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View Full Version : Why does my car sound like its cooking popcorn


ridin4jesus
09-25-2007, 10:54 AM
so last week i changed the oil and the valve cover gasket and oil filter. and now my car is doing this, it sounds like its cooking popcorn under the hood, the sound i think is coming from the intake manifold area, and if i rest my hand on the automatic shifter i can feel the rattles, any help?

daryl337
09-25-2007, 11:36 AM
I can't think of anything that could happen by changing the valve cover gasket and doing an oil change that would cause a sound similar to cam timing being off.

jrmiller84
09-25-2007, 11:49 AM
Valve covers make a hollow sound when they are tapped/rattled, kind of like popcorn.

My guess would be that your valve cover isn't completely bolted down. It may look like it is but it's probably rattling on top of the head and making that noise. One of the bolts may be loose.

This happened when I had my SOHC. The old owner ripped the threads out of the head and the valve cover wouldn't seal completely with the head. It would shake slightly and make that sound. As soon as I got the threads fixed the sound stopped.

Make sure you didn't strip any of the threads in the head. Don't tighten those bolts down hard at all. The threads pull out extremely easily.

daryl337
09-25-2007, 12:05 PM
hrm... I would think he would be able to tell if his valve cover is rattling around though... but of course I am making an assumption. :)

jrmiller84
09-25-2007, 12:32 PM
When mine was moving you could barely move it with your hand. It was unnoticeable to the naked eye. You could push down on it and lift up on it and unless you did it on the right spot and looked at it level, you wouldn't see that it was loose.

Not to mention oil eventually started slowly dripping from where it was loose.

ridin4jesus
09-25-2007, 12:41 PM
yeah i checked that already, and it wasnt it. you know it also sounds like a bolt that is stuck hopping around in the intake manifold, but i dont think that that could be it. Im just wondering if im going to need to take that all apart to find out why its doing that

drifting_changed_mylife
09-25-2007, 01:00 PM
ASK JESUS..............

what kind of motor cuz i know that the all my buddys that have ka's have the same problem. u should check under the valve cover, it might be the valves or the timing chain is hitting the suport under the valve cover

Dream240
09-25-2007, 01:21 PM
Your problem is under your valve cover.

Think about it. You do an oil change and replace the valve cover gasket, which means you had to remove/replace the valve cover. You either dropped something inside the head that you didn't notice or you loosened a bolt that you didn't re-tighten.

Now unless you fucked with something else that your not telling us about, that's where your problem is.

And the valve cover is not that hard to remove. Shouldn't take you more than 15 minutes...with a 5 minute coffee break.

Take it apart and stop asking questions. This is really simple mechanic logic...If you didn't have the problem BEFORE you messed with it and now you have a problem, then the problem is related to what you touched.

Now go fix it.

ridin4jesus
09-25-2007, 01:32 PM
i didnt drop anything into the engine, i didnt have anything to drop in there. And beside i drive this thing daily and it took a week for me to start hearing this. gonna check the timing chain senario, oh and its a dohc ka

Dream240
09-25-2007, 01:39 PM
DOHC valve covers are notorious for coming loose. Especially with bad motor mounts that rattle stuff loose within a short amount of time.

Just go out and pull the cover off again and go over the head very slowly and find the loose component.

And the timing chain thing is the timing chain guide rattle. It's a common problem that you should have heard about. Just remove both of those little buggers to be sure it's not them giving you grief.

ridin4jesus
10-03-2007, 07:52 AM
ok so nothing was under the valve cover and now its worse. I still have the noise but now when im at a light the car sputters, rpms are between .5 and 1, and one time it even cut off on me. Does this have something to do with the fuel injectors, the guy i got the car from said he had a problem with the first one on the rail, but when i got it it drove fine.

Dream240
10-03-2007, 08:49 AM
Time to go check for engine codes. the let me know.

daryl337
10-03-2007, 10:55 AM
I guess I would have to be there looking at it to tell you what it is, because somehow we went from "intake popping" to "loose valve cover" to "injectors".... which all usually make different sounds. a pop-corn popping sound from the intake is usually cam timing being off, a "clacking" sound from the valve cover is either the timing chain/guides or something loose, and a small "clicking" sound is injectors. T_T

steve shadows
10-03-2007, 11:20 AM
exaust leak...? maybe

daryl337
10-03-2007, 12:06 PM
yeh, but he thinks its coming from the intake side... although we havent really got a good description on where it is coming from.... haha..

ridin4jesus
10-03-2007, 12:16 PM
well i could swear its coming from some where around the intake manifold cause the sound is the most concentrated there, i can hold the oil filter and feel the popcorn like sound.

Dream240
10-03-2007, 01:57 PM
well worse case you have a failing lower engine. Does the sound ever go away? And it's been getting progressively worse right?

No engine codes?

daryl337
10-03-2007, 02:01 PM
you can feel it in your OIL FILTER? :\



Dream might be right on this one. Haha.

m91silvia
10-03-2007, 03:04 PM
maybe backfire...
constant backfire? :/
loose ex. mani?

ridin4jesus
10-04-2007, 06:52 AM
yeah the popping sound will go away but the it pops in and out, like the end of a popcorn bag in the microwave with the last few kernels. But this morning on the way into work it started making this moaning sound like a the belt was rubing on something and the rpms went from 1000 to 1500, then it sounded like it wanted to squeal on me as if the belt needed to be tighten then it went away. man this thing is gonna start talking to me in a minute

ridin4jesus
10-04-2007, 06:53 AM
oh and no codes when i checked

Dream240
10-04-2007, 07:56 AM
Sounds like your engine is failing. Might just be it's time... :(

ridin4jesus
10-04-2007, 09:40 AM
NNNNNNNNNNNNOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO:cry :
SSSSSSSSSSTTTTTTTTTTTEEEEEEEEEEEEEEELLLLLLLLLLLLLL AAAAAAAAAAAAAAAAAAA
LOL, oh well, she just went over 200k a couple of days ago
time to put her in the garage and ride my other 240:hsdance:

steve shadows
10-04-2007, 10:27 AM
Jesus probably got angry with you for jocking him so hard.

what was it? rod bearing? those are fun

ridin4jesus
10-04-2007, 11:53 AM
well i ride for him and no one else :2f2f: , and i aint ashamed.

ridin4jesus
10-09-2007, 08:25 AM
ok so yesterday i was ridin into work and the car cut off, so i put it in nuetral and go to start it and smoke starts coming out from the hood, so i push it to the side and check under the hood and apparently my alternator belt snaped in half. so im assuming that might have made the sounds from before, but anyone know about the smoke? i had it towed and changed all the belts and now it wont turn over, it will chuga chuga chuga but not start. anyone know if that is the starter or alternator?

Dream240
10-09-2007, 09:57 AM
Sounds like you need a new motor. Does it still make the popcorn sound? It the noise louder?

ridin4jesus
10-09-2007, 10:24 AM
it doesnt make any sound cause it wont start

Dream240
10-09-2007, 11:33 AM
i had it towed and changed all the belts and now it wont turn over, it will chuga chuga chuga but not start. anyone know if that is the starter or alternator?

It's prolly neither. Check your battery. When your alternator isn't working, your car will run up until your battery is drained, which usually lasts about 10 minutes. You should have had your battery light turn on BEFORE your car died. It's basically a charging system malfunction warning light.

The smoke could have been from the belt burning up. You might want to check your other belts, cause one belt snapping and taking out the others is common.

Really having a belt break on you is just plain poor maintenance. I've been driving for 12 years now and I've NEVER had a belt break. Sounds to me like a bad belt is the least of your problems. Have you ever even done a complete maintenance checklist on your car?

ridin4jesus
10-09-2007, 12:42 PM
well i know its not poor maintenance cause i changed everything when i got the car, the belt is only a month old, just a faulty one i guess, took it back and got another. I know the car needs some things but right now, i aint got no dough to fix the others.

daryl337
10-09-2007, 02:21 PM
I have had a belt fly off before.. but that was due to a AC compressor clutch locking up and letting things fly.

ridin4jesus
10-09-2007, 04:04 PM
ok so it wasnt a dead battery, i tried to just it but nothing. anyone think it is the starter or alternator?

projekt_s13
10-09-2007, 04:16 PM
Can you see any popcorn?? Check your throttle body for lodged popcorn, if thats good then check your muffler bearings.

daryl337
10-09-2007, 04:19 PM
To the op: check the starter using a screwdriver

To Projekt s13: Did you know that in the mid 70's GM actually called the little metal exhaust donut a muffler bearing? Straight from the manufacterers specs. :| lawl at that.


smoke coulda been from the blinker fluid getting on the manifold.. that can do it.



But seriously.. check the starter incase it has fried before buying parts. :)

projekt_s13
10-09-2007, 05:07 PM
haha, good to know.

I totally forgot about the blinker fluid, make sure its not leaking.

To the op: check the starter using a screwdriver

To Projekt s13: Did you know that in the mid 70's GM actually called the little metal exhaust donut a muffler bearing? Straight from the manufacterers specs. :| lawl at that.


smoke coulda been from the blinker fluid getting on the manifold.. that can do it.



But seriously.. check the starter incase it has fried before buying parts. :)

Z33dori
10-09-2007, 05:21 PM
you dropped a valve......

yeah i know because this just happened to me.

so now im on the looks for a SR swap........tho i barelt have any cash instead of throwing in another pos old Ka.

pr240sx
10-09-2007, 07:32 PM
You dont need a new motor, you need a new DRIVER

Pics or video will help

MudRacer
10-09-2007, 08:05 PM
HE probably heard a knocking sound from his DOHC KA. It almost sounds like popcorn but its actually a knocking sound.
Happened to my KA24DE 2 years ago. After a week of driving it just got worse. Took it to a mechanic, he said your engine is about to blow so dont drive it. Surely he was right. it sputtered oil everywhere and the engine blew and would never.......turn again.

if it wont turn, and its not your battery or your alternator, and the belts wont move. you need a new motor.

pics do help. video even better. a sound clip, genius.

ridin4jesus
10-10-2007, 05:32 AM
so how do i check the starter with a screwdriver?

daryl337
10-10-2007, 09:07 AM
Looking at the starter solenoid, you should see a few posts.

1 is on the "big side" where the bendix resides, and the other is opposite of that, where your power is coming in from your battery..


Using your screw driver, ground yourself to the nearest water puddle and lick your fingers... now touch the two posts together with your fingers and let the fireworks fly!



JK. Use the screwdriver to touch the two together.. if you have a good batter any a good starter, your starter will crank over. If you just hear a nasty grinding noise, your flywheel is not turning for a number of reasons... so your motor might have seized or your ring gear/starter teeth might be messed up.

If you dont get jack squat... you have a bad starter.