Repair Topics / Vacuum Leaks

• How to check for engine vacuum leaks
• My car is making a whistling sound
• Why does my engine stall?
• Why does the engine stall after replacing the battery?
• Why is my engine running rough?
• Why does my engine have low power output?
• How an idle air controller works
• How to check compression
• How to retrieve trouble codes
• How to test fuel delivery system
• Engine cranks but wont start
• Engine cranks excessively
• Engine stalls
• Engine vibration
• Engine has excessive smoke
• Engine has lean mixture codes
• Engine idles high
• Engine idles low
• Engine is making excessive noises
• How to tune up your engine
• How does a MAF mass air flow sensor work?
• How to test an oxygen sensor
• Howling noise from car

MORE: Engine vacuum questions

Car Vacuum Leak Problems

Question: 1999 Dodge Ram 1500, mileage: 149,000. I can hear hissing noises from it when I blip the throttle slightly which leads me to believe there is a nasty air leak somewhere. What is likely to be the problem on this (Although there could be may reasons.)? I can't find any technical info on the dual ram. I'd like to be able to check and make sure that all the lines are correct placed, and find damaged faulty components if any.

Answer:   Toady's car engine intake manifold is complex including idle air control motor, tuned intake runners, split plenum etc. Intake manifold air velocity noise is normal. To check for a intake leaks scan PCM for sensor values that are operating out of range. Ex: If you have a trouble code mass air flow sensor and a oxygen sensor at the same time you could have a vacuum leak.

Question:   2001 Ford Escort, mileage: 111,000.  I have a vacuum leak coming from under my dashboard.  Where my brake goes thru the firewall into the booster.  What could be causing the loss in pressure when I apply my brakes?

Question: 1999 Ford Explorer, mileage: 107,000.  I have noticed a hissing sound coming from the fuel pressure regulator port located on the fitting where several vacuum hoses connect to the intake manifold.  This port has only a cap on it, I replaced the cap but the hissing is still there.  I can push on the cap and the hissing is reduced but what can cause this?

Answer:   Check the vacuum port hoses behind the port with the cap, repair as needed.

Repair Topics / Vacuum Leaks

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