[JEFFDHURLEY1]

replaced clutch in my 85 back in Nov.( with new transmission mount )_ car has run great but recently heard a intermittent rumble/ rattle first heard when turning hard left and accelerating
in trouble shooting i checked timing belt tension it was all ok
used a long screwdriver as a stethoscope but could not pinpoint
during that I found that would go away when i lifted up the engine a bit
lo and behold my ac compressor pulley was touching the frame due to seriously worn engine mounts had to drive car and ac does not work anyway so i cut belt .

I then noticed a higher pitch squeal/metallic jingly sound at approx 2700 to 3200 rpm no sound below that rpm and maybe not as much above but hard to hear over regular engine sounds.
is coming from front area of engine

replaced both mounts yesterday and have the battle scars to prove it ( also working on a black car outside no shade in Texas when heat index is 115 is the pits but hey I am an alfisti ). made sure all was tight no loose things to make noise all in adjustment
still have same noise
can find nothing loose and i even stabilized the ac compressor pulley even though not turning in case it was a rattle/sound from there as it would turn on its own when the sound would start .
after much study it seems like sound may be coming from water pump bearing
I replaced the Water Pump New from centerline last August /Sept but noticed when i first heard the grumble rattle during initial troubleshooting that ,that the belt was WAY too tight . adjusted
after yesterdays . wrenching and still chasing the elusive squeal /rattle I noticed that the fan pulley assembly has between a 32nd and a 16th play . Car is a daily driver could a pump bearing go south that quickly due to over-tightened belt ? If not is there another direction the all knowing and powerful alfabb folks could point me towards ?

 

[86spider]

I had an intermittent metallic jingly sound from under the hood once. Found one of the air filter clamps undone and it would swing into the alternator fan.

 

[JEFFDHURLEY1]

yep checked that
all tight and not touching but thanks

 

[ghnl]

You can remove the drive belt and run the engine for a short while. That will take the water pump & alternator out of the equation.

Is the heat shield (under the car) snug? They often rattle - perhaps the sound is being transmitted forwards? (is your Spider a ventriloquist...?)

 

[JEFFDHURLEY1]

all heat shields checked and tight while under car for mount swap
though about removing belt and trying that but ran out of daylight that and needed a transfusion for knuckles

 

[jcslocum]

The heat shield on the exhaust near the steering box on our 86 would make a funny rattle when at about 3500 RPM. Was hard to track down but a good smack with a hammer bent it enough to silence it.

 

[Alfa Romeo Red]

Maybe you lower chain is loose?

 

[JEFFDHURLEY1]

pulled cam cover same day that i noticed mount were shot . although within spec and no signs of hitting cover adjusted top and bottom chain tension was fine .
has anyone else had a water pump fail within a year as that seems to be the source of sound although why just at 3k rpm not sure

 

[Big Bear]

I was driven a bit closer to the nut house by what sounds like a sililar rattle coming on at about the same RPM on a 94 Spider. After much head scratching and knuckle busting I discovered it was the electromagnetic coupling in my de-commissioned AC. I tapped a small wooden wedge between it at the pulley....and "peace"

 

[JEFFDHURLEY1]

thanks big bear i have not put a wedge between the two yet but a small teflon one in a gap in front quietened considerably
i wll be putting a belt back on and charging unit in a week or two and hopefully will be fully solved
even with top off and 70 , at 105 f degrees it is hot driving thanks again

 

[Big Bear]

Jeff

So pleased I was able to help. I have used this forum a couple of times to seek help (and it's been great), but this is the 1st time I have been able to contribute. Hope you get things cooled down. I live in Easter Canada....so, not much need for AC.

Paul
1994 Spider Veloce

 

[Alfa Romeo Red]

I had the top chain tighten and the sound went away.

 

[clescn]

engine noise at 3000 rpm

I tightened the upper chain tensioner and noise didn't go away...any further thoughts on what may be the cause?
Thanks, Nick

 

[ghnl]

Will it make the noise if you rev the engine to 3000 in neutral? If so have your trusted assistant do that while you search for the source of the noise. (be careful of moving parts...) A 2'-3' length of heater hose makes a good stethescope. Hold one end near any suspect areas while listening at the other end. (be careful of moving parts...) You can also touch the hose to things (like the heat shield, catalytic converter, etc) and see if the noise goes away.

 

[Forzaguy]

" also working on a black car outside no shade in Texas when heat index is 115 is the pits "

I feel your pain after living in Houston for over 25 years . . . BUT try it here in Phoenix where the REAL temp is 116F. Rips the hide right off ya! But its a dry heat they say. Right, so is an oven!

 

[clescn]

Yes it does. It also does the same when driving the car, regardless the gear I'm in, i.e., when I go up to 3000 rpm, maybe up to 3500 rpm, but then it seems to "smooth out" above that engine speed. Thoughts??

 

[Forzaguy]

I have a full sheet of gotta do's for when the temp drops into 2 digits.

 

[clescn]

Yes it does. It also does the same when driving the car, regardless the gear I'm in, i.e., when I go up to 3000 rpm, maybe up to 3500 rpm, but then it seems to "smooth out" above that engine speed. Thoughts??

a further question...would a malfunctioning VVT have anything to do with this issue? if so, how to diagnose and/or fix it? could I switch the two wires attached to the VVT or disconnect them to see if anything changes?
Thanks.

 

[Tony Hladun]

My S4 rattled at 3000 till I did this... The studs holding the exhaust heat shield have a portion with no treads. You need to use several washers to build up thickness so the nut doesn't seat on the untreaded portion and then not apply sufficient pressure on the shield. Your engine will sound much better!

 

[clescn]

My S4 rattled at 3000 till I did this... The studs holding the exhaust heat shield have a portion with no treads. You need to use several washers to build up thickness so the nut doesn't seat on the untreaded portion and then not apply sufficient pressure on the shield. Your engine will sound much better!

Thanks, Tony. I'll give that a try.