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صدای زنجیر در استارت سرد تویوتا
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it can be helpful to simply bump the starter one time for a split-second, which will likely cause the locking-pin to engage in the hole of the housing, as it should have done when the engine was last shut-off.
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صدای زنجیر کوتاه در شروع استارت سرد تویوتا :
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Engine Rattle Noise Upon Cold startup
It's a known fact that some modern Toyota vehicles, with Toyota's VVTi cam gears (or phasers, according to Ford motors), have been known to make such rattling noises, on start-up anytime the engine is cold.
This problem, has been diagnosed mistakenly in some climes, to mean, a bad engine, that needs urgent replacement.
Some have also diagnosed such noise on start-up, to mean, that the oil pump or connecting/crankshaft bearing caps and/or crank journals are failing.
With the cost of goods and services increasing daily, motorists would be happy, to get an alternative to engine replacement, if such situations presents itself.
Some symptoms of this problem?
1. Well, on start-up, when the engine is cold, a rattling noise comes from the top cylinder area of the engine.
If you're not careful, would mistaken this noise for engine knock.
2. No matter how you keep changing engine oil viscosities, thinking, a more viscous oil would make any change.
3. The noise gradually increases, and could lead to engine damage(siezure), and engine replacement.
So how do you fix this?
1. The ultimate fix to this is to order a BRAND NEW CAMSHAFT VVTi gears or phasers for the intake and exhaust.
Ensure the part number on the gears matches that recommended by Toyota.
CASE STUDY
Car: Corolla 2008
Transmission type: Autos
Engine capacity: 1.8L
Customer complaint:
At every cold engine startups, rattle noises occurs, and disappears, within seconds, until, another cold cycle start-up is required.
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The top of the engine has nothing to do with timing chain on start-up. If you have a rattle at start-up you have some worn parts, plugged up oil galleys, or your oil is too thick for the temperature you are operating in.
Short of running the engine low on oil you would need to have a leak in the system so cracked pickup tube or some other leak in the oil circuit to get a dry start. This is also why when one changes the oil you should not empty the pan and remove the filter at the same time that is like taking your finger off of the stray full of pop as a kid. That is also why you should always prime a filter when ever it is doable. So I always drain the oil pan first and refill before I break the filter lose. Toyota's are not as bad as most GM engines but they too do and can lose prime and you will hear rod nock or timing chain rattle when this happens when changing the oil.
If I had to guess I would guess worn out timing chain tensioner as my first guess but it could be sprockets, timing chain, guides etc......
Nothing wrong with a timing chain if you keep your changed a timing chain can last forever especially compared to a belt! A timing chain can last 500K miles with just routine maintenance your lucky to get 90K miles with a belt before most OEM want it and all it's hardware changed.
Never and I repeat NEVER put Lucas or No Smoke or Motor Honey in a 2AZFE it will plug up ring packs that are already poorly designed.
I would pull the VVT filter screen on the back of the block and see how it looks. If you see varnish or sludge clean the filter screen and re-install. Maybe consider giving 2 bottles of Auto-RX+ a try.
If you are not already using a 0W30 or 0W40 I would switch to that first and see if that helps!
Just like a noisy lifter you could try adding a bottle of MMO Marvel Mystery Oil or a Bottle of Risolene and see if it goes away. I have never seen MMO or Risolene cause any harm to an engine even the Used Oil Analysis when MMO is left in for an entire oil change at 20% or 1 quart swapped out or added. I would not expect either to do much but I have seen them take care of a noisy lifter, stuck valve or sticky tensioner before!
When I was in flight school the head A&P Mechanic swapped a quart oil oil for a quart of MMO in every car and truck he owned and swore by it. I have known a lot of old collectors with MMO Auto-Oilers on engines and again clean long lasting machines. I have better stuff than MMO. It is so cheap and so gentle and has such a long track record of doing no harm if I had a noisy lifter or the like and I was not set up like an industrial chemist and tribologist I would give it try. A lot of 2AZFE owners have been able to temporally reduce oil consumption if caught when it starts by adding a bottle of MMO each oil change. So while there is better stuff for sure it is something to keep in mind.
Even a tiny bit of varnish or carbon deposits in todays lubrication circuit and do things in. I have seen people replace a part just to have the problem return quickly because of a dirty engine. An engine that would have been clean enough to not cause any problems 20 years ago just wont do today. That is why new carbon, sludge and varnish solutions have been devised over the last 20 years. An engine that some might say is done and needs to be rebuilt can today in the right hands often be made fine with the right chemistry and process to clean out deposit
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.The first cold start of the morning ، some Toyota and Lexus V6 owners, especially those who have the 2.5L or 3.5L V6, notice a loud rattle the first few seconds after startup.
The noise disappears after the car builds oil pressure.
The most common cause is the variable valve timing camshaft gear assembly leaking down oil pressure as it sits.
What is this part and what should you do if you experience these symptoms?
The variable valve timing system allows the engine to benefit from timing that can change as the engine dictates – it’s like having many different styles of camshaft at the ready. At a steady freeway cruising speed? The variable valve timing acts like an exhaust gas recirculation system, helping to reduce engine emissions. Going for a spirited drive? The timing ramps itself up, aggressively advancing the intake cam to help speed air and fuel into the cylinders to give you the most powerful combustion it can muster. Both intake and both exhaust camshafts are independently controlled by individual valves that flow oil into and out of the camshaft gears, advancing and retarding the camshaft’s timing as dictated by the engine’s computer. Oil pressure is used to move internal phasers in the cam gears, allowing them infinite variations of position. Below is a photo of a variable camshaft gear opened up:

The problem lay in the construction of the intake cam gear assemblies – in some cases while they sit unused (engine off) they bleed oil pressure back into the engine. This is not a big deal when they sit idle, but upon startup they are starved of oil (it all leaked out back into the oil pan!) until the oil pump can send them pressurized oil to take up the slack.
This the rattle noise you hear – the internal phasers being knocked about without much oil to cushion them.
The problem led to enough failures that Lexus’s repair bulletin was upgraded into a full blown recall for some 3.5L direct injection engine (recall DLG). For reasons unknown these gears were more likely to fall apart and throw debris. Other versions of the engine with these cam gear can also have issues with check engine lights and ticking noises from the engine while it runs. Toyota repair bulletin T-SB-0094-09 covers this more in depth (it’s a big procedure requiring engine removal)
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camry maxima تعمیر تویوتا ماکسیما:
Toyota cold start chain rattle :
I have a 2010 RAV4 Sport, with the 4 cylinder 2ar-fe engine. 220K miles.
Quick recap (see the above link if you want more detail) : I have the classic 2ar-fe rattle upon cold-start. I had two mechanics tell me it was timing chain rattle. I had my mechanic replace the timing chain, tensioner, guides, etc. The chain was stretched and tensioner was not functioning properly and the guides worn. However, the noise did not go away and last 3 to 4 seconds now, as opposed to to 1 to 2 seconds before.
My mechanic says it's probably the vvti cam shaft gear, and that while it's annoying, it will not cause harm. He would basically have to take the timing cover off, just like he did for the timing chain replacement, for pretty much the same cost.
I've checked gas mileage, and it's right around 19-20 mpg (city), pretty much where it's always been.
I had to save up for several months to do this, and had other family vehicle repairs this month as well. I'm pretty much out of money at this point, and it would take me several months again to save up to do this. I'm consoling myself with knowing the timing chain, etc had to be replaced anyway. I do kind of wish I had known about the vvti cam gears. But oh well...
I've found two threads in which it was suggested that this rattle is harmless. And one which says it could be catastrophic.
Is there anyone knowledgeable here who can tell me how serious this is?
Thanks for any help you can give.
About 5 yrs ago I "fixed" a VVTi rattle in my Toyota 4 cyl by switching to Mobil One High Mileage Oil. The rattle had been present for at least 2 years before I switched oil. After one oil change.... and a few thousand miles, the early morning rattle disappeared... I had changed the chain tensioner about 6 months before w no improvement in rattle.
My "assumption" is that the rattle was due to some clearance issues (clogging) in the VVTi mechanism....I had exclusively used Mobil One Synthetic for at least 100 k miles before this.....
If I had the same issue today , I would try Valvoline "Restore and Protect" for a couple of oil changes and say a prayer that it would address the issue......
I have 2013 corolla and I’ve changed timing tensioner, timing, chains timing chain guides, both VVT gears torqued to specs and put mobile one 520 and it still rattles at start up .I’m just going to roll with it it’s got 160,00 so.
Well i took someones advice on this thread and just tapped the starter a couple times before i actually started the engine (2011 2.5 I4). And it started very quiet! First time that has happened. Every cold start, it clatters.
So that tells me it has nothing to do with oil pressure at the VVT device and it's probably a mechanical issue like the locking pin NOT in it's right place after engine shut down..
Glad that tip worked for you. It [more than likely] confirms that your clatter/rattle, lasting approximately 1 second at cold start-up, is your VVT controller. At engine shut-off the spring-loaded locking-pin is supposed to latch into a hole in the side of the housing. That locking-pin engagement event is what is not happening all the time.
When the engine is stopped, in order to improve startability, the intake camshaft will become the most retarded state because of the external force such as the valve spring force. At this time, the locking-pin fixes the housing and the movable vane in the controller. After the engine starts the locking-pin is released from the housing hole by hydraulic pressure.
In all likelihood the locking-pin fails to lock into position at many other times also, other than at a cold-start, but the 1 second rattle or clatter sound is not really heard or noticed because the engine had only been shut-off for a short time before the engine was restarted again, and the VVT controller still had adequate oil within the controller to muffle or buffer the sound of the vane moving within housing. After the vehicle sits parked overnight (or any lengthy period of time) the engine oil in the VVT controller (housing/movable vane) naturally drains back to the lowest parts of the engine except of course for a thin film of oil and random little puddles of oil in valleys and crevices here-and-there. There is no anti-drain back type of valve in the VVT system to keep it full of oil. That said, when a cold-start is made is when the VVT noise is heard 'if' the controller's locking-pin had failed to engage in the hole of the VVT's housing when the engine was last shut-off.
To hopefully correct this fault (when it happens) it can be helpful to simply bump the starter one time for a split-second, which will likely cause the locking-pin to engage in the hole of the housing, as it should have done when the engine was last shut-off.
Hope that helps explain what is happening, and why a quick starter bump usually helps
There are DTC's the ECU can set when it detects problems with the VVT system. My car has made this rattle sound since I bought it and nearly 100,000 miles later, it is identical. I am not convinced that it is a real problem because the engine performs flawlessly under load...it could be that normal wear simply causes this sound to appear. I have not found a definitive answer on the internet, only a lot of complaints on cars that otherwise run perfectly. Until I see a CEL illuminate...I'm not going to bother with my car, at least.
Just to add to this thread. I have this rattle and went to Toyota and they performed the TSB repairs. Intake and Exhaust CAM GEARS replaced also the chain.
The rattle is still there, so I think the pin that everyone mentions is the issue and they have not taken care of the problem.
So there is a VVti Controller that should be replaced when this TSB is done to ensure the 1 second rattle is gone?
I have a 2011 Camry SE with 43K miles on it. On some days its a second that the rattle lasts and some days its a 2 second rattle, then its quiet.
Thanks
Your "CAM GEARS" that was replaced IS the same thing as the VVTi Controller. I am glad that changing the gears did not make your clatter go away because I was about to bring my 2011 LE I4 in for the same thing. I just as well not have them touch it if changing BOTH gears does nothing. That is SAD! for TOYOTA!!!!