Why are non-pushrod modular motors so noisy?

MustangLX-5.0 · Dec 1, 2008

I'm not a newb to motors.Just used to 5.0's and 3.8's.These compared to 4.6's are super quiet when they run.4.6's...5.4's ,3.5's ,3.7's ...they all sound very noisy.When they are running at high rpm's,they sound like they are knocking loudly.

I have never seen the internals of a non-pushrod motor so I don't have a visual to explain this.

Appreciate the replies.

bhuff30 · Dec 1, 2008

I've never noticed OHC engines to be noisy. You are talking about valve train noise, like clicks and clanks? You shouldn't hear much of anything from the valve train, especially over the exhaust.

mogs01gt · Dec 1, 2008

MustangLX-5.0 said:
I'm not a newb to motors.Just used to 5.0's and 3.8's.These compared to 4.6's are super quiet when they run.4.6's...5.4's ,3.5's ,3.7's ...they all sound very noisy.When they are running at high rpm's,they sound like they are knocking loudly.

I have never seen the internals of a non-pushrod motor so I don't have a visual to explain this.

Appreciate the replies.

The injectors are on top of the engine and are in a composite plastic intake, you can hear them pretty easily.

MustangLX-5.0 · Dec 1, 2008

Not the injector clicking.It's the noise that you hear during every crank "lope".Not a click,or tick...louder and more of a metallic "thud".

mustang50v8 · Dec 1, 2008

my 32v sounds like a sewing machine. its that noisy. i dont know why, but it runs great.

MustangLX-5.0 · Dec 1, 2008

Listen to a Crown Vic,GMQ or Lincoln Town Car.The noise is more easily heard in those because of quiet exhaust.

mogs01gt · Dec 1, 2008

MustangLX-5.0 said:
Not the injector clicking.It's the noise that you hear during every crank "lope".Not a click,or tick...louder and more of a metallic "thud".

hmmm the OHC engine allows for a larger cam. I still have no idea which sound you are referring to.

BurningRubber · Dec 1, 2008

Hmmm, a thud is no good. Never heard an engine that made a thud that wasn't about to chuck a rod out of the block, lol.

Mine makes a rotational noise, not a normal valvetrain noise, and not a rod knock. It's internal, but I can't figure out what it is... I have only heard it on a few other mod motor Mustangs though, so it's not a normal thing.

I think these engines are really smooth and quiet.

joshheat25 · Dec 1, 2008

They are just beasts thats all! lol

MustangLX-5.0 · Dec 1, 2008

Hmm,will have to find a sound clip somewhere.I hear these motors everyday at work.Asking one of the other techs this same question,I get "Oh it's noisy because its not a pushrod motor".Wtf kind of answer is that?

You guys may not know what I'm talking about because you may be so used to hearing your motors everyday that you pay no attention to it.

I know it's not knocking.Maybe "thud" is too extreme sounding.More like a heavy "tapping" sound from a thick piece of metal.I dont hear this sound in pushrod motors.

Shrug

bhuff30 · Dec 1, 2008

A thud? I've heard loose main bearings can cause that kind of thud noise, but never heard that for myself.

MustangLX-5.0 · Dec 1, 2008

No...this is a normal engine noise.

NM.

mogs01gt · Dec 1, 2008

MustangLX-5.0 said:
Hmm,will have to find a sound clip somewhere.I hear these motors everyday at work.Asking one of the other techs this same question,I get "Oh it's noisy because its not a pushrod motor".Wtf kind of answer is that?
You guys may not know what I'm talking about because you may be so used to hearing your motors everyday that you pay no attention to it.
I know it's not knocking.Maybe "thud" is too extreme sounding.More like a heavy "tapping" sound from a thick piece of metal.I dont hear this sound in pushrod motors.
Shrug

I've built SBF and SBC's. I have no idea what you are talking about.

LaserSVT · Dec 1, 2008

BurningRubber said:
Hmmm, a thud is no good. Never heard an engine that made a thud that wasn't about to chuck a rod out of the block, lol.

Mine makes a rotational noise, not a normal valvetrain noise, and not a rod knock. It's internal, but I can't figure out what it is... I have only heard it on a few other mod motor Mustangs though, so it's not a normal thing.

I think these engines are really smooth and quiet.

Spun bering is your issue I would bet

As for the OHC nois IDK.
My Mark VIII is whisper quiet even at WOT and my Cobra dosent have any engine noise other then the faint tick of the injectors and the whine of the blower. It squeaks but thats because my Steeda tensioner pully is going out.... crap, forgot I needed to order that

98COBRA281 · Dec 1, 2008

when my motor is warm, all i can hear is the injectors, but when its a stone cold start, it sounds a little "lose"

LaserSVT · Dec 1, 2008

98COBRA281 said:
when my motor is warm, all i can hear is the injectors, but when its a stone cold start, it sounds a little "lose"

Chain tensioners or hydraulic lash adjusters. Prolly tensioners though.

98COBRA281 · Dec 1, 2008

LaserSVT said:
Chain tensioners or hydraulic lash adjusters. Prolly tensioners though.

yeah, i want to get new tensioners for my new motor.....

2000GTdriver · Dec 1, 2008

The cylinder bores on the 4.6 are kinda short so when the piston is at the bottom of the stroke it is not supported very well, can allow some "piston slap" noise when the engine is cold. That is also why a stroker crank does not increase displacement very much-if the stroke gets much longer it pulls the piston skirts out of the cylinder bore at the bottom. Still these engines are usually quiet and smooth when warmed up.

BurningRubber · Dec 1, 2008

LaserSVT said:
Spun bering is your issue I would bet

I have thought about it, but if it's a bearing i'd put my money on it being a main and not a rod, because it has withstood alot of abuse and a bad rod would have let go long ago.

It never gets louder, been the same pitch since I bought it almost 40k ago...

BTW, Laser... I thought about you today man...

Seriously though, this clean Mark VIII rolled by and it had the same wheels your does. I thought, hmmm... Lazer is probaly cruising around in his Mark right now...

Mattstang04 · Dec 1, 2008

I kinda get what ur saying. Before my pipes, the motor had a pretty good growl at the top end in stock form. Not really a sound of something being wrong just a good rumble. I will add that offroad midpipes really let you hear the valvetrain.

Why are non-pushrod modular motors so noisy?

MustangLX-5.0

bhuff30

mogs01gt

MustangLX-5.0

mustang50v8

Member

MustangLX-5.0

mogs01gt

BurningRubber

joshheat25

Member

MustangLX-5.0

bhuff30

MustangLX-5.0

mogs01gt

LaserSVT

Got FB banned again for saying nards

98COBRA281

LaserSVT

Got FB banned again for saying nards

98COBRA281

2000GTdriver

Member

BurningRubber

Mattstang04

Similar threads

Why are non-pushrod modular motors so noisy?

Member

Member

Got FB banned again for saying nards

Got FB banned again for saying nards

Member

Similar threads

Privacy & Transparency

Privacy & Transparency