Hissing sound from engine area

[Xcobra]

99 corolla here. Every time i turn on the car (maybe 5 mins or so after doing so) I hear a hissing sound coming from right side of the engine (pass. side). Seems like it is in between the pulleys and the firewall. What could it be? Should I just take it to a local mechanic?

EDIT: One thing I have noticed that is very strange is that from having a full tank and driving LESS than 200 miles, I only have a bit over a quarter tank left. Do you guys think the vacuum leak problem has anything to do with it? It is a corolla and efficiency should be way better than that. Opinions?

 

[Brutus04]

Snake! Sorry...

 

[SparkyJJO]

Usually hissing means a vacuum leak. Check the vacuum lines, a rubber fitting could have gotten dry/cracked after 10 years. My old car did that once, annoying but was a cheap fix (cost like 2 bucks for a new rubber elbow).

 

[RU482]

vacuum leak? bearings on belted accessory?

The mechanic's gonna rape you with something so vague

 

[Hyperlite]

Vacuum leak

 

[Bignate603]

Originally posted by: RU482
vacuum leak? bearings on belted accessory?

The mechanic's gonna rape you with something so vague

Not if he's a good one. A vacuum leak you can hear just standing next to the vehicle is going to be easy to find. The OP could probably find it with a stethoscope or even a power towel tube (just put your ear to it and use it to isolate where the sound is coming from).

 

[Jabbernyx]

Originally posted by: Brutus04
Snake! Sorry...

Doh! Beat me to it

 

[Xcobra]

aight...ill try to spot it 2morrow and report back...

 

[SparkyJJO]

Take a piece of tubing and stick one end in your ear, use the other end to probe around, like a stethoscope. May help to find the source a little easier.

 

[Xcobra]

Interesting sparky. What I am trying to figure out is how to spot it. Anyone know what vacuum hoses run on the location mentioned above?

 

[LordMorpheus]

Originally posted by: Xcobra
Interesting sparky. What I am trying to figure out is how to spot it. Anyone know what vacuum hoses run on the location mentioned above?

There are vacuum hoses everywhere.

On my town car I had been hunting a minor vacuum leak for years, I was convinced it was on the firewall behind the engine (I replaced the check valve, it helped, but didn't fix it).

One day I was checking the oil and noticed an unconnected vacuum hose just hanging in the wide open space between the left head and the fender. Like, 12 inches clear on all sides on this unconnected hose. It had just worked itself loose from a vacuum reservoir on the fender. I felt so stupid, but it's also nice to be able to put my foot down without switching my air conditioning to defrost or something.

 

[Squisher]

If you have trouble locating the leak, get some carburetor cleaner (Gumout) in an aerosol can and spray it around the engine bay with the engine running. When you hear the engine pick up in speed a little, it's because it is sucking in the cleaner.

 

[Juddog]

I actually had this same issue; it ended up being a small hose coming loose somehow and falling off, instead of an actual break in one of the hoses.

 

[LTC8K6]

IIRC, propane will make the car idle faster when you get it near a vacuum leak.

 

[Xcobra]

I tried looking for it today but the hissing was just not there. I thought I heard it around the pulleys. Think it might be the idle pulley? Ill keep checking until I hear it again. THanks for the replies

 

[Xcobra]

Ok so I haven't been able to check again since its been raining cats and dogs.

One thing I have noticed that is very strange is that from having a full tank and driving LESS than 200 miles, I only have a bit over a quarter tank left. Do you guys think the vacuum leak problem has anything to do with it? It is a corolla and efficiency should be way better than that. Opinions?