Grinding noise on start up

[DJKOR]

Probably late to chime in on this, but there is some discussion that can be found over on the Aurion board too.

Is this kinda the sound you were referring to?

If so, here's a post I prepared earlier from a while ago before it was really defined as to what the cause really was. It gives a bit of insight of how the noise is produced however:

I guess we were right. Dave and I had this one on our minds from when we first thought about it. Since you are the second person to report that it is being changed under warranty, maybe there is some more hope for others that are getting the issue.

I dont think it is piston slap, more like a timing chain rattle or maybe something in the vvti mechanism.

That's what I'm thinking. It seems to be coming from the upper part of the block. It's similar to the sound of that intake control valve closing, but more metallic. It just has me stumped.

Maybe it really is the VVT-i mechanism. When you see a video animation of it working, you can kind of picture how it can generate a knock/rattle sound if it doesn't have appropriate oil pressure in it.

The mechanism is like this for those that don't know:

Having a quick look at the service manual, maybe it ties in with the so called 'lock pin':

When the engine stops, the intake side VVT-i controller is locked on the most retarded angle side by the lock pin, and the exhaust side controller is locked on the most advanced angle side. This ensures excellent engine startability.

The oil pressure sent from the advance or retard side path at the intake and exhaust camshaft causes rotation in the VVT-i controller vane circumferential direction to vary the intake valve timing continuously.

An advanced angle assist spring is provided on the exhaust side VVT-i controller. This helps to apply torque in the advanced angle direction so that the vane lock pin securely engages with the housing when the engine stops.

When hydraulic pressure is not applied to the VVT-i controller immediately after the engine has been started, the lock pin locks the movement of the VVT-i controller to prevent a knocking noise.

[RICE RACING]

There is a real simple fix to this and it involves a little simple technique:

(Note: even my 2011 FJ Cruiser can sometimes have a small grinding noise for a nano second as listed in the linked thread)

Instead of turning off your engine at idle speed of 750rpm odd you simply lift up the engine revs to 2000rpm for 1 second and then while at 2000rpm turn off the ignition!

What happens is more than double the oil pressure is present and a lot more oil is forced into and around the VVTi mechanism. After adopting this shut down method I for over a week of daily driving have not herd ANY type of odd noise on a cold start of the engine, even after sitting for multiple days.

Try it! It does work and for sure keeps more oil in the upper end of the motor.

[DJKOR]

There is a real simple fix to this and it involves a little simple technique:

(Note: even my 2011 FJ Cruiser can sometimes have a small grinding noise for a nano second as listed in the linked thread)

Instead of turning off your engine at idle speed of 750rpm odd you simply lift up the engine revs to 2000rpm for 1 second and then while at 2000rpm turn off the ignition!

What happens is more than double the oil pressure is present and a lot more oil is forced into and around the VVTi mechanism. After adopting this shut down method I for over a week of daily driving have not herd ANY type of odd noise on a cold start of the engine, even after sitting for multiple days.

Try it! It does work and for sure keeps more oil in the upper end of the motor.

I'll definitely be trying this one; it certainly makes sense. My Aurion is starting to do this now (9,000km since last oil change... like clockwork) so it would be a good time to test it. Strangely enough, I only get it when I park outside when I'm out and about. I have never had it once do so when I am at home parked in the garage. Can't explain that one.

[boleh]

Something to do with ambient temperature perhaps?

[RICE RACING]

Well since adopting this shut off method I have never had any kind of this noise ever again, I even went away with work for a 4 days and came back to fire up RICEFJ and quiet as a mouse!

Try it..... it works for me perfectly.

p.s. I do use Mobil 1 5w-50 oil................ I recommend to anyone who is not an avid reader of my posts to ditch the econocrap oil weight Toyota recommend to meet emissions *at the expence of engine life!* and use a proper grade/weight of oil in their motors if they care about them.

[thinker]

Hi Guys,

I bought a used Kluger Grande 2008 AWD about 2 months ago from a private seller with 124,000 KM on ODO with almost full service history (just the 30,000 was not done for some reason). Recently I have started getting the above mentioned noise and I have tried the technique mentioned by "RICE RACING" but to no avail.

I went to Toyota and they said if it's the CamShaft Gear issue it could cost $2000 to $2500 as it's a 3 day job. Guy said the problem is there in these models.

Now if it's something that Toyota made with a fault. Toyota should be fixing it right?

Why the consumer had to face these costs?

I am taking the car to the Toyota Dealer on Wednesday to inspect ($120) if the issue is of the CamShaft Gear or something else.

I would appreciate if you guys can suggest what should be done in this situation?

Edited August 12, 2013 by thinker