Ticking noise under acceleration?

-
Shaun65dart

Shaun65dart

Well-Known Member
Joined
Oct 14, 2017
Messages
150
Reaction score
66
Location
Lomita, ca
hey guys. 65 dart, 225 slant 6, 904 trans.

So while accelerating, there is a very pronounced ticking noise like tapping a pen on a desk. More I press the gas , louder and faster it gets. If I just cruise with barely any gas, the noise is still there but much more faint. Now, while in gear, if I shift to neutral, and rev, the noise is gone. It’s only while in gear and under a load

Thoughts about where I should look?
 
Cracked flex plate. Loose torque convertor bolts.
 
Shaun65dart said:
hey guys. 65 dart, 225 slant 6, 904 trans.

So while accelerating, there is a very pronounced ticking noise like tapping a pen on a desk. More I press the gas , louder and faster it gets. If I just cruise with barely any gas, the noise is still there but much more faint. Now, while in gear, if I shift to neutral, and rev, the noise is gone. It’s only while in gear and under a load

Thoughts about where I should look?
Click to expand...
Possibly detonation ... timing advanced too much or carbon build-up??
 
Those are two good answers...I would start with the "flex plate." Could be cracked. A cracked flex plate will show up under a load. They usually crack near the bolts to the torque converter. Check out the sound of a cracked flex plate.

 
Doesn’t sound anything like that video. At idle or revving there is zero noise. Only happens in gear
 
Well well took another listen and it does sound like the video just much much quieter. So first thing just take a look at the flex plate?
 
Exhaust leak is my guess
Several ways you can check for exhaust leaks.
Visually check for carbon marks around the exhaust manifold
Spray soapy water on a cold exhaust manifold right at start up and look for bubbles
With car off blow air into the exhaust pipe (hair dryer or shop vac on reverse) and check for hissing sound at exhaust manifold
 
Not all flex plates make the same noise as whats in the video, that was a loose one.
Exhaust as mentioned can make a tick too
 
It may be out there, but have you checked your oil or could there be an oil delivery issue? Not sure if slanties came equipped with hydraulic lifters from the factory, but a lifter that's short on oil would tick like a grandfatherclock on adderall.
 
Here is where you need someone to do a little brakie whilst you poke around under the hood.
Dont go under the car during this process.
 
Check the simple stuff first.

Exhaust leak

Mis-adjusted (loose) lifter since it's a /6 (But if it were that I would think you'd still have a tick no matter what)

U joint, since it doesn't do it when it's not in motion and does under load, I would check those closely.
 
Exhaust leak, had ticking this summer. Was exhaust manifold gasket passenger side on bottom. Replaced it, ticking went away. Good luck
 
My exhaust pipe does like to scrape on my steep driveway also. Could be that too. Hopefully nothing too serious. If it’s a cracked flexplate would i hear it all the time? For example I don’t hear it on the freeway. Really just when going down the street and I pass parked cars and the sound echoes
 
Shaun65dart said:
My exhaust pipe does like to scrape on my steep driveway also. Could be that too. Hopefully nothing too serious. If it’s a cracked flexplate would i hear it all the time? For example I don’t hear it on the freeway. Really just when going down the street and I pass parked cars and the sound echoes
Click to expand...
That was mine also, when I was in town driving by cars or buildings with the echo
 
Yup, a single-cylinder exhaust leak will make a tap-tap-tap noise that's louder under load and quieter (or inaudible) with no load. Usually this kind of leak is at the manifold-to-head gasket, or less often in one of the exhaust manifold runners (crack). Stick one end of a long piece of small-diameter hose in your ear. Play the other end of the hose around each of the exhaust manifold runners right where it meets the head with the engine idling and see if you can hear your tapping noise.

If you decide to go ahead in this direction, It is very much worth your while to get the good gaskets for the manifolds-to-head and intake-to-exhaust junctions unless you like doing the job more than once in a row.

The other main tap-tap-tap suspect on a Slant-6 is excessive tappet clearance. These engines need periodic valve adjustment.
 
I checked the dart out yesterday. So while the engine was running I got underneath and took a look at the flexplate cover. Missing one screw on the passenger side. I pushed it flush against the bell housing and sure enough the same ticking noise came back. I then removed the entire cover and at the top of it the sheet metal was slightly bent in and there were marks where the converter bolts were hitting it

I bent the plate back into place. I then took a look at the bolts and flexplate, everything looked perfect. Also while running it looked fine. I put the plate back on and tightened everything up, noise was gone!

Next I decided to pop the valve cover and double check my clearances that I had just set 2 weeks ago. Everything here looked good as well. I then took the car for a drive and what do you know? The ticking noise is still there! It’s much more noticeable when in lower gear and accelerating hard. For example, when taking off from a stop if I drive it hard, the noise is louder, if I let off the pedal to just cruise, you can’t really here it anymore. Pretty darn sure it’s just an exhaust leak at this point. I do not notice the noise at higher speeds either. Say doing 40 or 50mph, I don’t hear it anymore
 
Shaun65dart said:
I checked the dart out yesterday. So while the engine was running I got underneath and took a look at the flexplate cover. Missing one screw on the passenger side. I pushed it flush against the bell housing and sure enough the same ticking noise came back. I then removed the entire cover and at the top of it the sheet metal was slightly bent in and there were marks where the converter bolts were hitting it

I bent the plate back into place. I then took a look at the bolts and flexplate, everything looked perfect. Also while running it looked fine. I put the plate back on and tightened everything up, noise was gone!

Next I decided to pop the valve cover and double check my clearances that I had just set 2 weeks ago. Everything here looked good as well. I then took the car for a drive and what do you know? The ticking noise is still there! It’s much more noticeable when in lower gear and accelerating hard. For example, when taking off from a stop if I drive it hard, the noise is louder, if I let off the pedal to just cruise, you can’t really here it anymore. Pretty darn sure it’s just an exhaust leak at this point. I do not notice the noise at higher speeds either. Say doing 40 or 50mph, I don’t hear it anymore
Click to expand...

Take the cover back off and try it under a load out on the road again without it.
 
You must log in or register to reply here.
-

Back
Top