Ford C-Max (2007) keeps dying in 1st gear + weird idle issues - any ideas?​​​​​​​​​​​​​​​​

[sturlabragason@lemmy.world]

Hey! Having some issues with my Ford C-Max (2007) and wanted to ask if anyone's had something similar happen.

So the car starts having trouble when I shift into first and give it a bit of gas - if I give it too little gas it just dies. Now it's started doing the same thing in second gear too. When I first start the car and let it idle, the RPM drops every 10-15 seconds or so (from about 900), but it gets better after running for a while.

Got the yearly checkup recently and everything was fine, but then this started happening. Also got a check engine light that keeps going on and off every other day. It's pretty cold here, like 5 degrees if that matters.

I'm going to take it to a mechanic when I have time but wanted to ask here first if anyone knows what it might be? Maybe the MAF sensor or something with the idle control?

Thanks!​​​​​​​​​​​​​​​​

[grumpyduckling@sh.itjust.works]

There's a few c-max forums you can check. Pulling codes would be helpful. There's a program called forscan for fords that will give you a lot more information than a basic scan tool. I saw a few threads where people had the same issue but no resolution. Just don't fire the parts cannon at it like one guy did.
You could try cleaning the throttle body and doing the relearn procedure.

[jubilationtcornpone@sh.itjust.works]

Lots of things that could cause rough idle.
Vacuum leaks and spark plugs are common culprits.
Dirty/worn spark plugs are often accompanied by unburned fuel or soot in the exhaust.

You'd have to put a vacuum gauge on the intake manifold to check for a vacuum leak.

Beyond that, you'd have to check the diagnostic codes to see if it shows something else amiss.

[onomatopoeia@lemmy.cafe]

That rpm instability at idle is classic vacuum leak symptom.

Pulling codes is almost always step one. Your local parts store will usually pull codes for free. The cheap $10 Bluetooth readers on Amazon, plus the free app "Torque" work well for the price.

[sturlabragason@lemmy.world]

Thanks all, already went by my mechanic once to get the codes, but no engine light or error was present just as i started it then 🥲

Will try again next time I ger the light.