Oil gunk under the fill cap revisited - got the Blackstone results back.

Some of you may remember the pictures I posted of my oil cap earlier this year in this thread...

http://www.tacomaworld.com/forum/2n...milky-condensation-oil-cap-filler-neck-3.html

If you missed it, here is what my oil cap and filler tube looked like in February when I did my first oil change.





I was scared shitless thinking I had somehow had coolant in my oil. Further research found that this is not uncommon despite going against conventional wisdom. I have checked my oil cap and filler neck during every other fill up since then, and as the weather got warmer, the gunk got less and less prevelant to the point where for the last few months there have been ablsolutely no traces of gunk. To be sure there was nothing amiss, I sent a sample to Blackstone to get analyzed. Got the results back a couple days ago. The narrative states there are trace amounts of sodium but they believe it's due to oil from previous changes. That makes sense because the service records indicate that the previous oil changes were done with non-synthetic Mobil 1.

Here's the Blackstone report...

 

Mine is the same. I freaked out at first too. It's due to not getting the engine to operating temps before shutting off. In the summer time it doesn't take as long to get to temp, hence less residue.

 

That's nasty. Good to hear the taco will still be fine for 300,000 miles.

OP, that "street racing gone bad" post is quality. Would be nice if kids around here read that.

 

I notice you live in a part of the USA that gets snow and you said as it got warmer the gunk went away. Was the gunk prevalent when you had snow on the ground? You guys salt the roads there right?

 

Dream on my friend, dream on, they use to, not ours.
take care
vbibi

 

Hahaha thats funny, I like that really teaches a lesson

 

We get snow maybe a couple times a year but haven't had it since I've owned my truck. It normally doesn't stick around more than a couple days. The gunk is more prevalent during cold temperatures and with short trips because the engine doesn't get warm enough to evaporate off mositure in the air. So as spring and eventually summer came around, the moisture evaporates off even with the short trips because of the higher ambient temps. We don't salt the roads in my neck of the woods. They use a combination of sand and a chemical de-icer.



I'm glad you guys like the street racing thread. It's one of the more popular ones on s2ki.

 

Yeah, that's just water condensate due to the oil not reaching sufficiently high operating temperature to "cook" combustion water out of the system via the crankcase ventilator.

That's why I installed a remote, bypass oil filter on my engine. The bypass filter actually absorbs the water that forms your orange grunge.

If you think your filler cap looks bad, visit your local airport and check out the filler caps on the "old tech" engines on light aircraft that only have "road tube"-style crankcase ventilators!

My machine, a Cessna, drips that goo from the vent tube whenever temperatures are even CLOSE to cool!

 

I have noticed this in my 2006 truck since I bought it new in Mar 2007.
It has run Mobil 1 since its first oil change.
My older non-tacomas did it too and my tundras but not to the extent of the tacoma seasonally.
The Tacoma seems to collect more stuff like your first picture & the color was different which at first concerned me some.
Last weeks oil change no trace was in the cap or filler neck but the leaves are changing as I type.....

 

That often happened to a Civic I owned a long time ago. Scared the he'll out of me too when I first saw it!!!!

 

I had that same issue as well. I had never in all my years living in New England and doing all of my own oil changes seen so much froth in my oil. As far as I can tell this is a Toyota specific anomoly.

When I did my first winter oil change on the Taco, (running AMSOIL) I freaked out. I thought that I has a major coolant leak into the engine. I had it towed to the dealer for an inspection and pressure/leak check.

It turned out to be fine. The dealer called their technical reps at Toyota USA and they said that people w/ short winter commutes may experience "slight" buildup of brown-yellow gunk.
FWIIW, It looked liked an entire can of vaseline made it into my filler neck!
When the weather warmed up the buildup went away. :dunno:

I still don't think that nearly that much water should make it into my oil!

 

I can tell you it is not Toyota specific because I know guys on VW forums were obsessing over the same thing, with pic's very similar to the OP's (of his oil cap) being posted.

The good thing is, a nice long drive at highway speed made it look normal and their UOA's were normal too.

I'm interested in just what you're drive regimen is: how long is your commute, and at what speeds? How often do you get out to freeway speeds, for how long? Something like that...

 

At the time is was 3 miles into work, 3 miles home... 0 traffic lights! The only hangup is getting through the fence. I was doing that 4 days/week one week, 5 days a week the other.

On the weekends I was driving 100 miles up Thursday or Friday night, and 100 miles South Monday mornings.

 

It's water in the oil, some will condense naturally in the crankcase as the vehicle sits, and water is also a by-product of combustion. As long as the pcv system is working, the water will boil out as the engine reaches operating temperature. Most common cause of this buildup is frequent short trips that do not allow the engine to reach operating temperature long enough to boil off the water, especially in winter. If you live 3 miles from work, for example, the vehicle will need to be driven farther at regular intervals to help avoid this. Or the crankcase ventilation system (pcv) needs some attention...