Just hope its not a cracked intake mani :'(

 

its not a cracked intake manifold and the best way to look for a vaccum leak is doing a boost leak check google how to do it

GDS

 

I believe there is a how to for LNF's on here... Is it the same thing for LSJ's?

 

yea pretty much

GDS

 

Starter fluid method is quickest. But I usually prefer to just use my 2 ears

 

It's probaly by the injectors. Spray some throttle body cleaner around the injectors.

 

I like the carb spray way to test it

 

I'm gonna cry of happiness once I find the leak.......
So I can spray around injectors safely without blowing up?

 

Yeah have the car running and with the little extended tune it has spray closely so you know around where it's coming from. If you have leak it should rev a little

 

So it will rev once it gets in the leak...? will it go past 7k rpms??? Jk jk I have to do it asap... If its leaking around there does it mean my injector rings are bad or head gasket?

 

If you're spraying right into where the injector seals are then it's the orings that are bad. If you don't find a leak through there spray on all the opening areas of the manifold also

 

No it won't do a huge rev lol

 

Cobalt ss 06 100k miles for sale
Runs like new
Tc rims with lots of meat on tires
Professionally smooth and painted dash and trim
Smoked lights
New catalyc converter
New power steering assembly
Ttr trans mounts
Wrapped roof
15k obo or trade for an escalade

 

Lol 100k damn haha

 

Boost leak test with soapy water. That would be the preferred method. DO NOT use carb cleaner on a hot engine, lol, unless you like potential fires. Crack open the propane and run it across the potential leak areas. The rpm jump won't be a lot, just enough to compensate the unmetered air entering the leaking area.

 

Oh yeah lol not when the engine is hot...I did it when the engine was cold and not even warm yet..

 

there are only 2 answers in here worth a ****

GDS

 

I can definately hear the buzzing sound a little louder.......... And didn't see any leaks around the iinjectors ..but it was at night... Hope I get off work early so I can start looking into the intake many area.......

and I used soapy water

 

peanut butter

 

Did you spray tb cleaner around the injectors with the car running? You are not going to be able to see a leak with your eyes, just by looking at the injectors.

 

I hear a buzzy hissy sound when im driving too. Idk whats leaking i replaced a few hoses that looked cracked up, sprayed tb in a few spits, tightened down my exhaust mani as good as i could... Guess i could check the inectors

wer'e are haz teh embassys on our controls

 

I used soapy water as suggested by a member since I had no tb cleaner but it was dark soidk... Lol ill check today... I'm thinking about trading this bitch in

 

Used carb cleaner with no luck......