1MZ-FE Valve Cover Gasket Change - 471,000 Miles

[kschachn]

The valve cover gaskets have been leaking, I looked back and the last time I changed them was 172,000 miles and 10 years ago. On this engine that is too long as they get hard and no longer seal.

Here is what it looked like under the covers. The rear cover was replaced at the last gasket change with the new and improved rear cover and PCV valve. The front cover is original to the engine.

Oil changes average around 6-7K and I've always used synthetic but not a boutique. Much different engine than the 1NZ-FE in my old ECHO.

Front head:

Rear head:

Front cover:

Rear cover:

 

[JavierH19]

Not bad at all for the mileage. Looks good to me.

 

[Urshurak776]

Looks amazing to me for that kind of miles. Well done!

 

[carviewsonic]

471000 miles, that's impressive mileage. Looks very good. Toyota is a great brand.

 

[paulri]

Looks clean for 471K, that's for sure.

I guess you are going to keep it for a while yet? I recall reading your account of a timing belt change (quite a few years ago IIRC) and you said that that would be the last one. Our 3MZ is only at 195K; I'll be happy enough to get 300K out of it. 471 gets a gold medal.

 

[Patrick0525]

Any oil consumption in an oil change interval?

 

[wwillson]

Oil changes average around 6-7K and I've always used synthetic but not a boutique.

There is quite a bit of varnish on the inside of the valve cover and some on the stationary parts on the head. Had you used a boutique oil like HPL that has a documented ability to keep internals clean, do you think we would see this varnish even at 471k miles?

 

[kschachn]

There is quite a bit of varnish on the inside of the valve cover and some on the stationary parts on the head. Had you used a boutique oil like HPL that has a documented ability to keep internals clean, do you think we would see this varnish even at 471k miles?

Probably. But then again it is nearing the EOL for other reasons so likely not worth the money.

 

[kschachn]

Any oil consumption in an oil change interval?

It uses about a quart in between which isn't a whole lot more than it has used for a long time.

 

[kschachn]

I guess you are going to keep it for a while yet? I recall reading your account of a timing belt change (quite a few years ago IIRC) and you said that that would be the last one. Our 3MZ is only at 195K; I'll be happy enough to get 300K out of it. 471 gets a gold medal.

It's pretty much a dog hauler now or I use it to take stuff to the landfill or pull a small trailer for mulch.

 

[slacktide_bitog]

Looks good

I know the 1MZ is very difficult almost impossible to work on, so kudos for actually tackling the job again

 

[Patrick0525]

Probably. But then again it is nearing the EOL for other reasons so likely not worth the money.

It has b

There is quite a bit of varnish on the inside of the valve cover and some on the stationary parts on the head. Had you used a boutique oil like HPL that has a documented ability to keep internals clean, do you think we would see this varnish even at 471k miles?i

It has been reported that this engine statistically suffers the proverbial engine sludge. OP has avoided it so that in itself is remarkable and testament to synthetic ocs.

 

[SatinSilver]

Any exterior pictures of it after all those miles?

 

[Nuclear_42]

Perfect candidate to run some Valvoline Restore & Protect for 20k check the valves again.

 

[Kira]

An academic question:
If one wanted to, what could you soak those valve covers in to dissolve the varnish?
Gasoline? Paint thinner? Denatured alcohol?

 

[kschachn]

An academic question:
If one wanted to, what could you soak those valve covers in to dissolve the varnish?
Gasoline? Paint thinner? Denatured alcohol?

Yes the varnish is removable. The harder black crust wants to stay attached.

 

[KrisZ]

Wow! Almost 500k miles done over 25 years, that’s super impressive.