I just picked up a 2018 5.0 4x4 lariat, with 100k on it, love the truck, but I am noticing a loud "clunk" or "thunk" when starting the truck after sitting overnight, or after it sitting all day when I am at work, I have read EVERY post I can find about this issue and it seems fairly common, HOWEVER, the posts I read state the noise happens on a hot start after driving, and immediately after crank, which is when the videos show the driveshaft turn, mine does it a couple seconds to 5 seconds after the engine starts, mine is definitely from the front of the truck not the back. mine will NOT do it when it is warmed up, or even if I shut it down right after a cold start when it clunks, it will ONLY do it the first start when its been sitting for a while, and never again till the truck sits again. I don't notice the driveshaft moving. the sound from outside the truck is VERY loud, other than that, the truck runs and drives beautifully. I have updated the PCM to the latest build, and that got rid of the shifting issues I had.

all the posts I see are relatively several years old and nothing new about this issue after about 2019. I am determined to find the source because I have a 3mo 3000 mile warranty from the dealer and if It is something bad, I want to get it fixed. If its minor like a starter ill just replace it at work.

Thinking along the lines of possibly a sticking starter Bendix when it sits several hours, possibly the AGS slamming closed (for some reason, I know they close slowly on rams) or transmission issues.

ANY updates on this issue at all? haven't seen anything about newer trucks with this issue, and if every truck did it as loud as mine, EVERYONE would be complaining to their dealers as its far from subtle.

Thanks everyone. Love my new truck aside from this awful, loud clunk.

 

New member here. I have a 2019 5.0 with 82k miles on it now. I live in the frozen north and when it's usually below 15 degrees F my truck will do a funny rattle noise about 3-5 seconds after start and for 2-4 seconds. I have recently changed oil ( motorcraft filter/synthetic blend 5w-20 with a full quart of Lucas synthetic oil additive). I thought it was the timing chain tensioners going bad and oil leaking down so I added the Lucas thinking that would help for a little while. I have had a P0012 ("A" camshaft position Timing Over-retarded bank 1) before and after oil change I haven't had it for awhile. I am trying to attach the video I took today with the noise and it didn't last very long this time. When it's colder I goes a few seconds longer. It's an mp4 and I'm trying to convert it.

 

A/C compressor, mines been doing it occasionally for years.

 

Does your A/C compressor sound like this?

 

Mine clunks sometimes on cold startup. I've never heard it do it on warm startup. I don't worry about it.

 

Same. Mine does it sometimes also.

 

Please start a separate thread when you have a different issue as this thread is the result... people providing answers to separate issues without all of the responses being clear on to whom they are responding.

 

I figured out what was causing my clunk for my particular issue, I started a new thread in case it would help anyone out, this thread could probably be closed I imagine. New is titled “read if you have startup clunk”

 

nice of you to tell us????

 

I figured it would be easier for anyone curious to check my new post as I explain what my issue is. It’s completely unrelated to the startup clunk that a lot of people hear due to the drive shaft engaging a bit, in a nut shell my drivers side intake runners are sticking in the “rest” position after a cold soak and then when the vacuum builds up high enough to “unstick” them, they actuate so fast that the actuator rod slams into the stopper on the intake very hard making a very loud thunk noise. Only does it after sitting after a couple hours and only will do it one time. I explain it a bit better on the other thread.

I am going to try and get a video before I install the new manifold. Link to new thread below

https://www.f150forum.com/f118/read-...-5-0-a-535451/