single "clunk" when starting the engine
Senior Member
Joined: Sep 2018
Posts: 106
Likes: 52
From: Fort Lauderdale, FL
My '19 3.5eb 10spd with 5200 miles has a loud clunk on start up sometimes too.
Doesn't always do it, and doesn't matter if it's hot or cold.
I have an Auto start/stop eliminator switch now too, but never heard a clunk before the rare time the truck restarted itself.
I can't say for sure what it is, but definately the engine or transmission, and more likely the engine.
It's almost as if it happens in a specific location, like how far from TDC the engine is or isn't, if it stops in that position, it clunks on start up...whatever position that may be.
Sometimes I get a cold start rattle momentarily, then that's gone.
I also get the cold start 3-4, or 4-5 lazy shift the first time it shifts through those gears.
All of these issues happen once, for only a moment, then they're gone.
I have no other noises or any driveability issues.
My heated steering wheel likes to come on randomly, if I remote start with heat on 73/74 or above.
My driver seat memory hasn't worked properly 4 times.
Random quirks I wish weren't there, but haven't really caused any problems.
Doesn't always do it, and doesn't matter if it's hot or cold.
I have an Auto start/stop eliminator switch now too, but never heard a clunk before the rare time the truck restarted itself.
I can't say for sure what it is, but definately the engine or transmission, and more likely the engine.
It's almost as if it happens in a specific location, like how far from TDC the engine is or isn't, if it stops in that position, it clunks on start up...whatever position that may be.
Sometimes I get a cold start rattle momentarily, then that's gone.
I also get the cold start 3-4, or 4-5 lazy shift the first time it shifts through those gears.
All of these issues happen once, for only a moment, then they're gone.
I have no other noises or any driveability issues.
My heated steering wheel likes to come on randomly, if I remote start with heat on 73/74 or above.
My driver seat memory hasn't worked properly 4 times.
Random quirks I wish weren't there, but haven't really caused any problems.
My truck has 18,000 miles on it and I have contacted Ford Corporate to make them aware a Lemon process might be fourth coming. They have been extremely helpful so far and we are going to start the process of possibly a buy back if they can’t fix it.
This might be an issue that is common but I’m not interested in living with it.
I will keep everyone posted to my findings throughout this process.
2018 2.7L SCREW, 3.73 Locking diff.
Save the Manuals!
Joined: Oct 2015
Posts: 1,951
Likes: 1,344
From: Delaware
Junior Member
Joined: Jun 2018
Posts: 19
Likes: 0
In 50 years of mechanicing... a couple of times I have run into a loose flywheel causing a ' single ' clunk .
probably not your situation.. but jeez this problem has been there a long time and might be good to check it...
probably not your situation.. but jeez this problem has been there a long time and might be good to check it...
5 Year Member
Joined: Aug 2017
Posts: 83
Likes: 18
Still no changes on my end, 2017 4x4 3.5 eco with 10 speed tranny, 43k miles. As far as I know, only 10 speed tranny does the clunk on start. Mine has become more consistent. If the truck is run, then turned off, in 20-45 mins, the clunk WILL happen. What seems to have gone away is the clunk after sitting all night.
