Notices
Series I Trouble Shooting This is the place to learn more about or discuss any issues you're having with your RX-8

Compresion drop in the last year

Thread Tools
 
Search this Thread
 
Rate Thread
 
Old 06-10-2010, 12:20 PM
  #26  
Registered Zoom Zoomer
iTrader: (2)
 
Huey52's Avatar
 
Join Date: Apr 2006
Location: New England
Posts: 4,089
Likes: 0
Received 6 Likes on 6 Posts
I didn't say the 'w' stood for Winter (although it did per the SAE's initial classification).

The first number is the dynamic viscosity, how the oil behaves at a very low temperature. Especially interesting is to what temperature the oil is still flowing to the oil pump by itself. E.g. “5W” means that the oil still flows at minus thirty degrees Celsius.

I too run 5w30 (Castrol GTX), year 'round.

edit: that's it, BHR gets deleted from my "good guys" list! (j/k)

Originally Posted by Flashwing
Oh Denny you were so nearly there! You are right on the money that your engine temperature and overall internal environment doesn't change regardless of what the ambient temperature is. Therefore, because oil is thickest when the motor is cold you want a viscosity at startup that is as close as possible to the viscosity of the oil when the motor is up to temperature. 20w/50 is like pushing honey through your motor.

Castrol GTX 20w/50 cSt @ 40 degrees C: 143.1, @ 100 C: 18 (Spread is 125 cSt)
Eneos 5w-40 (which I run now): cSt @ 40 degrees: 82.5; @ 100 degrees: 14.0 (spread is 69 cSt)




No, the "W" is an indication that the oil is a multi-viscosity oil. There is no winter rating for any oil.



Marc, if you need more information let me know and I'll take care of you.

Last edited by Huey52; 06-10-2010 at 12:59 PM.
Old 06-10-2010, 12:44 PM
  #27  
My 8 looks like a Smurf
Thread Starter
iTrader: (4)
 
TheWulf's Avatar
 
Join Date: Sep 2007
Location: Ottawa, ON, Canada
Posts: 1,742
Likes: 0
Received 0 Likes on 0 Posts
Todd are you talking about these: (thanks nycgps for the img and the purty writing)

I'll give it the week and do a compression test next weekend. I'm also gonna have to wait until then to change the plugs as I'm waiting on my BHR order to ship!
Old 06-10-2010, 12:56 PM
  #28  
B.I.G
iTrader: (4)
 
05rx8mazda's Avatar
 
Join Date: Aug 2007
Location: AT---EIL
Posts: 1,401
Likes: 0
Received 0 Likes on 0 Posts
10w -40 does it for me I am seeing 18-19 for vacuum I was gonna try 0w-50 rp
Old 06-11-2010, 07:45 AM
  #29  
My 8 looks like a Smurf
Thread Starter
iTrader: (4)
 
TheWulf's Avatar
 
Join Date: Sep 2007
Location: Ottawa, ON, Canada
Posts: 1,742
Likes: 0
Received 0 Likes on 0 Posts
So I went and bought the zoom power cleaner today... Canada gets "hosed" again (pun intended): we don't get that 2'-3' long hose that the US guys get with the aerosol can. We get a tiny stubby like the one that comes with a can of WD-40.

You'd think that this would be something easy to track down, but apparently no one sells aerosol hoses...

I am thinking I MIGHT be able to get to those vacuum nipples with the shorter hose if I go from the bottom but I am on the lookout for a longer hose. If anyone has any pointers on where to source that -- especially locally -- that would be awesome.
Old 06-14-2010, 08:23 AM
  #30  
My 8 looks like a Smurf
Thread Starter
iTrader: (4)
 
TheWulf's Avatar
 
Join Date: Sep 2007
Location: Ottawa, ON, Canada
Posts: 1,742
Likes: 0
Received 0 Likes on 0 Posts
Ok so Seafoam done :D

http://www.youtube.com/watch?v=aLDgU...layer_embedded

I did notice however that after that I have a vacuum leak somewhere near the UIM. It's only noticeable after the engine is hot but it's pretty loud. This is gonna be fun to track down...
Old 06-14-2010, 08:24 AM
  #31  
The Angry Wheelchair
iTrader: (14)
 
Vlaze's Avatar
 
Join Date: May 2009
Location: In da woodz, lurking after you
Posts: 1,865
Received 1 Like on 1 Post
Dumb question, but did you make sure to put the vacuum caps back over the nipples?
Old 06-14-2010, 08:39 AM
  #32  
My 8 looks like a Smurf
Thread Starter
iTrader: (4)
 
TheWulf's Avatar
 
Join Date: Sep 2007
Location: Ottawa, ON, Canada
Posts: 1,742
Likes: 0
Received 0 Likes on 0 Posts
lol yes, that is the first thing I checked.

Actually with the 06+, there are vacuum tubes attached to the nipple with a T connection running to the oil case. I made sure they were re-attached.

The leak actually seems to be coming from the middle of the top of the UIM somewhere...
Old 06-14-2010, 09:26 AM
  #33  
Registered
iTrader: (3)
 
olddragger's Avatar
 
Join Date: Apr 2004
Location: macon, georgia
Posts: 10,828
Likes: 0
Received 38 Likes on 27 Posts
probably from the vacuum box area where the purge etc all go to?

an healthy engine will have 18-19 of vacuum. 17 is ok. at 16 its time to start thinking. it will run ok but there is a good deal of wear.

As for as oil goes-- do a good search in this forum. Mazmart/BHR/RR and a bunch of others have contributed to the discussion. Pressure/lubrication and viscosity's have all been talked about. Look at some used oil analysis's and see which oils are maintaining their viscosity.
hope the carbon cleaner works for ya!
rotor on dudes
Old 06-14-2010, 09:37 AM
  #34  
Registered
iTrader: (2)
 
RIWWP's Avatar
 
Join Date: Oct 2007
Location: Pacific Northwest
Posts: 16,684
Likes: 0
Received 240 Likes on 110 Posts
OD,

Is measuring the vacuum from those ports a viable alternative to a compression tester? I know that they are related, but not quite the same thing, but it seems that a constant vacuum gauge there might be a reasonable way of knowing when it's time to take it in for an official compression test, without the more expensive digital compression tester.


This accurate?
Old 06-14-2010, 09:59 AM
  #35  
My 8 looks like a Smurf
Thread Starter
iTrader: (4)
 
TheWulf's Avatar
 
Join Date: Sep 2007
Location: Ottawa, ON, Canada
Posts: 1,742
Likes: 0
Received 0 Likes on 0 Posts
Originally Posted by olddragger
probably from the vacuum box area where the purge etc all go to?
Do you have a visual for the "experience impaired"?
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Duren1
Mountain For Sale/Wanted
3
01-11-2017 09:07 AM
bullbuchanan
RX-8 Discussion
26
03-24-2016 12:37 PM
TeslaMSI
New Member Forum
11
12-10-2015 01:10 AM
Nisaja
RX-8 Discussion
51
09-01-2015 04:29 AM



You have already rated this thread Rating: Thread Rating: 0 votes,  average.

Quick Reply: Compresion drop in the last year



All times are GMT -5. The time now is 09:33 AM.