Strange noise from motor

[JasonCzerak]

I've got this metallic sounding noise coming from the motor, I think.



It's very inconsistent, and typically only hear it when the ambient is below 60. It was around last fall/winter, but not this bad. When it warms up, the truck that is, the noise is much quieter.



It one of them sounds that seems like it's coming from all over. it's not the trans or clutch. I've put it in gear, clutch disengaged, or engaged (and transfer case in N). But you can hear it loud and clean from under the motor.



When the motor is cold, you can near it under the valve cover. I just adjusted most of the valve's lash and there was nothing "extra" under there. Most the valves were off a little. I decided to do this since I got the smarty a week ago and running the motor at higher RPM's a lot now.



I don't think it can be any internal parts since it's rather inconsistent and if I had a barring wearing out, it's be very consistent, and maybe a different sound. And well, I would of blown it up by now! Smart or Edge runs strong and Smooth at all RPM's.



This leads me to injectors (Stock... )



Or can this just be the motor wearing in more, and the typical winter sounds that drives ya nutz?



I have a video camera on hand for the race track day that's tomorrow and I"ll get some audio (and video) of the sound.

 

[Motorhead]

You might want to run an oil analysis.

 

[MCummings]

Probly an idler bearing or tensioner?



Merrick

 

[JasonCzerak]

I run the analysis's all the time. they come clean, well. soots always a little high, but other wise with in spec.

 

[MCummings]

I just re-read your post, and I'll reiterate my thought on that is it most likely a Tensioner going bad.



Pull your belt off the crankshaft harmonic balancer and crank up the truck, then see if the noise is still there.



Do not run the truck for more than two minutes as teh wter pump and fan do not turn without the belt.



Merrick

 

[JasonCzerak]

Ok, I understand what you are getting at. and time permitting I'll try to do that tomorrow.



The noise tho doesn't seem like it's coming from the front of the motor at all.



But I'll try. thanks for the suggestion.

 

[MCummings]

Not rying to be pushy, just I've chased down a bad tensioner for days thinking that wasn't the prob. Of course I can't even hear your truck so it's just as a crazy guess as anybody else's



Merrick

 

[Wayne M.]

This is gonna sound crazy, but I swear by my stethoscope. I can hear anything going on in any mechanical device. I recently listened to my valvetrain (I have no problems) and it's all music in there. If there was a problem I would surely hear it. It's cheap and worth the investment.

Here it is;

Detail Page for 52500 MechanicÂ’s Stethoscope - Lisle Corporation



I was able to pinpoint a noise I thought I heard in the front of the 5. 2 in my Durango, and it was the water pump. At first I thought it was the tensioner, but the tool worked. A side benefit is that you'll really impress your friends/ customers. I get reactions of amazement all the time.

 

[Lurch]

Just watch those spinning fan blades when your poking around with the stethoscope. NOT a sound you want amplified .

A screwdriver held tip to the part and handle to your ear also works surprisingly well to transfer sound, just looks a little strange:-laf

 

[JasonCzerak]

I swore I had a mechanics stethoscope. Can't find it. Can't find my long breaker bar either (might of left it at a friends... ).



I'll pick up both tonight. Getting that Tensioner pulled back is a PIA

 

[Wayne M.]

Just watch those spinning fan blades when your poking around with the stethoscope. NOT a sound you want amplified .

A screwdriver held tip to the part and handle to your ear also works surprisingly well to transfer sound, just looks a little strange:-laf

:-laf Just a slip with that 'scope will wake you up! Always safety first with those things. I keep the 'scope home, and have a long skinny screw stick at the job- that works well too. The good thing about the scope is that you can take the end off and use the tube to listen for vacuum leaks and such. I found a manifold leak under the manifold of a 4. 6 Mustang recently. The shop who had the manifold off sweared there was no leak, but stick the end of that tube under the plenum next to the head and you heard a giant sucking sound.

 

[JasonCzerak]

IT IS NOT anything attached to the serpintine belt

Just pulled the belt. let things cool off for about 3 hours and fired her up and 30 seconds into the start the sound is back.



All pullys spin freely and quietly as well.



I'm thinking injector's.



I need get get a stethoscope now.

 

[TCDiesel]

Just pulled the belt. let things cool off for about 3 hours and fired her up and 30 seconds into the start the sound is back.



All pullys spin freely and quietly as well.



I'm thinking injector's.



I need get get a stethoscope now.

We'll Bring it by and I will do a kill test on each injector. . takes about 10 minutes...

 

[JasonCzerak]

We'll Bring it by and I will do a kill test on each injector. . takes about 10 minutes...

Can you bring the OBD-II deal to the dyno day? if not, let me know I can swing by anytime after 5pm or on a Saturday/Sunday.

 

[PBrauer]

Just pulled the belt. let things cool off for about 3 hours and fired her up and 30 seconds into the start the sound is back.



All pullys spin freely and quietly as well.



I'm thinking injector's.



I need get get a stethoscope now.

Don't rule out the damper (crank pulley) itself... are you shaking a little when the rattle/noise is at its worst? Once the belt is off you're only four bolts away from removing and inspecting it. FSM has specs for the alignment marks... inspecting the rubber is fairly straight forward. Bad damper will send sounds all over the place...



I was going to suggest the fan BEARING until you pulled the belt... Mine had zero play but was dry and badly worn when I finally pulled it.



Also, the tensioner is much, much easier to access from the bottom, BTW. Easier to get to and you can tie it off with a bungee to simplify belt on/belt off. Like a lot of things, I learned this the hard way.

 

[JasonCzerak]

Don't rule out the damper (crank pulley) itself... are you shaking a little when the rattle/noise is at its worst? Once the belt is off you're only four bolts away from removing and inspecting it. FSM has specs for the alignment marks... inspecting the rubber is fairly straight forward. Bad damper will send sounds all over the place...



I was going to suggest the fan BEARING until you pulled the belt... Mine had zero play but was dry and badly worn when I finally pulled it.



Also, the tensioner is much, much easier to access from the bottom, BTW. Easier to get to and you can tie it off with a bungee to simplify belt on/belt off. Like a lot of things, I learned this the hard way.

The damper is a fluidamper. it's less then a year old (early summer maybe). And I need to remove the fan and shroud as well to get that off



The truck does seem to have a slight miss as well if you hold RPM's at 2000-2500.



I'm betting my pennies it's an injector or two.

 

[TCDiesel]

Can you bring the OBD-II deal to the dyno day? if not, let me know I can swing by anytime after 5pm or on a Saturday/Sunday.

I don't know if I will be able to Make it... Health issue's with Family and friends.

 

[JasonCzerak]

Pulled the smarty off and You can hear it, but the sound is extremely faint.



What ever the smarty does (at idle) vs stock software enhances this noise... I hear it faintly this morning (39 degree start).



any ideas based off of this?

 

[Johnstra]

I'm chasing a noise on my truck too. I'm more convinced than ever that mine is injectors. I've been running B20 for a while now, but I had to run a couple of tanks of plain old petro diesel and I noticed a lot more of the ticking, rattling sound with the petro over the bio. I filled up with B20 again today and the sound is back down to where it was - still there but much quieter.

-john

 

[MMeier]

Just did injectors in my rig . . got rid of one noise but now I have this "new" noise going on, gets louder as it gets warmer? Local dr. says its the pilot injection event being eliminated during certain phases of operation, anyone else?