Found a reason my Kluger/Highlander is burning oil

Jun 3, 2016
South OZ
Had a check engine light the other day and felt like the car was running on 5cyl (3MZFE). It has always used a bit of oil and I suspected valve stem seals or rings as there would occasionally be a puff of smoke after a long period of sitting or after a highway drive.

Cylinder 4 had a large amount of oil in the spark plug hole and over the coil. The spark plug itself was even more covered on the threads than the pictures show. Replaced plugs on the front bank and the engine is running smooth again.

Can this be caused by valve stem seals or rings? Or is it most likely a bad VCG job done by a mechanic many years ago? (records show VCG done about 80,000kms ago). It's burnt/used oil since I bought it 70,000kms ago. It does drip oil too, making me think the VCG is definitely due for replacement.


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Spark plug tube seals may not have been replaced with the valve cover gaskets, which are usually done together. When I sold my 2003 Highlander, also a 3MZ-FE, it had 265,000 kms with the original VCG's, plugs and coils; It was very reliable.

FYI, this will not help with the oil burning you're detecting at start up.
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Yes that's what I'm thinking too. Or they used poor quality seals. I'd also bet that it wasn't torqued to spec either, since it wasn't done by a Toyota dealership (which usually increases the chance of that happening IMO).
That spark plug gap looks huge so I urge you to replace the rear bank plugs also... after acquiring the appropriate gaskets :D