28,000 Mile Oil Change...

quick question what brand of oil filter were you using?

 

is that really pitting on the mounting flange? or is it just discolouration? from the pix it looks pitted. Most I have ever seen are smooth. Even in fish. The most corrosive environment for any piece of equipement.

 

the oem Denso//Toyota filter has an O-ring and the can tightens to the flange. I wonder, like you, if someone contaminated the gasket on one and that's the cause of the corrosion. Like I said hundreds of forklifts use in fish processing plants and I haven't seen that yet. Seen holes corroded in the oil tanks but that's only 1/4" thick. Holes corroded in the backing plates on the brakes 1/8" but not the block where the oil filter attaches. Seen the water pump fall off because the nuts holding it on corroded off, and the pressure in the system forced the water pump off the block. Minor stuff like that.

 

Squid,
You been drinkin' and oil (pronounced eurl) changin' again?

Themz some blurry oil pictures.

 

My flange has a little discoloration outside of where the O-ring
seats, but no actual pitting that I can see or feel. [22k-ish miles]
The bigger mystery was the white powdery stuff I could rub off
over the entire exterior of the engine block and transaxle case,
but I assume that's fairly normal aluminum oxidation..
.
_H*

 

As far as the condition of the oil, I think you’ve read my used oil analysis reports. With Mobil 1, 5,000 mile oil changes are way too often. I’m going to slowly increase my oil change interval in 1,500 mile increments – with sampling – to not have to worry about such frequent and wasteful changes.

Operation on salted winter roads are common here too, especially this winter with the frequent freezing rain we’ve had. I haven’t noticed any discoloration or pitting, at least nothing I wouldn’t expect. On my 1984 Ford F-150, I put an Edelbrock aluminum intake on the 302 in 1985, and after 20 years it still looks fairly decent.

Does the car have a service history, or is there a question mark when you bought it? You never know what “maintenance†means to some folks: not pushing it off a cliff might count as “good care.â€

Another possibility: you say you purchased the car with 12K on it. If somebody cleaned the engine bay in typical used car dealer fashion, that may explain the etching. A lot of those degreasers are *very* caustic or acidic and should *not* be used on aluminum, unless you thoroughly rinse afterwards.

In particular, hydrofluoric acid and phosphoric acid will etch off the surface layer of oxidation that aluminum forms, making the surface appear “shiny.†Thorough rinsing with plenty of water, especially DI water, will leave the aluminum looking very nice. After a month or so, the aluminum will naturally oxidize.

Perhaps the top of the oil filter can rolled edge (When mounted you've probably noticed it points almost perfectly up) trapped some of the degreaser, which then had plenty of time to etch the machined aluminum flange. Especially if the car was driven and that acid got nice and warm.

Most oil filters have an obvious rolled lip or edge on the can to allow the collection of fluid, if the oil filter is mounted so the head is pointing up. My 2000 GMC Sierra was the same, though the entire flange area was well protected from runoff from above.

 

you guys know about the airfilter behind the glove box don't you?
Might as well change that one too, or at the least look at it.

 

Now you couldn't possibly be referring to a cheap misanthrope like me?



Actually, it works very good, and is well worth 5 minutes of your time trimming the filter to fit. I get the 14x25 Supreme furnace air filter from Canadian Tire, which is rated MERV 12. It also has a charcoal layer to trap odors.

When I had the house in the Burbs, I also used to cut that filter to fit the outside air intake on my HRV. My indoor air was much cleaner as a result.

 

That's odd.

My 1984 Ford F-150 ran on Mobil Delvac 1 5W-40 the first 10 years of its life. I usually did 10,000-18,000 mile oil change intervals, and only once was the oil actually black when I changed it. Usually a very dark brown.

The oil should have been black, though. I had a Holley 390 4-barrel on that truck until 1991, and Holley carbs almost always run *way* too rich. The Edelbrock 4 barrel I used to replace the Holley has metering rods on the primary, and an air flow valve on the secondary.

I can only theorize Mobil Delvac 1 5W-40 - which is intended for use in large diesel motors and has highly overbased TBN levels - has a very strong detergent/dispersant package. I took the intake manifold off in 1997 and it was spotless underneath, so was the gallery.

 

I would also consider the possibility of a poorly cast or machined block. You won't be able to prove it, though, without a photo of the flange much earlier in its life.

I don't know what the solution is... remachining might remove too much material, and you might then have to modify the central threaded shaft. I would have the dealer look at it, and measure the depth of the pitting before deciding what to do (or not do).

 

It would have been helpful to remove the nitrile gloves to actually *feel* the machined surface. Chemical etching of a metal will not usually produce rough surface, unless done to the extreme.

Otherwise, if the flange surface is truly rough/pitted, it's only a matter of time before it will tear the oil filter o-ring upon installation and cause a slow leak.