Hello,

I need some help in trying to solve an strange noise that comes from my engine after i have turned the car off.

I have a 2005 1.6 Tdci Focus which is in good condition and is a gem apart from two little things. Firstly is a known problem with the boot lock opening itself, which my local ford dealer has tried fixing 3 times without success.

The other is a strange noise that comes from the engine after the engine has warmed up. After turning the car off getting out, locking it up and walking away the car will make a whirring noise. I have been advised that it is a release valve on the engine which lets out fume/gas build up to ensure a clean engine when you next start up, which is the issue. It is supposed to open and release the build but it appear mine is not opening properly.

My questions are

a - Does this sound correct?

b - What is the valve called?

c - Is it something i need to look into replacing ASAP?

It is embarrassing when you go to a car park and as you walk away your car blows a raspberry at you!!

Any help will be greatly received

Mine makes a noise on engine switch off too

If the engine is particularly warm due to slow traffic, the fan can stay on for up to a minute after turning off the engine.

On switching off after a "normal" run, I get this whirring noise for probably around 30 seconds or so. Its not particularly loud and has never bothered me. I'm not sure what it is, but I think its normal.

Mine makes a noise on engine switch off too

If the engine is particularly warm due to slow traffic, the fan can stay on for up to a minute after turning off the engine.

On switching off after a "normal" run, I get this whirring noise for probably around 30 seconds or so. Its not particularly loud and has never bothered me. I'm not sure what it is, but I think its normal.

It does tend to be the fan, sometimes you may have turned your engine off whilst the thermostat is still open, so the fan continues to run, just gives a quick cool down and then the thermostat closes and allows it to cool naturally. I think most of the heat is just dispersed from underneath, I find most the heat escapes from my wheel arches, but I have this little fan spinning away quite often, it only becomes a problem when the fan is running for longer than 30 seconds every time you switch off the ignition.

I am looking more into the OBDII, but if you have a laptop, it may be worthwhile buying a connection for your car to your computer, you can then monitor live feeds from the sensors, and you can monitor the temperature of the vehicle when the fan is on, and when its off (after switching off the engine) could certainly come in useful for your own diagnostics.

It does tend to be the fan, sometimes you may have turned your engine off whilst the thermostat is still open, so the fan continues to run, just gives a quick cool down and then the thermostat closes and allows it to cool naturally. I think most of the heat is just dispersed from underneath, I find most the heat escapes from my wheel arches, but I have this little fan spinning away quite often, it only becomes a problem when the fan is running for longer than 30 seconds every time you switch off the ignition.

I am looking more into the OBDII, but if you have a laptop, it may be worthwhile buying a connection for your car to your computer, you can then monitor live feeds from the sensors, and you can monitor the temperature of the vehicle when the fan is on, and when its off (after switching off the engine) could certainly come in useful for your own diagnostics.

Problem: There is a 'buzzing' noise after the engine is switched off.

Solution: This is most likely caused by noise from the Inlet Manifold Runner Control (IMRC) actuator being transmitted through the chassis of the car. The solution is to isolate the actuator with rubber washers or similar which will prevent the sound to be transmitted

its not a major issue the boot lock is if it done it on an mot it would fail sounds like something is activating the switch on the dash so either replacing that and see if it helps or get them to check the wiring if they have tried to fix it 3 times and its still faulty then they should continue till they find the issue

Thanks for the help.

I do not beleive the issue is related to the fans as the fans are always very quiet. The noise only last for a maximum of 5 seconds and you can hear very obvious steps in the tone and volume.