Hello,
I was changing oil yesterday and now I have a question:
Can anyone comment on the purpose of a metal plate inside an oil filler neck?
I have 96 4Runner with 3.4 and you can see this plate if you open oil cap on a valve cover. On my truck this plate looks very bad: it has a layer of burnt oil and looks ugly.
I’ve heard that Camry and Avalon with 3.0 V6 have same plates and they look bad as well, I am not sure about 4 cylinder models. I am changing oil every 3000 miles and that thing still looks horrible.
So I would like to know what a purpose of those plates is and why look that bad? Do they exist only in Toyotas?
Or may be it is only in my truck?
Thanks.

 

Generally, those plates are designed as a baffle to prevent oil from splashing back up the filler neck when the engine is running. The reason they look brown is because there is very little oil flow across them to keep them clean.

 

Thank you TechWrench!