wrong valve timing from the factory?

[Clevy]

I can't believed no one asked yet so I am.
What oil,grade and interval? How long have you had the car and what kind is shape was the engine in when you first started.

 

[sciphi]

Originally Posted By: LeakySeals
You have a vvt-i, should cause noticeable problems.


I've heard urban legends that VVT can mask timing problems to an extent by advancing/retarding the timing itself. Not sure if those are legends or if there's a grain of truth to that...

 

[friendly_jacek]

Since you asked, I changed oil every 6 months, 4,000-5,000 miles. Toyota bulk oil under warranty till about 50,000 miles and later VWB or PYB. Oil consumption started somewhere near 65,000 miles and I did a few MMO and later Kreen piston soaks/treatments. I would credit MMO/Kreen for cleaning. The OCI before the last was Maxlife conventional and there was almost no oil consumption in over 3,000 miles. The last OCI was QS synthetic (6,000 miles) and consumption came back in the first 2,000 miles. Now, I just changed oil and used Maxlife synthetic.

I checked valve clearance now since the majority of those miles were city driving at low speeds. I calculated that this mileage would be equivalent to over 200,000 miles of hwy driving engine hrs wise. Indeed, iridium spark plugs had major wear at 75,000 miles.