It must be tricky cos I can't even see it !!!
When I bought my RAV a few months ago, the idle valve was ceased up solid. I managed to free it up and it worked OK for a while. But every 2 to 3 weeks it would jam again. Last time was 2 weeks ago. It jammed and the engine was sitting on 2000rpm! It took 2 days to free it up and get the engine to start.
I hunted round the wreckers and finally found a replacement throttle body complete for $125...not bad since Toyota want $860 just for the idle valve!
Anyway, during my very many throttle body off - throttle body on - body off - body on... for two days, I noticed a slight thin film of oil build up inside the intake manifold. It then dawned on me that I have not checked the air intake of the idle valve...cos I still have that oil loss prob!
I had put the oil loss down to ring end gaps being to close together. But with this latest failure of the idle valve and oil appearing inside the manifold for the first time...my thoughts are that maybe the other end of the idle intake hose needs attention. It may not be a problem, but since I have put on a replacement throttle body, I feel I should do a complete check of the whole system...Something made the other idle valve fail and I would just like to find that something.
BTW. After putting on the replacement throttle body, I went to Toyota and parted with some warm friendly cash (only $40) and had the computer downloaded...The only error shown was the idle valve...That is good news!!
Thanks again for your help...I now at least know what to look for at the other end