I just developed a new squeak / squeal this past week. It sounds to me like a water pump going, although after a full search (yea for me) it may also sound like an idler pulley going or possibly the IAC valve stuck. (My full earlier post is here.)

So, I took some sound clips. Those of you who have had idlers, water pumps, IAC valves, belts, and any other noise-making maladys affect your Lightning, please take a listen and let me know if you can NAME THIS NOISE!!!!

From the wheel well - Wheel well

From under the car behind the wheel well - Underneath

OK, here's the weirdest one - you all know the sound of the vacuum escaping once the truck is shut off for a few seconds. Well, this "noise" follows during that whole time - and the whole vacuum escape time takes like twice as long now! What is this???

At shut off - Shutoff

 

Mine sounds just like that at shut off. I think it always has actually.

 

Sounds exactly like someting in the FEAD to me (front end accessory drive). Pull the belts and spin everything by hand. Other than the PS pump you should'nt feel any axial movement. No roughness anywhere on anything.

Also, the water pump seal if squalling would'nt really "feel" bad to the hand but could sound just like that noise. Spin it as fast as you can by hand... or even better maybe take a cordless drill and spin it to try and see if it makes a similar noise.

on the extended hissing... do you have any gunk build up around the throttle plates? Or maybe a vacumme line has a crack in it?

Rich

 

I'm going to have to try pulling the belts off to see if I can isolate a bad accessory or idler for excessive lateral play.

Rich, my vacuum lines all look like crap, my L seems to be one of the ones that pulls excessive oil through the PCV system and its done a good job of absolutely coating everything with oil, which is why I thought the IAC valve might be suspect (from sucking in oil), although I don't have any idle problems to go with it. But I don't think the extended hiss is a vacuum leak because what would be holding vacuum after shutdown anyway? I have a lunar boost/vac gauge installed in my pillar, and I think it's reading normal vac when running (although now I'll make sure of this tonight). It seems so wierd that after the belts shut down with the engine, the noise keeps seeping for a few extra seconds.

I'll keep looking into it. Thanks for the replies.

 

I think that its the last gasp,from the last srt-10 your lightning ate

 

LOL, I did just put some Nitto DRs on the rear. If we could get some rain to wash the salt off the streets, there would be some more kills for this beast.

 

Oil..hiss I hope it is not a compression leak of some kind...
Is anything low on oil ?

Sorry I'm not that good on autos

 

When you hear the noise, is your coolent in the intercooler resvior swishing? It's a chance it is your intercooler pump going bad.

 

That's another thing I'll check, but the intercooler pump is electric and this noise is definitely tied to engine speed.

 

UPDATE ON RESOLUTION:

I was taking it for a car wash on Saturday, and planned on working on it afterwards, pulling belts, checking idlers and whatnot . . . AND IT THREW A CODE.

I stopped at Autozone for a code reading, and it pulled P0171 and P0174. The codes both refer to lean condition - both banks.

Someone had suggested vacuum leaks on another forum, so the first thing I did when I got home was start checking the entire vacuum systems. Still not finding anything, I decided to pull out the Lightning Enterprise PCV Kit's check valve from the driver's side valve cover. JACKPOT! Strange noise totally gone. The check valve seems to be working still, and I know it was installed in the right direction, so I don't know what was wrong but clearly it was leaking vacuum somewhere. It seems normal now.

Thanks for the suggestions from everyone though.