Hi Everyone,

 

I tried searching for this topic but with no luck, hopefully some of you might give some insights.

 

So my skoda fabia 1.4, 2006 (fuel - petrol) broke about 3 weeks ago, which turned out to be 2 ignition coils that needed to be changed. I changed those and also changed all 4 spark plugs. the car seems to run smoothly now but...

 

Usually before I changed the coils the rpm when stationary stayed at about 800... now when the engine warms up after a small trip the rpm stay at about 700-750 (the rpm at this point are also stable)... also I noticed that when I'm breaking before an intersection and I go into neutral I see the rpm drop to 700-800 (which seems to be normal) but then right before I stop the rpm dip to about 600 and comes back quickly. And this is quite annoying since I think this did not happen before.

 

This happens irregardless whether or not I'm pressing the clutch.

 

Has anyone noticed something similar? what are your rpm in these situations? is this even a problem or am I just paranoid?

I suspect a vacuum leak from the brake servo line, unmetered air is being sucked in leaning the mixture and dropping the RPM while you brake.

9 hours ago, sepulchrave said:

I suspect a vacuum leak from the brake servo line, unmetered air is being sucked in leaning the mixture and dropping the RPM while you brake.

 

Hey, thanks a lot for your input. Would this leak also produce a unusual sound while braking? because in the morning when the engine is still cool and I begin to drive I hear a noticeable sound when braking... which dissapears after some 10-15 mins...