With the car not running you can try moving the belt tensioner in and out to see if that replicates the noise. You'll hear it make a clickclickclick noise. In the early models there was an issue with the accessory belt tensioners from one of the mfgs. I don't recall which mfg.

As far as the timing chain goes you would have to check the procedure and specs for checking the chain wear/tension.

 

Well I ran it off with no belt. Noise is still peesent. If I rev it slowly from idle its super loud and fades away around 3500 rpms.... the chain is loose between the cam gears too... kind of strange... I took out the tct and it looks ok but do these get weak and fail?

 

It works off of oil pressure, what you are describing sounds like the lock on tensioner is broke.

 

Please show me where the Oil Pressure gets to the Tensioner..

Cap

 

What is worst that could happen when chain tensioner gives up? Mess the timing enough of getting valves hit to pistons?

Currently I´m not sure if I have broken tensioner and possibly something else, but it is suspect #1. I was driving in 3rd gear no problem, then uphill corner and I chance to 2nd. After lifting cluch I hear clanking noise and engine is missing around 100hp. This was on track, so lots of rev... Engine still runs, but no power and any revs over idle there is this clanking noise.

Haven´t done anything to car yet after this incident. Just getting funds to repair and trying to figure out what happened and what to expect when disassembling engine.

 

Slack between gears? Mostly likely means chain skipped and depending on how bad yes P2V contact. But not sure if this motor is interference motor.

 

1ZZ is not an interference motor but the continued running with a slack chain will cause the timing gear to jump enough teeth that interference will happen and then you lose the entire motor. Having experience with porsche 911's, this was frequent issue for an entire generation of cars. An oil passage may be blocked so that the tensioner isnt doing its job or there may just be a tensioner failure here. Either way it could be fatal to your engine if you continue to run it.

 

1ZZ is not an interference motor but the continued running with a slack chain will cause the timing gear to jump enough teeth that interference will happen and then you lose the entire motor..

Can you please explain what you are saying..

It's not an interference motor, but interference can happen?

From what I have seen in these motors, the Piston will hit the Valves..

I understand that to be an interference Design.

Cap

 

i took the valve cover off and the chain has alot of slack inbetween gears...

I had this exact same problem on my 20 K Re-Hauled motor.. When the Engine was hot, it'd rattle like an old VW Bug Motor.. So this last weekend I decided to take a look..

I ran the Compression and the Valve clearance.. they were all good..

I could see the Chain Slipper 'Move' when I'd Load the Exhaust Cam with a Wrench.. And I had more slack on the chain then I'd like to have.. but the new ( From the Rebuild ) Chain Tensioner was not 'Catching' on the next tooth yet..

I started to remove the tensioner, and herd it 'Click' to the next tooth.. So I put it back together..

Slack was back to where I'd like it.. and the Hot Rattle is now gone..

The Hot Idle is now more stable also..

Cap

 

Just be careful, I had this problem and the chain and crank sprocket snapped. I would recommend at LEAST checking the chain and associated hardware. The chain itself isn't horribly expensive. If it were me I'd replace it, the crank sprocket, and tensioner and make sure the guide and slipper look good and are secure.

 

If you do find parts broken or not to your satisfaction, I have engine parts for sale ie: chain, cams, sprockets, chain guides etc.

 

Interference infers in car context that any issue with timing belt or chain will cause valves to meet the pistons; but even non-interference engines if they get far enough out of phase will have interference. In my experience you will want to shut the car down as soon as you begin to have issues.

 

Untrue. A non interference engine, by definition can have the crank rotate thru 360 degrees without hitting any valves, even if they are extended fully. The 1ZZ and 2ZZ are non interference, except for when the 2ZZ is on the high cam, or if you have aftermarket cams with more lift.

Lots of people with non interference engines and timing belts just drive them until the belt breaks, as this doesn't cause any damage.

 

1ZZFE 2003 and later in Matrix/Vibe/Corolla is interference. Fact.

 

I'm having a similar issue as OP. I get a light knocking noise sounds like the head area from 3k-3700K at partial throttle. if i give it more throttle it goes away. if i do hard throttle from idle itll do the rattle from 3k-4k and goes away promptly at 4K. could the be from the OCV? please respond.

 

update: So i noticed the rattling sound gets louder and makes the sound at idle when the engine is at full temp.

 

Go to newcelica.org and search 'tractor noise' or 'OCV thread' and do some reading. There is an issue with the VVT controller (the intake cam sprocket assembly) that causes this issue. There have been some catastrophic failures if it is left too long as the bolts on the assembly can rattle loose causing all sorts of havoc.

Any threads there about 2ZZ engines with the same issue are relevant, the intake sprocket is the same for both engines.

 

In addition to this, be wary of timing chain issues.. I was not able to determine if my chain broke first, and then the crank sprocket, or if the sprocket failed and broke the chain, but either way it made similar noises. I checked all of the above and everything else I could think of only to have the chain and sprocket brake and ding some valves. If you can't figure out what the noise is otherwise, you are best served to stop driving it until you can at least check the chain for stretching and or replace it and the tensioner and guides. The chain breaking does not seem to be a super common issue with the zz engines, but if it does happen it's not a good day.