This topic contains 6 replies, has 3 voices, and was last updated by 
Richard Kirshy 2 years, 8 months ago.
-
Topic
-
After turning on the car and letting it idle down I notice that there is a very slight rise in RPM but more noticable change in the engine sound when taking my foot off the brake then immediately returns to normal. If I press the brake down I notice it goes up VERY slightly and the tach doesn’t seem to move, you can only notice it by ear, it’s almost imperceptible but you can notice it better when removing foot. When I hold my foot on the brake for several seconds everything seems normal, the idle only changes when first pressing the brake or letting it go.
Is this normal operation or a vacuum leak? Anywhere I should look first?
Also should I be concerned about it?
-
Replies
-
If you suspect a vacuum leak there are several test methods that can be done if you search youtube you should have no trouble finding them.
Also a check test of your fuel trims can also be a good indicator again a youtube search will be helpful.Thanks I’ll head to youtube and check it out. I don’t currently have a scan tool though, do you have any recommendations for cheap ones around the $20-$40 area?
If you have a smart phone or tablet ..
Along with the TORQUES app will work quite well.
Again how to vids are available on youtube for both.It is normal for fractional engine speed variation when applying or releasing brakes, but if you are suspecting a vacuum leak it’s always good to check.
I was assuming a leak by the change in engine speed alone but I haven’t checked fuel trims yet so that would be my next step then. Thanks guys. I’ll grab one of those BT readers for sure.
See if this is helpful :
https://www.youtube.com/results?search_query=vacuum+leak+check+with+fuel+trims
You must be logged in to reply to this topic.
