2003 GMC Envoy Repair Question
Topics covered: Smoke, Auto parts, Check engine light.
Mileage: 14,500 miles.
Mileage: 14,500 miles.
Asked on March 20, 2012
Vacuum fault. replaced gas cap without results. where do i start looking for a vacuum leak?wlewan60@aol.com
Check engine light is on and the meter says that it's a vacuum leak. I replaced the gas cap but that didn't correct the problem. I looked online trying to find a schematic for the vacuum system and haven't yet found it. What would be your suggestion?
Asked by lewanAnswer
Replied on March 20, 2012
Finding a leak in this system is almost impossible without a smoke machine. You might be able to find one at an auto parts store that borrows or rents tools. It injects a white non-toxic smoke at 2 psi, then you search for where it's seeping out. The alternative is to hope to find something real obvious like a rusted-off hose clamp or dry-rotted hose. Other possibilities include a leaking purge valve or charcoal canister. There's nothing visual you can see with those types of leaks.