what is a "large vaccuum leak"?

Question

My check engine light came on. Went to a local parts shop to get the diagnosis thingy hooked up to get a reading. When all was said and done, the guy said I had a "large vaccuum leak". What is this and is it expensive to replace---going to a small business mechanic versus going to a dealership shop? What kind of expense should I be preparing for?

My car is a 2001 Mazda 626

thanks for any help!!

Answer 1

A gross vacuum leak will cause a P0455 code to be set. This could be as simple as a loose gas cap or may be much more involved. The best way to tell is take it in for an EVAP system check. The dealer will have a machine that pumps smoke into the EVAP system to pinpoint where the leak is. Before taking it in for repair, make sure the gas cap is tight, or you have not put fuel in the car with the engine running. These are the number one causes for a gross vacuum leak. My dealership charges a 74.95 diagnostic fee, others may be different, but you can feel confident in knowing that the problem will be found when using a competent technician.

Answer 2

Many things in a car are operated by vacuum - the brake booster, the cabin air flow direction doors, just to mention a couple. This vacuum is produced by the engine air intake system, and is conducted to places where it is needed by a system of small hoses. A small hole (leak) in one of the hoses will affect the vacuum system, but not disable it. A "large" hole (leak) can completely disable all the devices operated by the vacuum system, and also affect the way the engine runs. Any competent mechanic should be able to deal with it, and it shouldn't be too expensive - probably less than $100.

Answer 3

a large vacuum leak is bigger than a small vacuum leak. Start off by checking all of your hoses for tears or lose fittings. Most likely, this shouldn't be an expensive repair. You will also get better performance when it's fixed.

Answer 4

some switches and other devices are operated by vaccum . if there is a a leak in the vaccum line it will not have enough suction to operate properly.if the leak is in a hose you can hear it making most times ..you can usually replace the hose for less than a dollar.most auto parts dealers such as auto zone will usually or napa will have a "good ol' boy" that will walk to your car and point out something as simple as this,

Answer 5

If it has a large vacuum leak you will hear a hissing noise coming from the engine compartment somewhere, the engine will likely idle high. did they happen to tell you what code they got out of it?? that would help a little more too

Answer 6

The Ford tech is right on the money. I would make sure the gas cap is on tight and have the light reset by the parts shop. If it doesnt come back on your in luck, otherwise take it in and have it checked. (9.9 out of 10 are always the gas cap!!)

Answer 7

Large vacum leaks refer to "manifold vacum". The 3 main areas are 1 the intake manifold 2 the vacum line to the brake booster 3 the vacum line to the PCV valve.

The only one that is expensive is the intake manifold gaskets, the rest can be fixed by replacing the vacum line.

Answer 8

hi, a big vaccum leak offen means that you forgot to tighten your gas cap and it will set an evap code, but it could be a vaccum line that is broken off too so the best thing to do is to go to a dealer and have them check it out. it cost a bit more BUT they know your car and they offen know right away what it is so it will be cheaper in the long run...

Answer 9

large vaccuum leak huh...probably not an expensive problem at all...just a vaccuum line that has come off or been chewed by a rodent or something...if they try to sell ya a part, ask to see the old one and stay with em to go see it

Answer 10

you can always get a second opinion and take it to another shop. sounds like it could be a little expensive.I am not into car made over seas, they are hard to find parts for and you better have a big bank book when they brake down. Good luck.