odd noise under hood???

[jrlugo45]

HI guys,

about a month ago i noticed a odd sound coming from under the hood of my 00 gm. it only happens every now and agian but it sounds like a loud air compressor and it sounds for anout 30 seconds and then fades out, my car is not equiped with air ride so what could this sound be? a/c pump? thanks everyone.


Rob L.

[Merc3517]

The A/C compressor will cycle on and off if you have the Max A/C, Norm A/C, Defroster, or Mix on regardless of whether you have it on hot or cold. The Compressor cycles on and off when the defrost is on because air conditioning will remove moisture from the air which makes it easier to defrost your windshield. If this is what it is do not be alarmed it is normal. You can check by popping the hood and watching the compressor. You will see the clutch engage and disengage if you have the HVAC settings in the described positions.

[ford man]

On my '93 Crown Vic the traction control would make a weird noise but not for 30 seconds. And it would only make that noise when I was romping on it.

[jrlugo45]

i located the sound its coming from the airbox?!?!?!? i removed the clamps and pulled it up to listen and it sounds like its coming from right where the maf is??? any ideas?

[Merc3517]

Hmmm, does the idle change or anything when it happens? Is there a CEL?

[MattsLincoln]

i located the sound its coming from the airbox?!?!?!? i removed the clamps and pulled it up to listen and it sounds like its coming from right where the maf is??? any ideas?

MAF may be taking a dump.

[jrlugo45]

well i dont know what else could go wrong, i took the car to the shop today for several issues to be looked into, now on top of this funny sound, i have to replace coils,struts/shocks, sway bar, ball joints and tie rod ends, the shop even went as far to say that my car is unsafe to drive in its current condition and my bank is not happy, so i am being forced to fix these issues at 750$!!!!!!!! I'm starting to rethink keeping this car....... as for the sound i was told it "could" be the pcv valve? so i am going to replace that, but i really think its the maf because when i unplug the maf the sound stops completly, this seems pretty obvious. thanks guys.

[Merc3517]

I would lay blame on the MAF in my opinion as well. Funny thing about that though. One time like an idiot I left the MAF and and IAT unplugged for God only knows how long and I didn't even notice it. If I had my CEL in it would have probably lit up but it was just one day I was under the hood and was like WTF! Hooked it back up and have had no problems. I don't recommend that but since we were on topic I thought I would share that tid bit lol.

[ford man]

wooo... I don't know about that 750 outlay... How many miles on the car? Do you feel lots of play in the wheel when you drive? Can you have another shop look at it?

[jrlugo45]

The car has 160000 no play in the wheel at all, just a loud clank when turning sharp. for the back of the car today i bought some monroe air adjustable shocks that me and my buddy are going to install sunday.

[Merc3517]

The clank when turning sharp is normal. There are little stops that prevent the steering knuckle from turning any farther and when you are moving the suspension will shift and cause that noise.

[91waggin]

#1: That shop is fucking you. Go somewhere else and get a second opinion.

#2: You don't EVER need to replace the swaybar itself unless it's broken in half. You may need to replace the endlinks on the swaybar and the saddle bushings, but you shouldn't ever have to replace the bar itself.

#3: Replacing the endlinks and the saddle bushings is about the same difficulty level as replacing the rear shocks.

#4: Even if you do NOTHING with the swaybar, it won't make the car unsafe to drive. Might roll a bunch through corners, but it won't be unsafe.

#5: Your car doesn't have any struts. If the shop tells you it does, run like hell. Your coil springs are separate from your shocks. Also, if your friend can install rear shocks, he can install your front shocks.

#6: Tie rod ends are super easy. Get a paint pen and mark on the old tie rod end right where it comes out of the adjusting sleeve, in order to preserve your alignment. Smack the top of the stud on the tie rod end with a hammer after removing the nut until it falls out. Loosen the nut on the adjusting sleeve and unscrew the tie rod end. The threads are reversed. Screw the new one in to the same point that you marked on the old one, and reattach it with a new nut and cotter pin. Hopefully your friend will know how/can figure out how to do this as well.

The best advice I have? Just get under there and have a look and see if you can figure out what's going on. You'll get a good handle on exactly what's going on down there and see exactly how hard that shop is screwing you.

Also, they're probably marking those parts up hardcore. If you haven't yet, mosey on over to rockauto.com Here are my recommendations for the parts in question:

Lower Ball joints (one on each side) MOOG Part # K8685 ($46.99x2 = 93.98)
Upper ball joints (one on each side) MOOG Part # K8678 ($50.99x2 = 101.98)
Coil springs (sold in pairs) MOOG Part # 80090 ($87.89)
Front shocks (one on each side) KYB Part # 344081 KYB gr2's in police valving ($25.79x2 = 51.58)
Swaybar endlinks (one on each side) MOOG Part # K8953 ($44.79x2 = 89.58)

Grand total before shipping from rockauto.com: $425.10

Now, keep in mind that I generally recommend more expensive stuff (Moog) because it's good, but you can save a lot of money on many of these parts, Raybestos also makes good stuff.

Final point: The only thing that is truly safety critical in your front suspension is the ball joints. Everything else can wait if it comes down to that.

Cheers.

[Gsmagnum]

The clank when turning sharp is normal. There are little stops that prevent the steering knuckle from turning any farther and when you are moving the suspension will shift and cause that noise.

Mine doesn't clank, but will squeak when it is turned at just about full lock and I am moving the car.
I have had both the Ford dealer (brake job) and the tire shop (snow tires) swear that all is well with the ball joints and other components.
Either both shops are really good or they are inept and lazy. I am leaning toward really good.
I can do the suspension on mine, but my knees will really protest if I do get down there and work on it. Nothing under the car looked bad when I changed oil.
Mine has 148,000 mi on it.

jrlugo45,

It sounds like the shop shooting for $750 is a bunch of money grabbing scumbags. I would say either change stuff out with your buddy or take it somewhere else for another opinion.

[Merc3517]

Just to clarify. I didn't mean that just because you hear the clank at the lock it's always ok. You may have something wrong but if everything is tight then it is normal but as suggested above not always there. After I put all my weight in my trunk for winter I no longer get the clank. But in the summer when I am light in the ass I will get it at lock.

[jrlugo45]

Thanks guys,
The new rear air shocks have been installed, boy was it a pain though!! it took me and my friend the whole day in the driveway, it came down to the old shocks having to be cut out with a grinder, no ammount of wd40 in the world was loosening up the top bolts, so out came the grinder and off they came, haha. the new air adjustable shocks are awesome!! i installed the air valve in the trunk and it works great. the shop i went to said tierod ends and a sway bar they also said my trac bar in the rear is shot. i went to another shop and they said everything looked fine although the ball joint on the right is worn but not bad and my rear coils are also worn and should be replaced soon. im sure this is all work i can do in my driveway. thanks guys.