my 1999 f250 turbo diesel chatters when idleing the noise comes from some where in the engine compartment ive tried to find the source but i have been unsuccessful. the chatter only occures when the engine is idleing and the noise goes completely away when therpms reach about 1200rpms. could some one help me out by telling me where the noise is comming from. if its a problem. how i can fix it or decrease or eliminate the noise (its very loud and im moving to an area with noise ordinance). i much oprecciated all your help.

 

some one please reply, i beg you. lol!

 

Noises are the worse to try and diagnose or explain at the forum level..Especially on a diesel, more so if a7.3.. First, has this noise been there since new if you've owned it that long, or when did it start? Here's a link to Dieselmann's site that has an audible idle for the 7.3.. A 'textbook' 7.3 idle for noise. http://www.intellidog.com/dieselmann/home.htmlNow,,, how does yours 'differ' from this idle on the link.. Louder, knock ect...

 

thank you for your reply. yes my truck makes that noise. but the chattering is much louder and goes over that noise durring idle.( from idlerpms-aproximately 1100 rpmsis the only time the noise is present)when the trucks idle reving system kicks in it goes away because the rpms go over 1100 rpms. or if you rev the engine it will go the same whenthe rpms hit about 1100 rpms. the sound does not seem to be in unisun with the engines normal soundlike dieselmann's. the sound is sharper louder. (not a hard grinding, not a squeeking, i dont thinks it is piston slap. ive heard descusions about that.)

 

ok i have found that the noise seems to be coming form the turbo area, does anyone know what and why the noise is there? Is it a bad thing, how fix it? (I am moving to a naborhood that has noise ordinance and id like to be friendly to the naborhood.) any replies will be helpful thanks.

 

Does it sound more like, or similiar to a rod knock?

Sometimes the 7.3's can suffer from an injector 'cackle' on the #8 injector.. (left/drivers side rear injector) that at low engine RPM's can create what sounds like a knocking rod.. Also, the 4R100 in 99 had some problems with the torque converter clutch 'rattling' which may be more like a chatter as you describe, but is usually easily heard from along side/under the truck..

 

My 1999 F350 has the same problem.Ridiculously loud idling. I was told by the dealer it was the torque converter.Right on Hayapower!

 

if it's a manual tranny it's probably the dual-mass flywheel

 

Tell us more about the Dual mass Flywheel. I have a 1984 6.9 that someone put a later model 5 speed overdrive Trans in(don't know which one but I think its a AZF ?) and it rattles like crazy at idle but stops just up off of idle. The rattle is definitely coming from the bell housing. Anything you would share would be helpful.

 

The dual mass flywheels are/were designed to 'transmit' less engine vibration to the driveline, and give a better driving experience by isolating torsional crankshaft 'spikes'.. Dual Mass flywheels 'seperate' the mass of the flywheel between the engine and transmission... They also reduce some of the jarring and stress on/to the transmission and remainder of the running gear.. They don't take overloaded conditions, or 'added on'power well though.. They are tuned systems and must be matched to the engines torque curve, engine resonant characteristics, vehicle load curves (including axle ratio/tire size calculations). They work by having a set of springs inserted between two rotating masses (thus dual mass). The springs are sized to soak up some of the resonant vibration from the diesel engine under load conditions. A dual mass fly wheel generally also contains an over torque friction release, so if it gets suddenly overloaded, rather than damage the springs, it slips. This works fine as a safety valve, but if it does it much, it burns up and can/willdestroyed the springs..The single mass flywheel can be used in it's place during replacement, (usually because of cost) but WILL tend to transmit more engine pulse (vibration) to the drivetrain and will seem a bit rougher on launch. I believe the replacement clutch plate has a redesigned hub//spring to compensate for the dual mass..