91 corolla mysterious pop-corn noise?

[billsif]

1991 Corolla
140,000 miles

a few months ago i started hearing this occasional clicking/popping sound while driving. it also happened occasionally while just sitting in the car with the engine off if there were strong winds, just an occasional light "...pop [or tap]..." as if someone swiftly and lightly tapped their finger on the lid of a shoebox or something, but possibly more of a rubber/metal grinding to the sound.

while driving, if i put my foot _under_ the brake pedal against the floorpan area, whenever the tap occurs it seems to be felt right beneath my foot on the other side of the floor board, but its hard for me to see underneath there when i get out of the car.

recently the noise has been happening more frequently while driving, to the point that now as im backing out of my driveway and driving down the road (at any speed) the clicks/taps/pops whatever you want to call them, happen a lot, like whenever the road isnt perfectly smooth.

if you are outside the car and put all your weight down on the passenger side of the hood/wheel well, and then let go suddenly, there's no noise, but if you do the same thing on the driver's side, after you let go and until the time the car stabilizes itself you can hear faint rapid tapping that is exactly like the sound im hearing ...pop pop poppoppop..

i really dont know much about suspension at all - what could be causing this noise? ive been driving like this for a while now and i dont know what it is, im just troubled because it seems to be getting worse.

i just had the rear struts replaced because one broke, but had never noticed any noise come from the rear of the car. after having the rears replaced the noise in front (driver's side) was either unchanged or possibly got a little worse.

any ideas would be greatly appreciated, or anything i can do to check this out some more or any cheap fixes.. anything.

if the shock is damaged on just the one side could i feel that firmly tapping against the floorboard directly beneath the pedals? (doesnt seem to be farther to the left or right than that when i slide my foot around to feel for it - directly under the pedals)

thanks,
bill

[tashirosgt]

It's hard to think of anything that would make such a noise while you were sitting in the car with the engine off. Sometimes the manifold makes a metallic popping sound as it cools. This is harmless. But you don't feel that doing anything through the floorboard. So perhaps we are dealing wtih two different noises. One suspect is the "half axle" on the drivers side. There are many threads on this forum about these, also treated as the topic of "CV joints" since those joints are on the axle. Jack up the car and trying turnning the tire and see if you hear a popping or clicking sound. Also, while the car is jacked up, look in the engine compartment and check that your strut mount is not broken. The top of the strut (with the big nut on it ) will seem to be fallen into a hole if it is. You can compare the appearance to the strut on the other side. With more difficulty you can crawn under the car and inspect the rubber bushings on which the "control arm" pivots. There are many more suspension parts. If the gear shift rocke noticeably while your engine is idling, it might be a bad motor mount.

[toyomoho]

Have someone push and pull the car up and down and see if you can fine-tune the location of the noise.

[silkydraws]

Ball joints pop quite often when worn. It's worn a groove into the ball and pops onto/ of of that groove as susp. moves. Jack up suspected wheel and see if you get movement. Or just replace, it's time anyway. Ball joints fail and when they do it usually amounts to a lot of body damage not mention the danger of losing control of vehicle. Have a shop that knows front ends well if you don't want to jst put a new one. Most of the plder cars I pick up tho have some scary looking ones on them after 150K , specially if they've been driven down bad roads. I've also had some that just clicked whenever you enter/ exit vehicle then the shop detected no movement. Once out tho the wear was evident.

[billsif]

I just went outside and pushed down on the passenger side fender a few
times.

Nothing, then a hissing sound when the car came back up,
nothing, then the same hissing sound
nothing, then a quiet pop from the driver's side.



Then I went over to the driver's side and pushed down.



If I push down and just let go, there is a hissing sound with a quiet
pop. If I push down and let go gradually, on the way back up: POP POP POP
POP!


I guess it's definitely the strut or strut mount.



How can I tell the difference?



The part that's visible doesn't really look too rusty, but all four
wheel wells are very rusty. The bumper is so rusty that one of the mounts rusted through and it's hanging on one side.



I'd just like to know if I can get the mount replaced or if I have to
replace the whole strut.



On the rear struts which were recently replaced, the bottom "cup" that
holds the spring rusted out and the strut ended up resting on the top
of the rear tire! And wore away a lot of the rubber driving it to get
fixed.


Now to pin it down to the strut or the mount.
And figure out how much it's going to cost to get fixed

Is it absolutely necessary or could I keep driving it like this?


Thanks Everyone,
Bill

[tashirosgt]

You can inspect the strut mount plates by opening the hood and looking at them. They are held to the body by 3 nuts. The center of the strut rod is held to the plate by a large nut in the center. (DO NOT REMOVE THE CENTER NUT since this lets the spring uncompress.) Often the plate breaks in such a manner that if you jack the car up, the top of the strut rod is not held up by the plate and it and its attached nut drops down.