Is Oil responsible for engine colour?

[slybunda]

hello all, so i have been wondering i removed the valve covers of both my engines and the colour of the insides look very different.

is the metal used the reason or is it the type of oil used that makes the insides more yellow?

pics attached:

Yellow engine is a 2zz-ge toyota celica
other engine is 1995 1.6 ford fiesta zetec 16 valve

how do they look?

 

[tojo1968]

How many miles on the engines?
Top one looks like normal, harmless varnish.
Bottom looks like new!

 

[aquariuscsm]

What oils were used in both?

 

[Xrs2zz]

I have the 2zz-ge in my Matrix and it also has that yellowish color. Was fed dino oil until 160k miles and maybe that had something to do with it?

Since switching to syn for the last 27k miles, it has cleaned it up some, but I doubt it will ever go away. A buddy of mine with the 2zz-ge in his Corolla had used syn since new and his didn't have the yellow color at all.

 

[slybunda]

the yellow toyota engine has 84k miles on the clock, its got full toyota service history oil changes were done around 8-9k mile intervals. i suspect the dealers used 5w-30 semi synthetic.
its currently running a m1-209 filter and mobil super 3000 x1-fe oil, first oil change i done by myself on a car!

the fiesta engine in the bottom pic is coming up to 76k miles, its 20 years old but iv had it since 10k miles on the clock and been doing oil changes every 5k miles, some of those 5k intervals take 2 years to do. oil changes were done at quick lube type of places, in uk we have kwik fit and national tyres. its had all sorts of brands thrown at it castrol magnatec, duckhams etc. i specify fully synthetic to the oil change places but i dont think they use fully and suspect they use cheap semi since it comes out of a tap in the wall.

fiesta had valve cover gasket leak so changed the gasket and was surprised to see the colour difference in the engines.

fiesta has had its first oil change done by myself last month. used shell ultra 5w-30af and fram xg3600.

i wont be using the oil change shops again from now on i will do it myself so i know what oil is actually going in it.

 

[Kuato]

Color difference is interesting....perhaps the metallurgy has something to do with it?

 

[Ducked]

Originally Posted By: Kuato
Color difference is interesting....perhaps the metallurgy has something to do with it?


Don't think so.

As above, light varnish/no varnish.

I'd guess a conventional/synthetic oil difference at some point. I suppose antioxidant levels, OCI or detergency differences MIGHT also be a factor, but once its on its quite difficult to get off.

Both look good, the lower one especially so given its age. Have to seek Kwik-Fit bashing support elsewhere.

 

[jdavis]

They both look to be in great condition. The top ones varnish is most likely due to dino/conventional oil but it's not causing much if any actual harm.

If it were mine I'd be switching to Pennzoil Gold or PP/PUP and checking back after a while but in all honesty it doesn't really matter. I'm just a perfectionist that loves to see clean/varnish free engines, kind of like Merk.

 

[KitaCam]

The Kitacam @ 100K miles...

 

[jdavis]

I wonder what it looks like now.. have you been using PP for the last 32k+ miles?

 

[KitaCam]

Yes...PP or PP+ since 100k miles....
Next Jan. I'll be giving the Kitacam its 4-yr replacement of all fluids and maybe then we'll look under the valve cover and see what it looks like....

 

[slybunda]

Im using fully now would that help with the varnish or do i need stronger cleaners?
Or is it a case of taking off the cover again and using a brass brush?

 

[alcyon]

My camshaft removed to change the stem seals, which it thought were leaking (actually wasnt, it was exhaust pipe condensation). anyway here are some pics. Engine has 160,000 km since rebuild in late 2004.





using group 3 synthetics 95% of the time.

 

[jdavis]

Originally Posted By: slybunda
Im using fully now would that help with the varnish or do i need stronger cleaners?
Or is it a case of taking off the cover again and using a brass brush?


Nah, just using full synthetic from now on should gradually help. I prefer PP or PUP for cleaning power.

 

[Merkava_4]

That yellow color is varnish and it can do nasty things like cause your cam phaser solenoids to freeze up and block the oil return holes in your piston ring lands - causing your oil control rings to seize and start massive oil consumption. Long oil drain intervals will cost you a lot more in the long run I guaranty you.

 

[slybunda]

Advice taken. I will stick to fully on short 5k intervals hopefully it cleans up so i can push intervals to 7.5k

 

[slybunda]

actually i made a mistake in the mileage on the celica yellow engine. that picture was taken when i first got the car and changed the lift bolts out. mileage was around 75k. so photos are taken with both cars on similar mileage.

celica since then has had 2 oil changes so will be interesting to see if there is any improvement.

 

[GaleHawkins]

Thanks for the photos. The yellow tint seems to be on the lobes of some of the cams as well. It it is at a wear point in might be at the crank as well.

Having been around engine tear downs for 60 years both these engines look new like compared what I would see in the 50-60's with non detergent oils.

 

[bullwinkle]

Originally Posted By: GaleHawkins
Thanks for the photos. The yellow tint seems to be on the lobes of some of the cams as well. It it is at a wear point in might be at the crank as well.

Having been around engine tear downs for 60 years both these engines look new like compared what I would see in the 50-60's with non detergent oils.

I haven't been around that long, but I've had a few neglected sludge monsters that I WISH had only a little yellow varnish on them. Find a deal on some PU (Pennzoil Ultra), it'll take that off. If they have it in the UK, that is.

 

[slybunda]

Im in the uk i will have a look at that oil. Shell helix ultra is available here but dunno how it is at cleaning