How To Check For Air Leaks

[matt76]

i have a 98 gmc sierra with 198,000 miles, the check engine light has been on for months.

i forget the code number but it basically saying i have an air leake.

gas milage is horrible, stumbles when i accelerate.

i tuned her up last winter, new fuel pump last winter, my third fuel pump.

whats the best way to check for air leaks?

[Draenor]

Air leak in what, EVAP,EGR,Vacuum?

[matt76]

Air leak in what, EVAP,EGR,Vacuum?

 

sorry, i meant vacum leak and i don't know where it is.

 

is there anything i can do to pinpoint the location?

[cmoore74]

We used to use WD-40. Basically with the engine at idle you spray some WD-40 at various locations you might have a vacuum leak. If the engine stumbles when you spray a certain location that's where the vacuum leak is.

[Wingnut]

We used to use WD-40. Basically with the engine at idle you spray some WD-40 at various locations you might have a vacuum leak. If the engine stumbles when you spray a certain location that's where the vacuum leak is.

 

Might want to use Sea Foam instead...It's good for the internals. WD-40 can dry out gaskets and whatnot.

 

Just my uninformed opinion though

[cmoore74]

We used to use WD-40. Basically with the engine at idle you spray some WD-40 at various locations you might have a vacuum leak. If the engine stumbles when you spray a certain location that's where the vacuum leak is.

 

Might want to use Sea Foam instead...It's good for the internals. WD-40 can dry out gaskets and whatnot.

 

Just my uninformed opinion though

 

 

Good point. Used to use this method before they had sea-foam in a spray can or maybe we just didn't know you could get it in aerosol form.

[matt76]

thanks for the help, i'll try it out.

i'll post a new topic on my findings.