Different colour oil under cam covers? *pics*

[danny20]

I bought a 1UZ as part of a package a while ago and when i got it the owner said the engine was "breathing" which didn't really bother me as they're cheap enough to replace anyway. Only wanted the package for the other parts which came with it. However just out of interest i took the cam covers off to see what it looked like under there. As you can see, under the left hand cam cover is a lot darker. I just put that down to the rings being a problem on that side. However i just took the covers off my new motor also and it seems to have exactly the same thing?

Just wondering if anyone can explain why this would possibly be happening? And if anyone else has noticed that the oil looks burnt in the left hand side compared to the new looking oil in the right? Something to do with the PCV maybe?

Old motor Right hand side

Old motor left hand side

New motor left hand side

 

[cpcc]

Mines looked the same. Still working smooth 1 year later. I did take down the oil pan and found 2 handfulls of sludge in it.
Couple of engine flushes later, the car was purring.

 

[sonyman]

I'm pretty sure that's varnish.

 

[danny20]

I'm pretty sure that's varnish.

What's varnish?

 

[FrankMS]

bake oil

FranK

 

[gloverman]

most look like that - It is oil staining in different places depending on where the oil splashes - cheers

 

[striker]

think it's PVC system related though, mine also has this to a very small amount, the clean side has the PCV hose attached, the other cam cover (dark one) breathes through the smaller ID one way valve.

Been thinking of breathing both cam covers to a closed tank that is put under vacuum at the supercharger entry, with baffles in it the tank should prevent oil entering the chargers. tank drains back to the sump, so PCV function is retained. I see that way done on a lot of hillclimb cars either vacuumed or just filtered to ambient air.

Grtz Thomas

 

[ozvenom]

Breather

Hi guys you are on the right track it is caused by the pcv system the dark colouring is all the junk that is blown into the crank case past the rings and also and oil which is airated by the crank spinning around. this also has a another negative side effect which is it wears the shim buckets underneath where it sits on the valve stem which is why why the left bank always needs more adjusting.
To reduce this change your oil regularly use synthetic oil it has less crap in it and also handles heat better. the japanese are not too fond of changing oil this is why its so bad . still the best engine going.:yeah: