need help diagnosing a ratte

[oc192]

This may be hard to do over the internet but here it goes.

About 2 months ago when it started getting cold in AZ (around 40ish :biggrin my car developed a rattle on the driver side up front somewhere. The rattle would start at about 30 mph and remain steady from there on. While cruising at 30+ mph, the noise remains even after dropping it in neutral and coasting. While sitting in the driveway, I can rev the engine up to 2000+ RPMs and not hear any noise at all.

Fast forward to today, I drove it around this morning after it has sat for about a week, the noise seems more pronounced and comes in earlier then before.

The noise sounds like plastic to me and is more pronounced when the windows are up.

My uncle went for a ride with me and thought maybe my throttle cable is loose? Also, while driving today, the speed on my digital dash became dim while the other numbers remained bright (trip and gas). Checked the voltage on the scanmaster , it was 14.1 at the time. I only mention this because he mentioned the throttle cable, not sure if it is remotely related or not.

Any ideas before I take it somewhere and spend money?

 

[gn86randy]

Try putting some vaseline on the Rubber Hood Stopper under the hood in center. need more info as to where it is coming from.

 

[oc192]

Thanks Randy, I'll give that try. The noise seems to come up front on the driver side. I suspected the CAI at first but that is nice and snug.

 

[notacarlo]

Try putting some vaseline on the Rubber Hood Stopper under the hood in center. need more info as to where it is coming from.

that's a sound reply in my opinion. I'm willing to put a five spot on it.

 

[chevellejoe]

Is the noise cause from the speed of the car or the bumps in the road? Does it go away when breaking? Possible windshield adhesive is bad and the temp will effect how bad it sounds.

 

[oc192]

Is the noise cause from the speed of the car or the bumps in the road? Does it go away when breaking? Possible windshield adhesive is bad and the temp will effect how bad it sounds.

At first it was speed related, like clock work it would begin rattling at 30mph. Now it seems a little more random. It remains while breaking until you get below 30, at least that is what it did before. I need to make some more test runs since it is more random now. The intercooler shroud under the car has seen better days, I might look at removing that or the plastic dam around it. I'm going to try the rubber hood stopper first though.

 

[87NAT]

that's a sound reply in my opinion. I'm willing to put a five spot on it.

I will see your five and raise you 10.

Grease on the hood pad when the temp drops..:smile:

 

[HighMileage]

You mention it being speed related. Is it bump related?

Possible speedometer cable? Had an old Chrysler that had a dry cable. Would make noise only at certain speeds and temps.

But that was more of a rattle/squeak.

 

[oc192]

You mention it being speed related. Is it bump related?

Possible speedometer cable? Had an old Chrysler that had a dry cable. Would make noise only at certain speeds and temps.

But that was more of a rattle/squeak.

yeah, that's what I meant to say in my OP. My uncle thought maybe it was a speedo cable. Would there be any relation to the MPH numbers on the digital dash dimming? Also, where can I find the speedometer cable to determine if it is loose or not?

 

[Blazer406]

I would bet the bumper on the center rear of the hood as well.....I like to never have found that....

 

[GNRick]

My speedo cable makes noise when the temp drops. I don't have a digital dash but if we have the same cable then that could be your problem. You would have to pull the dash out to get to the cable. Then put that stuff on it that you use in the door locks.

 

[Dennis Kirban]

Here are my thoughts....

On the speedo cable I don;t think it would be a rattle as it would be very consistent and vary with speeds....

At the very least as suggested put some white grease on the bumper under the hood up in the center on the snubber gizmo by the firewall....as it could be your hood shifting...but that sound is more like your windshield cracking.

I would look hard at the area of your firewall under your hood...I have found on the drivers side the small plastic check valve back by the erg can sometimes tap against the firewall its plastic and will emit a low taping noise.

Can be frustrating until you find it and weather can make it wore or better.....good luck on the hunt....worse case turn the radio up louder....

denniskirban@yahoo.com

also your steering wheel the base collar see if it is loose if it is, need a wheel puller to pop it off and tighten the 3 mini screws...thy can cause a rattle....I drove a lot of these cars over the years....

 

[HighMileage]

yeah, that's what I meant to say in my OP. My uncle thought maybe it was a speedo cable. Would there be any relation to the MPH numbers on the digital dash dimming? Also, where can I find the speedometer cable to determine if it is loose or not?

On some cars,the cable housing can be unscrewed from the side of the tranny. It looks like the female end if a garden hose. Once that is off,the long,moveable piece inside the housing can be pulled out,lubed,then can be fed back in. Each end is squared,so a little wiggling is needed sometimes when it's almost all the way back in.

Not sure if our cars fit that criteria mentioned above,because I have never had my GN's cable out. Maybe someone here can confirm it is the same removal procedure.

It would be that long worm thingy inside the cable housing that would be causing your noise. It connects the speedo drive gear on the tranny to the speedo head.

 

[notacarlo]

There's a short cable from the back of the speedo to the long one that goes to the tailshaft. IIRC the short one is disconnected and lubed.

Still got $5 + a raise of $10 on the hood bumper.

 

[HighMileage]

There's a short cable from the back of the speedo to the long one that goes to the tailshaft. IIRC the short one is disconnected and lubed.

Still got $5 + a raise of $10 on the hood bumper.

Ok. I'll see your raise of $10 and up it more with a used 640 belt that its a noisy speedo cable.

 

[notacarlo]

I reserve the option to purchase insurance on my wager.

 

[oc192]

I reserve the option to purchase insurance on my wager.

too late for insurance, I might be sending my paypal info over to you:biggrin:. I will be lubing up that hood bumper here shortly and taking it for a spin. The sound I hear is like a flapping noise or something, hard to believe it could be the hood bumper but stranger things have happened.

 

[notacarlo]

"flapping"!!

Damn.....Highmileage may be rolling in it on this one. I will be sending a set of used 355 belts to him.....I don't need any VW 640 belts. :biggrin:

If flapping was a description used in the initial post, I may have swayed to the speedo cable.

I vote the bet be terminated due to misinformation.

 

[oc192]

motion to terminate on grounds of misinformation has been granted.

OK, lubed up the hood bumper, still have that noise. Call it flapping, tapping, rattle, whatever it is still comes on at 30mph. The frequency of the noise becomes quicker the faster I go. GNRick mentioned earlier that the dash would have to come out to get to this cable, if that is the case this might be best left with professionals. Removing the dash seems pretty intimidating.

 

[oc192]

also, would a speedo cable noise be subtle to where you can barely detect it coming from the dash area or would it be loud enough to think it was coming from the front of the car?