28,000 Mile Oil Change...

[Mystery Squid]

Originally posted by Frank Hudon@Jan 31 2006, 01:58 AM
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.

[snapback]201067[/snapback]

OR, might it be commonplace on the Prius for whatever reason? I wonder how many Prius owners have paid attention to this sort of thing...

I guess I vote contaminated gasket... but geez, what contaminates aluminum like that? (assuming that is aluminum or some similar alloy)...

[hobbit]

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*

[jayman]

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.”

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.

[parrot_lady]

Originally posted by efusco@Jan 31 2006, 10:11 AM
If you're a K&N fan you can us a K&N air filter on the '04+ Prius too.  I just installed mine a few days ago.

See: http://www.vfaq.net/mods/AirFilter.html

[snapback]201149[/snapback]

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.

[efusco]

Originally posted by parrot_lady@Jan 31 2006, 10:38 AM
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.

[snapback]201212[/snapback]

Yup, The OEM replacements are a bit pricy. Others have purchased larger HEPA filters and cut them to size for change outs to save money and probably get better filtration too.

[jayman]

Originally posted by efusco@Jan 31 2006, 11:49 AM
Yup,  The OEM replacements are a bit pricy.  Others have purchased larger HEPA filters and cut them to size for change outs to save money and probably get better filtration too.

[snapback]201221[/snapback]

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.

[Mystery Squid]

Originally posted by jayman@Jan 31 2006, 12:18 PM
As far as the condition of the oil, I think you’ve read my used oil analysis reports.

I remember skimming through it, but it didn't dawn on me until I got some oil on my bright blue nitrile gloves when removing the drain plug. I was like, "Holy crap, this oil is still mostly golden!". It stuck out simply because I'm used to seeing just about solid black oil from either my old Mustang, or bike. Particularly from when I had my 5.0 302 Cobra, boy, that oil was BLACK after 3k!

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.

I believe it... It's awesome you took the time to do this, I fully admit I'm waaaay too lazy to actually get some sort of results from sampling and take the time to fully comprehend them...

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.”

Well, "service history" as far as Toyota is concerned, I don't know. I bought it at a Toyota dealership as "Certified Pre-owned", so it was a reasonable chance to take given the advantages of buying one year used as opposed to new. Regardless, even if they did have a service history, there's obviously no telling what the prior owner/s might have done anyway, but I suppose it would have at least been an indicator... .eh!

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.

You know, I wouldn't be surprised if this was the case, as the engine bay was immaculate, and clearly "dressed", even though I know it went through at least one New England winter...

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.

Yup, I think a good theory if forming here given it's used, and the engine bay clearly cleaned/dressed! Plus, I know it sat on their lot for some amount of time after I bought it, as my Carfax report stated it was sold to the Toyota Dealership sometime in early March of '05, whereas I didn't drive off with it until late May... So it sort of all makes sense: dealer gets car, cleans the engine bay from all angles and lets it sit there for almost three months, and voila....

[jayman]

Originally posted by Mystery Squid@Jan 31 2006, 12:18 PM
It stuck out simply because I'm used to seeing just about solid black oil from either my old Mustang, or bike.  Particularly from when I had my 5.0 302 Cobra, boy, that oil was BLACK after 3k!

[snapback]201243[/snapback]

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.

[KTPhil]

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).

[jayman]

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.