Major Mystery Rattles

[ives]

I know there have a been numerous rattle stories, but this one is gaining in mystery day by day.

I just bought my 04 Jetta GLS TDI Jan. 1 with 57k on it.

almost immediately I stated hearing this very loud rattle every time I went over a bump or heave in the road. It sounds like it's coming from passenger door... (the car is under warranty)... my local dealer spent a few hours trouble shooting, replaced the actuator bushings or brackets or both..... no good....... then they replaced the entire actuator.......no different, even slightly worse.

Sometimes it sounds like its from the dash near the glove box, sometime it sounds like its from the center column, sometimes I don't hear it for a day.

VW has no idea what to do... I just read about the spray... but I wouldn't even know what to spray since I can't pin the location down.

AND NOW... there are major rattles starting in the middle of my dash that act up between 1200 and 2000rpm.

Is the spray the best bet, or should I be looking into other avenues? Are their certain things that tend to rattle in that area?

HELP.

 

[ives]

no one has any ideas or helpful hints?

 

[BobnOH]

pennies in the air duct?

 

[RacerTodd]

Well, here is a method that might help you. I've used it to track the source of noises in the engine compartment. This worked superbly to locate an exhaust leak in my old Golf. I assume it would work inside a car as well. And, best of all - it's dirt cheap!

The problem is that our wonderful ears are too omnidirectional, making it hard to pinpoint the precise location of a sound. Also, sound bounces all over the place, masking its true location.

Start by plugging one ear. A foam ear plug works best. Taping a cotton ball over the ear might work. A finger is OK as a temporary measure.

Take a length of several feet of vacuum hose and stick the end in your other ear. Don't be a moron and jam it inside the ear canal! Just place it gently against the end of the ear canal. You just want to ensure you don't get any sound from anywhere but the hose. Any type of small diameter (1/8-1/4" ID) flexible hose can be used: vacuum hose, clear plastic tubing, etc. The length will depend on how far your ear will be from where you are investigating.

Your ears are now insulated from outside noise - except for those sounds coming from directly in front of the hose. The hose make your ear act like a highly directional microphone. Pointed directly at a source of sound - you'll hear the sound clearly. Point it 1/2 inch away - you'll hear nothing. You want the end of the hose to be very close to the item - within an inch or two at most.

Since your rattles only appear when driving, I'd strongly recommend having a passenger do the listening while you concentrate on driving! Driving with your ears plugged is a recipe for disaster!
Find some bumps or sections of road that produce the rattle then travel over them repeatedly while your passenger moves the end of the hose over various locations where you suspect the noise is coming from. The noise will be loudest when the hose is pointed directly at the offending location.

If you suspect the rattle is inside a door, removing the door panel might help. The thick panel might disperse the sound and make it harder to locate.

If you need more reach, tape the end of the hose to a long stick or screwdriver. This works great if you're trying to listen to something in a tight space where you can't get your hand - like listening to the AC compressor on a TDI. If doing this in the engine compartment, keep your hands and the hose out of the way of moving belts and hot exhaust parts!

It's kinda of cool to run the hose over various parts of your engine while its running. You can clearly hear alternator, AC and power steering pump bearings, valvetrain noises, etc.

You could also buy a doctors stethoscope, cut the end off and extend the hose by a couple of feet.

 

[keggo]

Does it only happen while in motion? I found that the heatshield for the inner passenger cv boot was very loose and was touching the axle flange, causing a horrilbe noise while in reverse. The sound became worse during forward movement as time went on...

 

[Canadian_Grizzly]

Todd great advice...

 

[Luv My 02 TDI]

How about this for $2.00

And you don't have to worry about how far to put that tube in your ear.

 

[RacerTodd]

How about this for $2.00

And you don't have to worry about how far to put that tube in your ear.

A mechanic's stethoscope (as pictured) has a solid probe which I find works fine for listening for noises inside an engine or trans, etc. For noises outside an enclosure I find the open end of a piece of tubing to work better. This includes exhaust leaks, leaks at the EGR gasket, determining which engine-driven accessory is making noise, etc.

I have a mechanic's stethoscope that I've modified. I can remove the solid probe and replace it with a "Y" adapter and a length of hose.