Using 10w-40 due to low oil pressure? - JeepForum.com
Reply
 
LinkBack Thread Tools
post #1 of 19 Old 12-17-2012, 09:46 AM Thread Starter
streetzj
Registered User
1997 ZJ 
 
Join Date: Dec 2009
Location: minnesota
Posts: 380
Using 10w-40 due to low oil pressure?

I'm using 10w-40 to increase my low oil pressure, which is caused by bad bearings. It increased the pressure from 5 psi to 9 psi over 5w-30 when I changed the oil this summer. But now it's winter here in Minnesota -- which weight should I use?

It seems to me that it's a matter of the least worst -- when the engine is warmed up after about 20 minutes, the 5w-30 will cause the pressure to go back down to 5 psi, which is bad. But when I start it in the cold, the 10w-40 is too thick to reach the top right away, which is bad.

Either way, the oil won't reach the top at some point. And important note -- the pressure is only low at idle and is fine at cruising speed, and increases to normal from low pressure when I accelerate.

streetzj is offline  
Sponsored Links
Advertisement
 
post #2 of 19 Old 12-17-2012, 09:51 AM
JohnnyZJ
Registered User
2007 JK Wrangler 
 
Join Date: Oct 2008
Location: Calgary
Posts: 2,571
gear oil will bring it up a bit.

keep the jeep plugged in that will help

07' JKUR rollin on 35s
JohnnyZJ is offline  
post #3 of 19 Old 12-17-2012, 10:00 AM
Candymancan
Registered User
1998 ZJ 
 
Join Date: Aug 2010
Location: Virginia
Posts: 5,067
Why are you even using 5-30 anyway they are ment to use 10-30.. ill never understand why ppl do that..

2013 6.2 V8 Camaro SS 30k
98 5.9 V8 ZJ 180k
98 4.0 I6 ZJ 240k
90 5.9 SJ Grand Wagoneer 110k
Candymancan is offline  
post #4 of 19 Old 12-17-2012, 10:03 AM Thread Starter
streetzj
Registered User
1997 ZJ 
 
Join Date: Dec 2009
Location: minnesota
Posts: 380
I guess I've always been told to use 5w-30?

But I've also been warned against using 10w-40 in Minnesota winters...
streetzj is offline  
post #5 of 19 Old 12-17-2012, 10:18 AM
PolkaPower
Registered User
1998 ZJ 
 
Join Date: Aug 2011
Location: The Abyss
Posts: 19,250
Quote:
Originally Posted by streetzj View Post
I guess I've always been told to use 5w-30?

But I've also been warned against using 10w-40 in Minnesota winters...
Why don't you use 5W-40?
PolkaPower is offline  
post #6 of 19 Old 12-17-2012, 10:19 AM
PolkaPower
Registered User
1998 ZJ 
 
Join Date: Aug 2011
Location: The Abyss
Posts: 19,250
Quote:
Originally Posted by Candymancan View Post
Why are you even using 5-30 anyway they are ment to use 10-30.. ill never understand why ppl do that..
It's the same weight warmed up. Just gets up into the motor faster at start up. It seems to have rid me of my cold morning knock I was having.
PolkaPower is offline  
post #7 of 19 Old 12-17-2012, 10:20 AM
Uniblurb
Web Wheeler
 
Uniblurb's Avatar
1996 ZJ 
 
Join Date: Jan 2012
Location: Central
Posts: 6,725
I wouldn't even use 10W40 in he summer and follow the spec to use 10W30 year round in all our Jeeps. Always have and always will. And yeah, my oil pressure is just a little low at idle on my 96 4.0 but don't believe it's doing any damage and picks right up when accelerating.

For MN winters believe I'd be using a block/engine heater plugged in overnight if possible.
Uniblurb is online now  
post #8 of 19 Old 12-17-2012, 10:54 AM
JohnnyZJ
Registered User
2007 JK Wrangler 
 
Join Date: Oct 2008
Location: Calgary
Posts: 2,571
Quote:
Originally Posted by Candymancan View Post
Why are you even using 5-30 anyway they are ment to use 10-30.. ill never understand why ppl do that..
anything thicker in the really cold weather and the jeep will likely not start. you woulnd't see anything like that in Virginia. (unless you guys get -40 degrees there?)

i run 5w30 in the winters. much smoother in most situations. 10/30 in the summer.

keep in mind, the heavier oil will help with pressure but on cold mornings its as thick as molasses. i'd keep it plugged in if you do that for sure

07' JKUR rollin on 35s
JohnnyZJ is offline  
post #9 of 19 Old 12-17-2012, 11:08 AM Thread Starter
streetzj
Registered User
1997 ZJ 
 
Join Date: Dec 2009
Location: minnesota
Posts: 380
Ok, I think I will go with a 5w for the winters, because it does get well below zero here in Minneapolis. Outstate and northern Minnesota see -40 like your part of Virginia.

I kinda like the earlier idea of 5w-40, but some of you guys seem against a 40w, even with my bad bearings?

And what again does anyone think is the cause of that knocking sound?
streetzj is offline  
post #10 of 19 Old 12-17-2012, 05:19 PM
zander21510
Registered User
1995 ZJ 
 
Join Date: Jun 2011
Location: Dallas
Posts: 2,139
I started using 5w40 Rotella T6 synthetic just to see if it was any good. It got rid of some noises, seems like good stuff. Oil pressure is pretty stable except at warm-up where it can get somewhat low idling after a stop.
zander21510 is offline  
post #11 of 19 Old 12-17-2012, 05:34 PM Thread Starter
streetzj
Registered User
1997 ZJ 
 
Join Date: Dec 2009
Location: minnesota
Posts: 380
I'm also thinking of trying that actually. Thanks!
streetzj is offline  
post #12 of 19 Old 12-18-2012, 04:36 AM
Foundrydude
Registered User
1995 ZJ 
 
Join Date: Jan 2011
Location: Flatsville
Posts: 2,690
Be gentle to it when it starts. A bit of knocking on cold start is tolerable. A bit of knocking on a warmed up engine is certain death.

Basically run whatever oil you need to keep it from knocking when warm, and live with whatever it does cold. I wouldn't hesitate to use 20-50 if that's what it took to prevent knock while driving
Foundrydude is offline  
post #13 of 19 Old 12-18-2012, 04:47 AM Thread Starter
streetzj
Registered User
1997 ZJ 
 
Join Date: Dec 2009
Location: minnesota
Posts: 380
Thanks.

I now think the knocking is a lifter, so that's my next thread!
streetzj is offline  
post #14 of 19 Old 12-18-2012, 04:59 AM
LouC
Registered User
2007 WK 
 
Join Date: Feb 2008
Location: NY
Posts: 1,735
I've been using 10w/30 Valvoline Maxlife and the oil pressure on my 98 ZJ 4.0 is 30 psi hot at idle, 40-50 driving..
LouC is offline  
post #15 of 19 Old 12-18-2012, 03:37 PM
Foundrydude
Registered User
1995 ZJ 
 
Join Date: Jan 2011
Location: Flatsville
Posts: 2,690
Quote:
Originally Posted by streetzj View Post
Thanks.

I now think the knocking is a lifter, so that's my next thread!
That's called ticking
Foundrydude is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the JeepForum.com forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid e-mail address for yourself.



Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



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

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome