Is it possible to see sludge without removing the covers?

[ozone]

Pretty much what the topic says. I don't think most people will let you pull the valve covers off their cars before you take a test drive or something.

[GreeKAvaLoN]

one way i heard/was told was if its really bad you can check the dipstick and see if there is extra residue thats on it after it was wiped. My autos teacher told me about that (lexus/toyota tech =] lucky me) luckily my 1mz didnt show any signs =] now to pull the valve cover soon and see the disaster..

[solara90]

im not sure if this is true but i heard you can look on the under side of your oil filler cap?

[noodlerooney]

You can usually look under the oil filler cap into the valve cover to see BUT don't forget, for the 1MZ-FE, there is a black, sponge-like baffle under the oil filler cap. Do not mistake this for sludge.