Hey fellas i got a 99 f150 4.6.Just the first time i crank it in the mornings and i turn my a/c or heat on it make a grinding noise in the engine.I think it might be the fan clutch but i wont some other opinions thx alot.

 

Does it only happen when you turn the heat or A/C on?

Offhand, can't think of anything that meets both criteria in the engine. Was thinking about the A/C compressor - but that shouldn't be engaged with the heat, unless you're in defrost mode.

The radiator fan clutch should make the noise regardless.

The HVAC fan might be squalling - but you should be able to localize the noise away from the engine.

Hmm, have to think on this some more.....

 

I got to pay attention i think it is just the ac and defrost ill have to check in the morning.Yea it kinna sounds more toward the passenger side of the engine which it would be the compressor.It blows real cold and everything works good it just grinds that one time then its ok for rest of day.I tried to turn it off and turn it back on it didnt do it.

 

wde3477, the a/c compressor comes on in almost any position of the climate control. It acts as a dehumidifier. I was thinking the a/c clutch or compressor also.

 

Yea i hope its the clutch instead of compressor.Is there any way to test it or see which one.I would lean toward the cluch since i really dont have problems with ac compressor but correct me if im wrong.

 

That's really a tough call. The clutch could be going bad and slipping, or the compressor may be slowly seizing up causing the clutch to slip. Look at the compressor with the a/c off when the truck is running and note the part that isn't spinning. When the truck is cold (which is when you say it happens) and with the truck NOT running grab the non spinning part and spin it. It won't be really easy as you will be pumping the compressor by hand. You should be able to feel if the compressor is pumping right or if it feels like it's sticking. If you only have to change the clutch then you don't have to discharge the a/c system, saving you money. At least I think so, that's how it was on the vehicles I've worked on but haven't worked on anything that new.

 

Yea ill try it in the morning.When i can see ill prolly have to get under it cause the compressor is about 2inches from the fan might tingle a lil if my big hand gets in there.But atleast the fan isnt metal like it used to be.Im the type if somthing is goin wrong i would like to get it fixed.I just hope it isnt the compressor cause i dont fool with acs has to much to them and i dont have the tools.You have been a big help sean thx.