Rattling from under the hood.

[(K)]

So I got some clickity-clakking going on under my hood. Yesterday I thought something was odd with the car when I started it up, but by the time I got to the hood latch everything just seemed normal again and the sound went away. Today the sound became more pronounced and doesn't go away at all. I can hear it at idle pretty clearly. When I step on the accelerator it doesn't get louder or faster at all, it actually kind of gets drowned out by regular engine noises.

I'm thinking it's the car telling me it's time for a tune up because I'm at 94,xxx miles right now. I assume the original spark plugs are in there but I wasn't too worried about them because supposedly 2AZ's came with Denso Iridiums (it's about time for a change anyway). I thought about it being a heat shield but it's not that sharp metallic clanging sound, plus it's coming from towards the intake side as opposed to the exhaust manifold side.

No CEL, no apparent loss in power, everything seems a-ok but that sound is driving me nuts because I know it just ain't normal. 2002 4 cyl. btw.

Any other ideas/suggestions?

[5842solara]

depends what it sounds like precisly.

you could try changing oil and using thicker weight.
-my dad had rattling and he changed to thicker weight and it went away

if you know someone at a shop, ask them if they have BG products. they are really good. i forget which one but it cleans out the injectors for sludge and gunk and what not.
it might be MOA. not sure.
here in hawaii only shops sell that, i think few stores have it but kinda expensive.

[dan99solara]

do toyota's 90k-100k tune up / preventative maintenance whatever you want to call it. change oil, filters, plugs, timing belt, check water pump, etc etc etc.

[Chinky420]

well, if it doesn't change the clicking with accellerating/revving, then it's probably nothing related to your drivetrain.

*PROBABLY*

does it correspond with any of your accessories (air conditioning maybe?)

sounds like quite the pickle tho.

[(K)]

I just finished the usual maintenance plus spark plugs on Friday. The sound hasn't gotten any better. It's actually got this clacking-ness to it as opposed to a metallic dink sound...if you get my drift. Definitely metallic, most easily heard from the driver side corner. It's most likely not drivetrain related like you said Chinky.

I'm starting to think exhaust related though. I'll bring it to the dealership while I still can. Might be a combination of things because it doesn't seem very isolated.

Thanks for the input so far though.

[(K)]

Just for future reference in the archives or something:

I narrowed the sound down to the intake area behind the block and towards the firewall. Fuel Injectors. So I popped in a bottle of fuel injector cleaner and the sound went away after an empty tank.

Also there's a small hole in my exhaust towards the cat 1 area...darn you New England weather. Surprisingly it sounds pretty decent, time for some headers!

[gnegroni]

Just for future reference in the archives or something:

I narrowed the sound down to the intake area behind the block and towards the firewall. Fuel Injectors. So I popped in a bottle of fuel injector cleaner and the sound went away after an empty tank.

Also there's a small hole in my exhaust towards the cat 1 area...darn you New England weather. Surprisingly it sounds pretty decent, time for some headers!

Wow, so the injectors were that clogged they became super noisy?

[(K)]

I know it sounds a bit farfetched and I can't say for sure that it was a clog, but the first thing I thought of before starting to do any real work on the car after figuring that it was the injectors was to get some fuel injector cleaner.

Surprisingly, it took care of the job. Maybe the injectors just needed a little extra lubrication or maybe it was just coincidence. Whatever the case, the sound went away and hasn't been back for a week.

My suggestion though, if you ever get this problem, might as well invest ~$10 and pop some in your tank before doing some serious work. You don't really have much to lose besides the price for that bottle.

Which reminds me, I should have mentioned it to the dealership this weekend when I brought it in for an inspection...

[gnegroni]

I know it sounds a bit farfetched and I can't say for sure that it was a clog, but the first thing I thought of before starting to do any real work on the car after figuring that it was the injectors was to get some fuel injector cleaner.

Surprisingly, it took care of the job. Maybe the injectors just needed a little extra lubrication or maybe it was just coincidence. Whatever the case, the sound went away and hasn't been back for a week.

My suggestion though, if you ever get this problem, might as well invest ~$10 and pop some in your tank before doing some serious work. You don't really have much to lose besides the price for that bottle.

Which reminds me, I should have mentioned it to the dealership this weekend when I brought it in for an inspection...

The dealer will probably say they were going to offer the $70 injector flush which could have provided better cleanup, but its really not necessary. A bottle of fuel injector cleaner every month is more than sufficient.