01 Corolla engine question

I know there are about a million different probabilities with this particular question, but figured I could at least get a few thoughts on the issue. I have a 2001 'Rolla CE with about 120K miles, stick, 1.8. It's making quite a knock/Rattle in any gear and only under acceleration or holding steady at about 2-4K rpm. The only way I can accurately describe the noise is marbles in a tin can it's a high pitched rapid metallic noise. it also doesn't burn excessive amounts of oil (no more than these engines are known for anyways) I have a few ideas as to what's wrong but figured the collective mind here could possibly shed some light.

Spun a rod bearing. Louder the more throttle you apply?

It does seem to get a touch louder through the 2-3K rpm range. That's kind of what I was guessing at as well.

Or a timing chain problem? Rods tend to go knock-knock-knock. Timing chain tensioner out sounds like continuous grinding/rattling.

Seeing as how a tensioner is $20 on rock auto and appears to be a simple swap I will try that first.

Glitter in oil? If you spun a bearing there will be. Ever overev it (7000+)? Check for some failure in the accessory drive yet?

Chain tensioner is a spring loaded mechanical ratchet type IIRC, I don't think they're known for going out. Should be able to check by popping the valve cover off and rocking the crank back and forth, should be very little if any slop (maybe a degree or two).

Haven't checked the accessory drive for any failures yet. I did not see any glitter in the oil, not sure if it's ever been over revved, I bought it with around 110K miles and it's been doing that since. I need to do the valve cover anyhow so I will take a gander at the tensioner. I held it at 4K rpm last night and the noise went away temporarily for a few pulls through the 2K-4K rev range not sure what that means, if anything. I appreciate the suggestions thus far!

Cut the oil filter apart and see what's inside.

I'm still leaning towards timing chain if it is internal. Also,water pump or other accessory is a possible.

"marbles in a can" could be spark knock or carbon rattle.

Probably not.

Give it an Italian tune up for truth.

I've given it the Italian tune up a few times, seems to quiet it down for a moment but always comes back.

Well, that rules out an internal bearing.

In reply to Kenny_McCormic: Just wondering, how does that rule it out? I'm no expert in this area.

Unless your definition of "Italian tuneup" differs greatly from mine (lots of WOT and shifting at red line), such activities will definitely lead to a thrown rod if you had a spun bearing.

Ah, I gotcha. I didnt shift at red line, but was WOT through 3 gears shifting at around 5-5.5K

Heat shield rattle, most likely.

FWIW, I've had a belt tensioner make some nasty marble noises before. Although that was down around idle-2000rpm ish.

I've considered a heat shield rattle, guess I need to get Jeremy Clarksons favorite tool out and see what I come up with.

In reply to ProDarwin:

Good point on tensioner, both the idler bearing and pivot bearing may be suspect.

Really should pop the belt off and give everything a spin/wriggle.

I think there's only one heat shield under the hood, on the exhaust manifold.

Bringing this back from the dead. I checked all heatshields and did the timing chain tensioner and the noise is still very prevalent. Could this be valve noise? Gas mileage is still in the 30s and oil consumption appears normal (normal for a corolla anyways)

Did you check the accessory bearings? A mechanic's stethoscope is handy here, especially if it will do it parked in neutral.

thedanimal wrote: Bringing this back from the dead. I checked all heatshields and did the timing chain tensioner and the noise is still very prevalent. Could this be valve noise? Gas mileage is still in the 30s and oil consumption appears normal (normal for a corolla anyways)

I had one with valve clatter due to oil starvation, but that was at low rpm. You could have anbelt skippingand causing the pump to fail i suppose, but that seems off.

I'll take a good look at the accessories this morning, thanks for reminding me I do have a mechanics stethoscope. i may just change out the belt just to eliminate variables, seeing as they're cheap. Thanks for the answers gents.

Well, I changed the oil this morning. It's got a fair amount of metal shaving, I took the stethoscope to a few accessories and none made the noise I've been hearing. I know metal shavings are never a good sign, does this mean the engine is on it's way out?

At the very least, youve got valve junk. Probably a spun bearing. My cooper s did just that.

Metal in the oil=dead. Pour a bottle of STP (will limp a little longer that way) in it and start engine/car shopping.