[bigpav7]

so I noticed this annoyng racket coming from the engine while I'm driving near a wall, other cars or a divider. It gets louder when MDS is on and becomes faint again when all cylinders fire up. i tried parking and revving the motor up but heard absolutely nothing at all. Is this the infamous Hemi tick?
Thanks.

2010 Commander Sport Hemi

 

[Mongo]

Are you using the recommended oil viscosity, that the O.M. warns other viscosities will cause problems with the MDS?

A lot of miles with conventional oil might cause some varnish build up that can cause valve train trick. There are some additives that can help remove it, don't know if it will change viscosity and cause problems with the MDS. Synthetic Oil won't produce the varnish build up and will actually clean away varnish build up, and no additives that mess with viscosity.

 

[Matt_]

I know the noise you're talking about... I have it too and it is the "hemi tick".

At first i thought it was a faint exhaust leak and went crazy looking for the source :rofl:

My 2007 doesnt have an MDS indicator so i cant tell if its worse or not when MDS is activated.

 

[Simplewon]

Mine is noisy too. Since new. I recently switched to mobile 1 full synthetic but no change. I'd like to disable the 4cyl mode and will after I get the programmer. I can't imagine it's good for the engine especially since fuel is a lube on the upper rings. I have checked mpg resetting it while in 4cyl mode, can't see that it helps at all.

I hope the programmer will let me disable it.

Thought about just getting a cat back exhaust but those are high, drown out the noise lol

 

[Matt_]

Yeah, the programmer will let you disable it.

 

[bigpav7]

Yeah, I actually started looking for broken manifold studs before googling it. This is extremely annoying, i too would like to find a way to disable MDS, but yeh, these programmers ARE expensive.

 

[lekmedm]

I know the noise you're talking about... I have it too and it is the "hemi tick".

At first i thought it was a faint exhaust leak and went crazy looking for the source :rofl:

My 2007 doesnt have an MDS indicator so i cant tell if its worse or not when MDS is activated.

Really??? I was sure I have an exhaust leak. That sound is normal for the hemi?


rangehat:

 

[Smitty1970]

the v6 is noisy too. Ive read a bunch that says its the fuel injectors that make the noise. IDK I think its an exhaust leak also, just dont know. It is very annoying when the windows are down though.

 

[Matt_]

Yeah. The only thing I haven't done was turn off the MDS with the programmer to see if it goes away/changes. Its definitely not an exhaust leak (on mine anyways)

 

[D-niceCommander]

Wow! I feel good now! I thought I was the only one. We should start a support group. I did have spark knock at idle until I replaced the plugs last week. Now she is quiet.

 

[H311B0Y]

how about an audio clip of those sounds if possible? especially that spark knock never heard that one (im quebecois so different terms here lol)

 

[D-niceCommander]

Mine spark knock is gone. And I'm not putting my old plugs back in to show you.Lol

 

[Holaday07 4.7]

I have a weird Tick when accelerating, but the shop said it was nothing, I am switching plugs next weekend, and puting in Synthetic to see if it goes away. I just don't want to destroy and engine.

 

[D-niceCommander]

Mine was only at idle. It was a ticking. As soon as I raised the idle it went away. I do my own oil changes and use Mobile one synthetic so I know it wasn't the oil. I just lived with tick i thought it was just what the Hemi did. I think it mentions something about it in the Manuel. Then I changed my plugs and the tick gone.

 

[drfeelgood]

I have a 2010 Hemi and mine has made this sound since new. I also worried it might be an exhaust leak. I hear it with windows down when accelerating, not really at idle.
Different oil, filter and multiple Predator tunes haven't made a difference.
So, is it the consensus that this phenomenon is harmless and common?

 

[H311B0Y]

Mine spark knock is gone. And I'm not putting my old plugs back in to show you.Lol

lol! i would have said the same!:rofl: i will try to make a clip of mine well see!

 

[D-niceCommander]

I tried all types of gas and none helped me. I still had a tick..tick..tick at idle. the manual says it can happen at hi speed with bad gas or a low grade. What octane are you using?



FUEL REQUIREMENTS
3.7/4.7L Engines (If Equipped)​

All engines (except 5.7L engines) are designed
to meet all emissions regulations
and provide excellent fuel economy and
performance when using high quality unleaded
“regular” gasoline having an octane
rating of 87. The use of premium
gasoline is not recommended. Under normal conditions,
the use of premium gasoline will not provide a benefit
over high quality regular gasolines, and in some circumstances
may result in poorer performance.​

5.7L Engines (If Equipped)​

The 5.7L engine is designed to meet all
emissions regulations and provide satisfactory
fuel economy and performance when
using high quality unleaded gasoline having an octane
range of 87 to 89. The manufacturer recommends the use
of 89 octane for optimum performance. The use of
premium gasoline is not recommended. Under normal
conditions, the use of premium gasoline will not provide
a benefit over high quality regular and mid-grade gasolines,
and in some circumstances may result in poorer
performance.
Light spark knock at low engine speeds is not harmful to
your engine. However, continued heavy spark knock at
high speeds can cause damage and immediate service is
required.
Poor quality gasoline can cause problems such as hard
starting, stalling and hesitations. If you experience these
symptoms, try another brand of gasoline before considering
service for the vehicle.​

STARTING AND OPERATING 305​

5

II

 

[Matt_]

The ticking noise is not spark knock.

Also, if you have a spark knock issue it will be more pronounced under load and will go away at idle.

 

[bigpav7]

What I dont get is why when the truck is just started and is sitting idling, there is no tick. I can rev it up and still hear nothing. If this is injectors or valves, shouldn't it be making the noise regardless, whether the car is in park of driving?
I am getting so tired of this sound. A hemi just should not sound like this. Time for an exhaust upgrade!!!

 

[Matt_]

My guess would be the sound is created when MDS kicks in which drops the oil pressure to some of the lifters so the valves don't open..... so the ticking we're hearing is the free riding lifters being compressed.

I just turned my MDS off to see if that changes anything.

Also, be careful with exhaust. For any of these vehicles that go from 8 to 6 cylinders (or even 4), aftermarket exhausts are known to sound horrible when the cylinders are deactivated.