Condensing search results for "rattling noise"

[brink]

So, I have this rattling noise in my car. Doing a search for "rattling" or "tapping" gives me a lot of possible things to check out, this thread is to sort of condense them so that I can know what to look for tomorrow. Maybe a bit premature, cause I haven't taken a stethoscope to the motor yet to isolate where it's coming from. That'll be tomorrow.

5sfe in 2000 Camry. 46,000mi (approx 69,000 km?)

• Here's the problem:
• Engine has a rattling noise that by ear appears to either emanate from the general valve cover area or quite possibly from the exhaust area.
• The rattling occurs on acceleration but doesn't appear to rattle during deceleration.
• It rattles regardless of where the clutch is.
• It rattles if I just rev the engine. It sort of goes away after revving past 4,000.
• It's most evident when there's load on the engine, such as driving versus parked.

• Things that might relate to this:
• I just changed the fuel filter several weeks ago.
• I've been running 87 octane lately, haven't tried a higher octane yet; I just noticed this today.
• I was a dumbass and didn't check/change my oil even though I'm about 600mi overdue (that's going to be its own thread, and let me tell you it's going to be upsetting).
• Looking into the oil fill hole you can actually see sludge buildup (I switched to synthetic TONIGHT).
• I don't recall blowing any shifts or grinding any gears lately.
• The rattling occurs regardless of engine temperature.

• Possible problems based on TN search:
• Bad gas/low octane
• Sticky lifters
• Something called piston slap (?)
• Cracked exhaust
• Timing is off (slipped or tensioner)
• Some kind of loose piece of shielding just a'swayin' in the breeze

What else should I look for tomorrow?

[kocho]

600 miles overdue for an engine oil should not be an issue in regular driving: 600 miles is only about 10% of the factory recommended interval (for '00 is 5,000 to 7,500 miles with regular oil).

Regarding the sludge: are you sure you see sludge? The 5sfe engines have coating on the metal under the oil cap. Mine ('00 LE) is black, my friends is silver-ish. Neither of us has sludge (and I've been using Mobil 1 Synthetic for the past 40K miles or so). Take a second look - if you can't scrape some of it off with a wooden or plastic stick, then it is not sludge (take care not to drop any debree in there while trying).

[brink]

Except I also autox and I haven't been changing after events.

[rezzle]

Is the noise cyclical? If so think about exhaust leaks too. Exhaust manifold. missing heat shield bolt, loose spark plug, all can make odd sounds at times.

[idrivemyself]

that can't be healthy... try doing a complete flush to clear some of that crap out, then refill with synthetic.

[brink]

I'm thinking it's lifter tap and it's probably caused by the sludge as discussed here http://www.toyotanation.com/showthre...threadid=21603

The noise appears to be cyclical, it's hard to tell but it seems to get faster as you rev the engine. The fact that it disappears around 4 grand is confusing though. Had a moment of fright when one of my friends said that it sounded like a rod bearing, but it would get louder or at least be more constant when you quickly rev the engine. If you just gun it when parked there isn't any noise.

As an aside, those stethoscopes are neat! You can hear the injectors squrtin' and stuff!

[kocho]

Man - that's ugly! Try synthetic after a flush - if your seals are good and your engine doesn't leak from it, it should take care of future sludge.

I used to do my changes originally with regular 5w-30 at 7,500 miles, and noticed some oil thickening when changing it. So I switched to synthetic at 5K intervals and no problems so far... But I do not race either :o

Originally posted by brink
Except I also autox and I haven't been changing after events.

[brink]

FWIW, my particular rattling was a rod bearing.