Hello all,

Long story short, I know our radiator and condenser has two fans, and they operate at a low and high speed depending on outside temp and if AC is on or off.

I am sick of the on/off cycling of the radiator fans while stopped in drive and idling. It causes vibrations even in the seats; and idle dips to compensate.

This only is happening when radiator fans go into high speed, at low speed with AC on there is no idle dip and no vibration.

Question is, how can I make the car keep the radiator fans on at low speed all the time?

I have k tuner and HDS

New battery
new idler tensioner
new alternator
both new cooling fans
all new mounts OEM

Zero check engine lights, and zero misfires

thanks

 

Try doing an engine mount neutralization to reduce the vibration, also idle relearn procedure.

 

That’s a good thinking. I did do the mount neutralization method when I replaced the mounts.

I am leaning toward a voltage issue. However battery test good, alternator is a reman Denso, and starter is also testing good.

could it be a bad voltage regulator in the alternator I replaced? I don’t have any Check engine lights.

or could it be a bad EDL sensor?

In summary, when the car is at idle and the high speed fans kick on along with the AC compressor, this is causing the idle dip and raise then rhythmic vibration from the cooling fans.

 

How low do the RPM's dip?
Have you cleaned the throttle body and checked the intake boot for cracks?

Check your A/C system too! if the compressor is working harder than it needs to be, then it's putting extra drag on the engine. It could be as simple as it being low on refrigerant causing the issue.