Old 1Zz-Fe Metallic Noise Under Part Throttle

Hi Corolland Masters,

Recently my old 1.8 1ZZ-FE VVT-i will develop continuous metallic noise when driving 80-110km/h. The noise might temporary eliminate if I release throttle and re-apply back (keeps regulating the throttle pressure). I found the power seems dropped after this noisy symptom surfacing. Mechanic suspected spark plug and V-belt issue, which after replaced still giving the same noise. I searched through some article and youtube, most people are showing rod knock noise or VVT-i noise on idle speed, but mine is showing noise only during driving under "part throttle". The youtube video on this link having exactly the same noise:

Any idea what's wrong before I visit another mechanic? Thank you.

Hi Corolland Masters,

Any thought on what possible causes of this metallic noise?

Thank you.

Very hard to tell what it is on that video AND the 1.4 4ZZ is a different motor with different sounds than the 1.8 1ZZ

The 1zz is a very noisy engine, and will have valve noise that is not harmful but will also have rod knock if the oil is neglected.

The 1ZZ has an issue where the rubber belt tensioner bushing fails at the hydraulic tensioner and it will rattle under light throttle, but then the mounting bolt can break when you try and change it. I was fortunate mine did not.

The Prizms have an issue the Corollas will not in that the clutch plate on the A/C compressor warps and rubs against the pulley and it sounds like a bad bearing. it makes a continuous or fast cadence metallic scratching sound.

You didn't mentioned model year, mileage, trim level, market, etc. Given your screen name - not sure if that refers to this car or what you had before.

I agree with K_Watson - this sounds like it could be coming from the belt tensioner / idler pulley / accessory pulley area. Has that telltale "rattling/knocking" noise when you hit a certain RPM - but usually, it happens when you unload that area - ie, that small window when you let off the throttle, possible during light throttle application).

If you are holding the throttle steady and getting this noise at speed - could be related to the VVT-i system. If the OCV (oil control valve) is not working or the filter associated with the OCV is clogged, VVT-i operation will not be optimal - could see increased engine noise at partial throttle (engine knocking) and loss of power across the powerband. This is more likely the case when the engine is warmed up - if the noise is less noticeable or not there when the engine is cold.

Another possibility is a failing or dying upstream O2 sensor. This case, it is barely working, so as to not trip a DTC (diagnostic trouble code) - but not functional enough to ensure good driveability and operation. Usually a sudden drop in fuel economy is a sign of a dying O2 sensor - but not always the case. You didn't mention the miles on the car, but these are generally designed to last about 100K miles, anything past that is gravy.

The mechanic will have to do a pretty throughout diagnostic and not fall in that rut of swapping parts on your dime, to "figure out" what is wrong. Got to check the basics, try and isolate the noise source: Assuming they already checked the most obvious stuff, Fuel and Fire

- fuel: make sure fuel supply is good (good pressure to injector rail, injectors working, fuel pump keeping up with demand, etc.), also need to check on the induction system (air supply) - no cracks in the intake system, no vacuum leaks, MAF sensor working, IAT reading correctly, throttle body inspected, TPS sensor working, etc.

- fire: make sure that ignition system is producing a good spark, plugs are good, coil on plug igniters are good, system reading the crank position sensor correctly, etc.

If they didn't check that - go somewhere else. If you can't baseline the system, can't effectively diagnose the problem. The tech will also need access to a Toyota Techstream or similar test tool - this will allow them to command and interrogate sensors - see if they respond like they should (ie, the VVT-i system).

Hi All,

The car is year 2004 corolla altis 1.8 1ZZ-FE, automatic transmission, from APAC Malaysia. Currently it has 78k miles on it. I did not record down the sound but that youtube video has the best reflect of the metallic noise I'm currently encountering.

I can't detect the metallic noise when looking at the engine bay, engine was noisy when increasing throttle (yes this is 1ZZ-FE) but not metallic noise. Looking at the tensioner seems smooth without rattling when playing with throttle.

Yes, the car seems to loss its "usual" power and engine was little struggling to rev-up since this metallic noise surfacing (used to be rev-happy engine). I noticed it usually happens after engine has warmed-up to operating temperature, around 2400rpm to 3400rpm (I did not test higher rpm as afraid the engine might break during the constant noise). It sounds like knock pinging/detonation on other car, but I'm surprised it could stay long unless I release throttle pressure. I suppose there's knock sensor which should've reduce the ignition timing?

One thing I found yesterday, there's some oil stain on the OCV. not sure it was leaked through the head gasket or OCV itself. Was leaky OCV a common issue? I've cleaned up the area, let's see where the leak comes...

So today i went another mechanic to have further checking... he couldn't hear the noise as it's happening "intermittent". He used diagnostic computer to check for error code, none showing up. He then proceed to test the VVT by activating it during idle, engine will stalled after brief hesitation. According to him this is normal VVT operation. He also test around a few settings such as idling speed, 580rpm to 2400rpm. I was amazed the engine still idle even with 580rpm.

He opened up the OCV valve and OCV filter. OCV filter looks ok, wasn't clogged. Cleaned it with some solvent and sprayed with air-gun. When going home I hear the noise still coming back occasionally...

Now I'm worried it might be some serious engine problem. Read this forum found a member having similar symptom but bearing was gone after months...

Doubt it is a bearing going bad - that would make for a very obvious knocking noise that varies with RPMs (ie, sound is not intermittent, always there, noise quickens as RPMs rise, slow down as RPMs fall).

Yours sounds more like typical VVT-i operation. The 1ZZ-FE is known to be pretty noisey, even under normal operating conditions.

Most found that switching to a different brand of motor oil can help quiet things down (or make the noise more obvious). I'm assuming the mechanic ruled out anything on the accessory side - ie, pulley bearings, idler pulley, serpentine belt tensioner, etc. Those are pretty common source of the ticking/rattling noise that can be heard under certain conditions. Quick test is to run the car without the serpentine belt. For short duration testing ( minutes ) - this won't hurt the car at all. But that will definitely tell you if the noise was coming from the accessories or belt side.

Hi fishexpo101,

I have sent my car to another mechanic. After a short drive, he suspect it could be sludge affecting the VVT-i gear. This require the cylinder head cover to be removed for further inspection...

One more thing is the alternator making constant "yi~~~" noise which directly proportional to the engine rev, i'm not sure if it also produce the metallic rattling.

For now I assume this issue was minimal and have no immediate impact to the engine's health, so I will ignore it until the issue more pronounced (to ease-up root cause diagnostic).

Although I haven't heard your alleged noise in particular, have you tried higher octane gasoline? Are you at near sea level? How much oil does the engine consume?

Hi fishexpo101,

 

I have sent my car to another mechanic. After a short drive, he suspect it could be sludge affecting the VVT-i gear. This require the cylinder head cover to be removed for further inspection...

One more thing is the alternator making constant "yi~~~" noise which directly proportional to the engine rev, i'm not sure if it also produce the metallic rattling.

For now I assume this issue was minimal and have no immediate impact to the engine's health, so I will ignore it until the issue more pronounced (to ease-up root cause diagnostic).

Hi oldaltis,

I know it has been a while since the last posting here. Could you pls advise if you managed to figure out what was causing the problem? I am struggling with the same problem with the same engine.

Thanks

Hi, were you able to figure out the root cause of the issue ? I'm having a corolla Altis with 1.8 1zz FE engine and exactly the same issue as you described above.