At idle, engine vibration

[Geek2232]

Greetings, all!
Even with the engine warmed up to operating temperature, my 2003 1.8L Mondeo starts shaking when I let it idle.
Up until the rpms return, a little pressure on the gas pedal gets it going again.

It is said that the idling rpm is fine as it stays at 750 and doesn't fluctuate.
Another thing I noticed is that when the engine is not revving (around 1000-1100), all of the lights—cabin, dashboard, and headlights—flicker.

I was worried about the alternator, but the mechanic assured me that everything is OK.

Your assistance is much valued.

[WiseSage]

As the technician was supposed to do, check the battery's condition and the earthing strap underneath the battery.

[ForumGuru]

The rev counter is going to be muffled to compensate for some volatility in the revs, so you can't rely on it.

Find out what the real revs are with the use of an on-board diagnostic information (OBDII) device. Incorporate the Forscan app or software into your purchase.


Follow the on-board diagnostics, a meter connected to the battery, an on-board diagnostics and information system (OBDII) tool, or a meter located in the car's electrical outlets to complete the test. Take every test.

[PixelMaster]

Without a doubt, I concur. In order to help you figure out what's wrong and how to fix it, on-board diagnostics systems are available. They remove all room for uncertainty.

[Geek2232]

I performed several tests in Forscan, alright. Idle rpm ranges from 690 to 705 rpm, spark advancement deviation is low, and both the short-term and long-term fuel trim are good. The short-term trim ranges from -4% to 2%, and the long-term trim is nearly consistent at 10%.

Now my only remaining suspicions are that the vibration could be caused by a faulty engine mount and that the lights could be an electrical issue.


I would be grateful for any suggestions or assistance, despite

[Geek2232]

Hello there, I appreciate you providing that data to me. Once I have the data, I will text you back, but first I need to get an obd2 connector that works with Forscan.

[CodeCrusader]

My 1.4 Fiesta no longer has a terrible idle after I filled up with E5 petrol. Using the higher octane has made my engine run more smoothly at any speed.

[keithmerc220]

Sounds like a lead sparking out or an earth leak, which might cause a short. In the dead of night, inspect the engine leads for the presence of blue sparks earthing.