Grill Shutters..why, how, and when

[Roger Blose]

I have a 2018 GT with the active grill shutters. Does anyone know when these close up and re-open? I have started my car in winter cold days and they are open so they do not aid in fast warm ups. On the highway they are supposed to close off for aero but at what speed does this happen, what temperature will cause them to open up, and what sensors are controlling this hardware? I do know that the PP1 and PP2 cars do not have these parts at all.

Sponsored

 

[Deleted member 35644]

In regard to fast warmups, what goes on in front of the radiator is irrelevant until your thermostat opens, which should be around 180 degrees. The quickest way to heat the engine to 180 degrees is to drive it, versus waiting for it to warm up at idle. Shutters won't help much in that regard unless you're dealing with some seriously cold temperatures that bleed more heat than the engine can generate. (This happened to me once in Wyoming - I parked my fully-warmed-up Civic Si facing into the wind while idling, and when I returned to the car, the temperature gauge was pointed to Cold). By the time your coolant is hot enough to open the thermostat and allow the radiator to take part in the cooling process, you have plenty of heat for the interior.

I've read that they're programmed to open at certain angles according to coolant temps. If the engine is adequately cooled, they'll close, or partially close at highway speeds as an aerodynamic aide. Logic says that wheel speed, A/C status, and coolant temps drive the 'shutter decisions'. They should be open any time the A/C is engaged, because the fan will be running.

 

[Roger Blose]

Just watched Motorweek last night and they had a segment on grill shutters. They are all about aero fuel economy improvements and do work only at high speed, ( closed), unless cooling is called for. They had a video showing them in action. The Rock Auto guy said that they do go bad with age and cars may overheat. Pat Goss claimed to have had several F-150s come into his shop for replacements which Rock Auto does sell. Hopefully these units will not create headaches for us Mustang owners as our cars age.

 

[Deleted member 35644]

Before long, I will be removing the shutters from my Focus and zip-tying the motor to something secure. Not going to wait for them to fail before I resolve the issue.

 

[FreePenguin]

I don’t really know why my car was blessed with not having them from factory. Notta nothing.

 

[Andrew@Lethal]

I have a 2018 GT with the active grill shutters. Does anyone know when these close up and re-open? I have started my car in winter cold days and they are open so they do not aid in fast warm ups. On the highway they are supposed to close off for aero but at what speed does this happen, what temperature will cause them to open up, and what sensors are controlling this hardware? I do know that the PP1 and PP2 cars do not have these parts at all.

I always deleted the grille shutters on all of my car. I prefer the constant heat extraction and cooling benefits.

 

[ice445]

I would imagine the shutters do a good job in the winter of protecting the rad from errant rocks and such, so I suppose that's nice. Most of the time in the summer they'll always be open, few people are driving on the highway with the A/C off, lol.

 

[Deleted member 35644]

They may even close or partially close at highway speeds with the A/C on. Cooling fans in some cars won't come on above a certain speed. Found this out in the service manual for my '85 Laser when I was trying to get the cooling fan issue resolved.

Sponsored