'05 FX4 Rough Idle, Grinding Feeling and AC Whine
08-04-2014, 03:11 PM
#1
'05 FX4 Rough Idle, Grinding Feeling and AC Whine
I have an 05' FX4 5.4L with 93K on it. Over the last couple months it's developed a sort of grinding feeling when you're on the accelerator. There's no metal on metal grinding noises or anything except for a slight whine that sounds like it's coming from the rear wheel when I'm decelerating to something like a stop sign. There are also a couple other symptoms that's it's doing right now too. I get a pretty rough idle at stop lights (in drive but sitting still for 30+ second) and also the AC pump has developed a little bit of a squeal in these hot summer months. I don't know if anything or all these things are interrelated.
I just changed my plugs a couple weeks ago which fixed a bunch of other issues and that made a world of difference while driving but that rough idle and grinding feeling are still present. I also just cleaned out my throttle body- the right way by taking it all the way off and with proper throttle body cleaner. That didn't change much either.
Also, turning the A/C off doesn't change anything except the compressor noise stops and you can feel it stop. This grind/rattle thing is still present.
I'm wondering if it's a wheel bearing going? Although, I can't really feel it when coasting or on the breaks. It's not the brakes I know that. I'm not getting any codes or CEL's and I've reset the throttle recently too. I'm driving me nuts! Especially since just changing the plugs I got all the big problems out of the way this little thing really stands out.
I just changed my plugs a couple weeks ago which fixed a bunch of other issues and that made a world of difference while driving but that rough idle and grinding feeling are still present. I also just cleaned out my throttle body- the right way by taking it all the way off and with proper throttle body cleaner. That didn't change much either.
Also, turning the A/C off doesn't change anything except the compressor noise stops and you can feel it stop. This grind/rattle thing is still present.
I'm wondering if it's a wheel bearing going? Although, I can't really feel it when coasting or on the breaks. It's not the brakes I know that. I'm not getting any codes or CEL's and I've reset the throttle recently too. I'm driving me nuts! Especially since just changing the plugs I got all the big problems out of the way this little thing really stands out.
08-04-2014, 04:13 PM
#2
Senior Member
I have an 05' FX4 5.4L with 93K on it. Over the last couple months it's developed a sort of grinding feeling when you're on the accelerator. There's no metal on metal grinding noises or anything except for a slight whine that sounds like it's coming from the rear wheel when I'm decelerating to something like a stop sign. There are also a couple other symptoms that's it's doing right now too. I get a pretty rough idle at stop lights (in drive but sitting still for 30+ second) and also the AC pump has developed a little bit of a squeal in these hot summer months. I don't know if anything or all these things are interrelated.
I just changed my plugs a couple weeks ago which fixed a bunch of other issues and that made a world of difference while driving but that rough idle and grinding feeling are still present. I also just cleaned out my throttle body- the right way by taking it all the way off and with proper throttle body cleaner. That didn't change much either.
Also, turning the A/C off doesn't change anything except the compressor noise stops and you can feel it stop. This grind/rattle thing is still present.
I'm wondering if it's a wheel bearing going? Although, I can't really feel it when coasting or on the breaks. It's not the brakes I know that. I'm not getting any codes or CEL's and I've reset the throttle recently too. I'm driving me nuts! Especially since just changing the plugs I got all the big problems out of the way this little thing really stands out.
I just changed my plugs a couple weeks ago which fixed a bunch of other issues and that made a world of difference while driving but that rough idle and grinding feeling are still present. I also just cleaned out my throttle body- the right way by taking it all the way off and with proper throttle body cleaner. That didn't change much either.
Also, turning the A/C off doesn't change anything except the compressor noise stops and you can feel it stop. This grind/rattle thing is still present.
I'm wondering if it's a wheel bearing going? Although, I can't really feel it when coasting or on the breaks. It's not the brakes I know that. I'm not getting any codes or CEL's and I've reset the throttle recently too. I'm driving me nuts! Especially since just changing the plugs I got all the big problems out of the way this little thing really stands out.
08-04-2014, 04:27 PM
#4
Thanks for the quick replies guys!
After typing all that I went out and checked it a little again. The rough idle seems to hit right after the AC compressor turns off. It's like all the sudden the engine doesn't have anything to apply power to so it just shakes until the RPMs come down low enough. It really does seem likes it's working extra hard to run that A/C compressor when I first start the thing. It whines like crazy.
The grinding/rough feeling seems to happen when decelerating too and the truck shifts down. Its the same feeling as if you take your overdrive off or if your in 4WD but not quite as drastic.
Where should I check for vacuum leaks and whats the best way to do that?
After typing all that I went out and checked it a little again. The rough idle seems to hit right after the AC compressor turns off. It's like all the sudden the engine doesn't have anything to apply power to so it just shakes until the RPMs come down low enough. It really does seem likes it's working extra hard to run that A/C compressor when I first start the thing. It whines like crazy.
The grinding/rough feeling seems to happen when decelerating too and the truck shifts down. Its the same feeling as if you take your overdrive off or if your in 4WD but not quite as drastic.
Where should I check for vacuum leaks and whats the best way to do that?
08-04-2014, 08:19 PM
#5
Senior Member
This thread has a lot of good information:
http://m.f150online.com/forums/showt...599&styleid=17
As for the ac, you could be low on freon, or just need a new belt.
When you cleaned the throttle body, did you also clean the mass airflow sensor?
http://m.f150online.com/forums/showt...599&styleid=17
As for the ac, you could be low on freon, or just need a new belt.
When you cleaned the throttle body, did you also clean the mass airflow sensor?
08-05-2014, 09:16 AM
#6
I checked all the vacuum lines last night and everything looked good.
The MAF was in pristine shape when I did the throttle body and I didn't have any MAF cleaner so I didn't want to mess anything up.
I noticed last night that the rough feeling only comes when the AC is on and I'm decelerating. Essentially when the RPMs go from on throttle of ~1500 to off throttle of about ~600. I think it's when the compressor starts back up after being on the gas.
All this stuff seems to be center around when the A/C clutch is engaged and when it's not.
The MAF was in pristine shape when I did the throttle body and I didn't have any MAF cleaner so I didn't want to mess anything up.
I noticed last night that the rough feeling only comes when the AC is on and I'm decelerating. Essentially when the RPMs go from on throttle of ~1500 to off throttle of about ~600. I think it's when the compressor starts back up after being on the gas.
All this stuff seems to be center around when the A/C clutch is engaged and when it's not.
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08-05-2014, 11:49 AM
#8