rbr0wn

Hello there... I've been having some problems with my 2016 F150 2.7 EB, specifically with the car "vibrating" when the AC is on. It is still under warranty, so I decided to drop it off and the dealer had it for a day. When I got it back, the checkout paper said something along the lines of "could not duplicate issue" and when I asked, the lady said that because the system was reflashed, it probably was fixed by the time they went to diagnose the problem. It was the end of the day, I wanted to get home from work, so I said ok, and I would bring it back if I had any issues. Sure enough, at the stop sign out of the dealership, 30 seconds after leaving, I feel the slight vibration. It almost feels like the engine is trying to autostop, but isn't allowing itself to actually turn off. It almost always happens with the AutoStart/Stop cannot activate icon is on the dash and is only noticeable at stops. And it is 100% connected to the AC.

Now because I work long hours during the week, getting my truck to and from the dealer is a little bit of an ordeal. I need to drop it off before they open, which means I can't sit and explain it, and then I need someone to drop me off at the dealer before they close for the day...

So I have a USB OBD2 and a copy of OBD Auto Doctor on my laptop, so I decided to do a little investigating on my own. I took it for a spin around the block monitoring RPMs and nothing particular made any real blips on the graphs that matched up with the vibrations. Perplexed, I backed into a parking spot and started to just play around with the different sensors. I decided to watch the Absolute Engine Load % sensor, and I saw something strange:



The cyclic on and off of almost 10% load.

So I turned the AC off:



Then back on again:



I pop the hood and watch around the compressor area and:


The tensioner is clicking on and off in exact sequence of the load graph. Watching the block overall, the sudden change in load does cause slight vibrations each time. I would bet sometimes more than others, the load change causes more vibrations and those are the ones that I can physically detect from inside the truck.

Now I've seen crazier things, but I find it very hard to believe that the AC compressor was designed to be cycled on and off regularly in 5 second increments. Can someone please validate that this is in fact an issue before I go into the Ford dealership and demand them actually look into the issue and present them with all of the evidence?

Thanks for any help

2k12 FX2

Check out this thread. There are some AC issues in the 2016's. May not be much to it, but its something


https://www.f150forum.com/f118/2016-...nality-353622/

rbr0wn

Thanks, looks somewhat related. At least there's something to point to when I go be an a-hole to the dealer.

The proposed temporary solution to that problem is a reset of the PCM, which given the exact timing between each cycle leads me to believe it is a computer/electrical issue rather than a mechanical issue and a PCM reset may fix that even if it isn't the same issue.

2k12 FX2

Do you have forscan? Very easy to do that yourself.

rbr0wn

No I don't. I was under the assumption that I needed a special type of/modified OBD2 Sensor to do any writing, so I have held off on it just out of laziness/being a cheap bastard. Mine is a cheap Ebay Bluetooth Elm327.

RL1990

You're leaving out some information needed to help you. What is the ambient air temperature? Do you have manual or automatic system? What are your settings? Is it blowing cold air?

I don't have the 2.7 but the compressor does cycle frequently in certain conditions. But it will run constantly with no cycling in other conditions. The compressor cycles based on pressure and evaporator temperature. If you are set on recirculate and low fan speed the evaporator temperature will get low enough (36/37 degrees seems to be the limit) for the compressor to cycle off. If the ambient temperature is high and it is set on fresh air and the fan speed is high the compressor will run constantly; because the evaporator temperature never gets cold enough to cycle the compressor off.

If the pressure is to low or high the compressor will cycle frequently from signals from the low and high pressure sensors. This is usually caused by under filled or over filled with refrigerant. High pressure could also be caused by high ambient temperature. Either way high pressure will trigger the cooling fans to run on high speed.

If the air conditioner can drop the temperature of the OUTSIDE air about 40 degrees it's working very good. So if the air coming out the vent is 50 degrees and its 90 outside your truck is doing good. This is also with idle speed raised to 1,500 RPMs. Also why you should always use recirculate on sunny warm days. It should have no problem getting the evaporator as cold as it is allowed cooling the recirculated cabin air.

rbr0wn

90 deg F + (South East Texas), but the vibrating happens at all temperatures.

Manual AC/no digital display. *****.

A/C on, temperature set to max cold, but the vibrating happens whenever the compressor is on. Haven't had a chance to see if the intermittent load is at all settings.

Yes, but I have recently had the thought that it didn't feel as cold as it once was. Could just be my recent moving to Texas though. When I first got the truck I remember having to turn it down due to it getting too cold, and now it seems that it can't get cold fast enough. But after the car cools down, it can hold a cool temperature quite easily.


Well ambient was definitely high, and I don't believe recycle was on. I rarely use recycle.

Yes, I wouldn't be surprised if I have a small leak in the AC, given that cyclic compressor kicking on and off is linked to low refrigerant and it doesn't seem as cold as it once was.

Don't have a a thermometer to measure it with, but I may go pick one up.

So question, lets say that I have a leaky o-ring or something. Recharging only helps for so long. It is under warranty, so they should have to fix it. But what if they don't. What if they just recharge the AC and say that it was never filled from the beginning, and by the time it leaks again, I'm out of warranty. Am I now responsible to pay to fix it? Even if the issue was brought up during the warranty period? Sorry, I've never had a new car so the warranty thing is new to me and so far I'm not that impressed (3/3 things it was brought in for were not fixed this past time). I don't mind getting my hands dirty, but if I have to break out my wallet when it is their issue, I'm not happy.

Thanks for your help.

RL1990

You say you have it set to max cold. Max A/C will automatically turn on recirculate. Also the truck, even with a manual system, automatically turns on recirculate when outside temperature reaches 75 degrees. Two things you can do to check your system. Put it on max a/c and feel the low pressure line. It should be cold and wet. If you live in a humid climate run it on fresh air, full cold, and medium fan speed. After it runs awhile condensate should be running out under the truck. Or you can look at the condensate drain on the passenger side firewall for water coming out. You can also try this. On a hot day set the system to fresh air, max fan speed and full cold (not max a/c) at normal operating temperature and the compressor should not cycle as frequently.

If has a leak the system is factory filled with a dye that shows up with a UV light.

Don't worry about the compressor cycling as a judge of performance. The compressor cycles when the evaporator gets cold enough. Remember the truck's system is designed to handle 90+ temps, high humidity and full load of passengers inside all at the same time. If the truck has been running awhile and it's on recirc with a low fan speed it will have no problem getting the evaporator cold even on a 90+ day. If the compressor kept running the evaporator will ice over, this is why it cycles off. As soon as the temp goes up a few degrees it cycles back on. Also the tensioner moving when the compressor cycles is normal, mine does it too. Get a vent temperature gauge to check your temperatures.

rbr0wn

I appreciate the help. I'll stop by somewhere to get a temperature gauge tomorrow and will report back with any findings.

Also, I don't use the "MAX A/C" setting, I simply move the dial all of the way to the left, and turn the fan to what I want it at. I have a pet peeve about air blowing on me so I don't necessarily
prefer the AC blasting if it doesn't need to be.

Bubbabiker

I have the same symptoms as the OP, rough idle only with the AC on, and it's rhythmic with the cycling of the AC compressor. With the scan tool I watched the RPM's fall to around 550 and the rough idle starts, above 600 RPM's the roughness stops. No misfires and the monitors are in the green. Watched the timing constantly go from +4 to -11 during idle but I heard this is normal for the EB.

Another member had the exact same issue and the dealer replaced the coil, spark plug and finally the injector. The injector supposedly fixed the rough idle issue.