VansAirForceForums  
Home > VansAirForceForums

- POSTING RULES
- Donate yearly (please).
- Advertise in here!

- Today's Posts | Insert Pics


Go Back   VAF Forums > Main > RV Ongoing Maintenance Issues
Register FAQ Members List Calendar Today's Posts

Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 05-18-2014, 01:24 PM
Bavafa Bavafa is offline
 
Join Date: Oct 2007
Location: Sacramento, CA
Posts: 3,344
Default The color of the oil in our engine

I was wondering if the color of the oil in our engine can be used to indicate any thing in our engines?
I have been changing my oil in our cars for the past 30+ years so I am quite used to seeing old oil that comes out of our cars and know that dark oil does not necessarily mean a near kaput engine just as I know that even a 500-1000 mile on an oil would make it go dark to some degree.

On the other hand, In my plane, I often see a rather fresh-looking oil color even after 30 or more hours of flying. So I was wondering would a lack of dark color in oil mean anything bad?
__________________
Mehrdad
N825SM RV7A - IO360M1B - SOLD
N825MS RV14A - IO390 - Flying
Dues paid
Reply With Quote
  #2  
Old 05-18-2014, 01:49 PM
Sig600 Sig600 is offline
 
Join Date: Nov 2005
Location: KRTS
Posts: 1,798
Default

I don't remember where I read it, but yes engine color can be used to determine oil abuse.

I still wouldn't change the interval though. Oil change is a good opportunity to do a firewall forward conditional. Things like fuel and oil leaks need to be caught early.

I also do an oil analysis every oil change.

http://www.blackstone-labs.com/free-test-kits.php

$25, they send you the kit for free. Just fill out the slip, mail back the bottle. They'll not only email you the results but they'll keep track of them and give you trend analysis on what could be what. It's the only true way to find out what is going on in there.
__________________
Next?, TBD
IAR-823, SOLD
RV-8, SOLD
RV-7, SOLD
Reply With Quote
  #3  
Old 05-18-2014, 01:50 PM
mike newall's Avatar
mike newall mike newall is offline
 
Join Date: Jan 2005
Location: Yorkshire, England
Posts: 2,048
Default

I used to notice that Lycoming went dark gray and Continental went green - don't ask me why.......
__________________
"I add a little excitement, a little spice to your lives, and all you do is complain!" - Q

Donated in 2020
Reply With Quote
  #4  
Old 05-18-2014, 07:16 PM
BillL BillL is offline
 
Join Date: Sep 2007
Location: Central IL
Posts: 5,514
Default

There are many parameters of oil degradation, one of these is oxidation and is measured in the lab. Time at temperature will darken the oil due to oxidation. Lack of darkening means that it runs cooler in your engine. That is good.

Do you run 100LL or mogas? I would expect mogas to leave the oil more honey colored not the typical progression of opaque color.

Oils see different temperatures in different engine. My Saturn turned the oil black in 3000 miles (hot), I switched to synthetic Mobil1 and it still darkened significantly in 3000. My neighbors Honda Civic oil at 3000 miles still looked new. His Civic engine lasted significantly longer.
__________________
Bill

RV-7
Lord Kelvin:
“I often say that when you can measure what you are speaking about,
and express it in numbers, you know something about it; but when you
cannot measure it, when you cannot express it in numbers, your knowledge
is of a meager and unsatisfactory kind.”
Reply With Quote
Reply



Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -6. The time now is 06:03 PM.


The VAFForums come to you courtesy Delta Romeo, LLC. By viewing and participating in them you agree to build your plane using standardized methods and practices and to fly it safely and in accordance with the laws governing the country you are located in.