SiBro

12 hours ago, Britprius said:

Having research this further there appears to be a spring loaded plunger inside the timing sprockets that locks them in a retarded position until oil pressure pushes it out of the locked position. If the spring that pushes it into the locked position becomes week or brakes this could cause the mechanism not to lock when the engine is turned off, and to chatter until it is filled with oil. It would then work normally. 

I can see know other reason for the existence of the plunger, and know it should release at 21 psi oil pressure. This pressure could not be reached until all the space in the mechanism was full of oil.

There is a video on the tube that shows this on a Toyota engine, but the guy doing the video could not work out what it was for.

John.

thanks. do you know what is rattling, which part?

2 hours ago, is200 Newbie said:

I have experienced this with mine (but not as bad as what was heard in the video you posted) and John & John in their posts above are spot on when stating its the oil. Its an obvious issue but not one to worry about and sound worse than what it is.

You will sometimes have this when changing oil as the oil reservoir that John has mentioned is drained and the engine has no means to fill it without turning on - when turning on it will rattle a bit (for a second if that)

I got rid of mine after regular oil changes using an engine flush (Wynns) each time - oil changes I do every 6 months but use the right oil (5/30). You will probably get it if the cars not had the necessary oil changes - check the colour of your oil and I will bet its black which is a sure sign it needs changing. 6 months use of Magnatec when changing the oil will see the oil a dark tea colour (still opaque but starting to change)

Do an oil change with a flush regularly and you will be on the road to getting rid of the noise.

By the way - no - there is no code thrown up by this and it is not your timing chain judging by the sound on the video

Thanks for your input, and although i cant say what oil was used, the car had a full service in august, the oil colour looks like new, done less than 1k since service, i can say however, that i was able to contact a previous owner (1 before last) who confirmed to me that when he purchased the car in January 2016, he to had the same  problem & basically rejected the car and got a full refund, so 1) the problem has been there since, at least Jan 16 & 2) the car was sold to me with the fault present, which gives me more ammunition against the dealer.

Thanks for the advice, i guessed there would not be a code :(  , as I've had the car less than 30 days, i'm considering rejecting the car, i have been in contact with the dealer, who, even though is a member of the the motor ombudsman scheme, is not being that helpful. Basically, is the timing chain likely to snap if driven? also, how has anyone here with the same problem had it diagnosed, i assume it has not been stripped down to diagnose?

Thanks in advance. :)

I've recently purchased (dealer) a 2008 IS250 SE MM, I've only had it 3 weeks, it has F/S/H, all but two done at Lexus, after hearing the dreaded rattle on start up, which happens intermittently, i researched this and found that this is a relatively common problem so it seems. I've read several threads on this subject, but there is a few questions i hope can be answered here.

Has anyone had a fault code for this (when plugged in), or is it just, hear the noise and diagnose it? Also how serious is this long term, i know its a big job to replace the cam gears 12/13 hrs labor + parts, which i believe are not cheap, is anyone just living with the problem, or is it a job that needs doing once the rattle starts? 

https://www.youtube.com/watch?v=-CdvBMdG2wc