I already have a post up for why my downpipe is glowing at idle after driving it and why i am getting poor gas mileage. Well as of last night I started to hear a noise under the hood that I can only describe as a rattling bike chain sound. I hear it at idle as soon as i start the car now and it gets louder as i give it gas. All my temps are normal. Vaccum is fine. Boost is good. Idling around 850, 900. All the power is still there. The only odd thing that i noticed was the rpm's jumping last night. I was in 5th gear cruising a little over 3,000 rpms and then all of a sudden the needle for the tach jumped from 3,000 to 5000 rpm's and then back to 3,000. I was not giving the car more gas when this happened. The needle did not move smoothly when this happened. It looked like it was shaking when it jumped up and down between rpm's. I downshifted to 4th gear and it was doing the same thing with the rpm's. I checked the PFC and the rpm's were jumping on there just like the tach was by itself. I pulled the car out this morning and popped the hood. As soon as I started the car, the noise was there, rpm's were fine. My brother looked under the hood as I gave it some gas. The noise was amplified as I gave it gas, but I can't tell where it is coming from. The only thing my brother saw was by the airpump. He gave it gas I could see. All the pulleys are spinning. When you give it gas the triangle shaped piece connected to the airpump stopped spinning and when I let off the gas, the traingle piece started to spin again. I'm not sure if it is suppose to do that. Just trying to figure out what the noise is. Could it be a bearing going in the airpump. Should I go to pepboys and buy a stethoscope and see if I can hear where the noise is comning from. If it was the airpump causing the noise, could that be making my car run richer than normal? The one thing I just realized from looking at the pic below is I do not remember seeing the thick black hose that is connected to the airpump today. This pic was taken about a week and a half ago. I will check when I get home tonight to see if that is there.

 

might want to check the water pump

 

if your tack was jumping up and down it could also be the alternator. or like the previous poster said check the waterpump it could be locking up and stopping the alternator.

 

I say check the hoses that go to air pump and ACV (wiring in this case too)

 

I'll check all that stuff in the morning when I can see. I did just pop the hood real fast and the black hose from the air pump to the intake was there. I guess I just must have thought I didn't see it connected when I looked earlier.

 

I had the same problem. WD 40 on the hood hinges and the sound went away!!!

Super77

 

Your jokin, right? Anyway i'm pretty sure squeaky hinges are not going to be making these sounds and get louder as I give it gas, plus my rpm's were going all over the place without my giving it more gas.

 

I didn't have a chance to check anything this morning, maybe when I get home from work. I just had a new water pump installed a few weeks ago because mine had a little leak. I had a new alternator installed that day also. My old one was fine, I just got one powdercoated. The airpump lines were not touched at all and the car was running great the last time I was able to drive it. My problem is that the car was sitting outside for 3 months because I flooded the engine. I'm just wondering from sitting that long without driving it caused parts to dryout. The airpump is original. Is it possible that the noise I hear could be a bearing from the water pump? And can anyone tell me if the triangle shaped part that spins on the airpump is suppose to stop spinning when you give the car gas, because mine stopped spinning when I gave it gas.

 

the "triangle" piece on the airpump pulley is the clutch. it only spins the air pump at or around idle up to a certain RPM (i forget exactly) so thats normal for it to stop when you give it gas. i agree with the alternator causing the RPMs to jump like that. same thing happened on one of my other cars when the belt snapped. that may not be the case with you, but go have it tested at autozone or something. that black hose from your airpump to intake is supposed to be there. thats where it pulls the air from.

i have never had that noise in my FD though so I can't help you there. it sounds like something may be loose and rattling. look under the hood and push down on the throttle cable next to the throttle body to give it gas (not saying you don't know how to do that already, but just in case LoL) and just listen around. it may take a little while but you will find it

 

I had the same problem/noise in my talon. Except it didnt sound like a bike chain. IT sounded like if you're driving and your belly pan dropped to the floor and you started to drag it. Something like that but in a more bass tone and not as loud. lol kinda hard to explain.

Turned out to be the water pump bearing. The pump was fine, it didnt fail to circulate the water but the bearing was bad and that caused the noise.

Changed the pump and no more noise.

Good luck.

 

Thanks, I wasn't sure what the triangle piece was called and if that was normal for it to stop spinning. Well I can elimiante that as not the problem.

I knew the black hose was suppose to be there. I actually thought I didn't see the hose when I checked the car in the afternoon yesterday, because I looked at a pic of my engine bay and when I saw the black hose in the pic, I thought I remembered not actaully seeing the hose there earlier when I was checking under the hood, but I popped the hood when I got home and it was there, but thanks alot for the info. Oh and thanks for the cable info, but that one I did no, haha. I have been listening around in it, but it is kind of hard to tell where it is coming from. I think I might go to an auto store and see if they have a stethoscope. Maybe that might help me pin-point where the noise is coming from.

 

i would get it to the shop; a problem such as this cannot be diagnosed with symptoms unfortunitly. does not sound very good; could be misfiring and detonating. i wouldn't drive it if i was you. the "triangle" piece on the airpump is the electromatic clutch, and yes, it is supposed to disengage above idle. your tach output comes from the power-fc, and it gets it's input from the coils. I don't know what else to tell you, could be the flywheel hitting something, could be internal, but i don't like seeing rpms fluxuate erratically.

 

P.S. This sound has to be something that is spinning. Check all fluid levels for one, and use that stethescope on the back of the pulleys, then move to the transmissionbell housing. let me know what you find

 

I will check the fluids and i will let you know what i find after using the stethescope. Thanks for all the help.

 

Nope, not joking at all. Give Ray a call at Peter farrell's. He is the one who told me how they fixed the chain sound. NOW, what I didn't catch was the fact that these sounds get louder when you give it gas or that rpms were all over the place- my bad. Would a turbo that wasn't seated properly cause that?? I know that I had a turbo that wasn't seated right that gave off a whistling sound.

But the chain jingling sounds did go away on my FD after WD 40 was applied to the hinges.

Best of luck.

Super77

 

Well I went to Pepboys last night cause they said they had one stethoscope in stock and said they would hold it for me to pick up after work. I get there and the person who said they would hold it just left and the person working in parts had no idea where she put it. Luckily I asked a friend today and they had one, so I will check tonight to see where the noise is coming from. Just for ***** and giggles, I will spray the hood hinges with WD 40 and see if this noise goes away, but as far as running rich and the rpm's jumping, that is another problem. At least if the cause of the noise is from the hinges, I will feel safer driving up to Dave at KD to check the car out.

 

I just started the car and used the stethoscope. I put it on the alternator, water pump, air pump. power steering pump and nothing. Then I started to check all the pulley's and as I got lower towards the ecentric pulley the noise was getting louder. I put the stethoscope in the center of the ecentric pulley and that is where this odd noise is coming from. It sounded more like a grinding rattling sound with the stethoscope, but it was definitely coming from the center of the ecentric pulley. I had a set of unorthodox pulleys powdercoated and just had them installed late february at KDR. Anyone have an idea what the problem could be. Coming from the center of the pulley in the pics below.

 

Dumb question but did you make sure you tightened the bolt to that pulley?

 

Well, that's not good news.

Have you checked your oil level? recently had any oil pressure problems?

 

I am going to check tonight to make sure it is tight. I just wanted to check where the sound was coming from last night.

 

I checked all the fluid levels a week ago and everything was good. My oil pressure was good. I will check the level and pressure tonight to double check.

 

Is it possible that the CAS timing ring is loose? That might account for the jumpy tach and the rattling.

If it is, you should be able to feel some play in it, with the engine off, of course.

Dave

 

It could be your oil pump drive chain which is bad news. The fact that it gets louder near the ES seems to reinforce this. It won't immediately destroy your engine or anything but you run the risk of it slipping or breaking and thats the only way your oil pump gets driven so you lose all pressure. Its not extremely difficult to change just pull the pulleys and brackets and yank the front cover, if nothing else just pul the cover to inspect it you wil only be out some time and a gasket or two if theres nothing wrong with it and you an eliminate it as a problem. I just noticed you had the pulleys replaced recently so definitely check the hardware for correctness and proper seating of the pulleys. Let us know what u find out.

 

As soon as I read 'bike chain sound', my mind IMMEDIATELY went to oil pump chain. Frankly I'm kind of surprised that it took someone this long to suggest that.

Since the oil pump is driven by the eccentric shaft, it would definitely make sense that the noise gets worse as the revs increase.

 

I also taught about that being the problem but didnt sugest it for the fact that his RPM's were fluctuating so that taught was discarded but yeah it's obvious that is the only chain under the hood. hopefuly thats not the problem that would be a pain it the *** to fix.