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View Full Version : 10w40 oil for '90 KA24e



**DONOTDELETE**
11-06-2001, 08:40 AM
i am currently using mobil 1 5/10w30 oil, 10w30 for summer, just switched to 5w30 for the winter, but i'm thinking of switching to 10w40. i dont think any oil is being burned but there are a few very minor oil leaks, it seeps from the from seal and around the valve cover but what's actually bothering me is that the oil pressure is barely in spec. it's 11 at idle and, lately, just under 60 at 3k rpm, probably from the 5w30 oil change. (i think i need to flush the system too after my oil pan job, it's probably crapped up with sealant chunks). i've got a 3 month old oil pump and the oil pickup and pan were changed.

would using 10w40 raise the oil pressure? do they even make full synthetic mobil 1 10w40? would the engine handle it no problem and benefit from it?

please let me know, thanks.

**DONOTDELETE**
11-06-2001, 09:35 AM
They make a 15W-40 Mobil1, but probably not a good idea to use in MA winter.

It is not unusual for synthetics to have somewhat lower oil pressure than crude, since they have much better flow characteristics - better flow = better lubrication = lower pressure.

FWIW, I have read that it is usually not recommended to use a synthetic with a wide viscosity range (more than 20 points), since these might need viscosity enhancers which are not needed by synthetics with a narrower spread (An article I read said that Mobil1 does not use any viscosity enhancers in its 5W-30 or 15W-40, while Amsoil uses some in 5W-30 and 10W-40). These enhancers get used up resulting in loss of either low-temp flowability or high-end shear stability - synnthetics without these enhancers have much better long-term viscosity stability. The exception would be if it is cold enough to need 5W, in which case 5W-30 might be needed, but a 10W synthetic will actually have better extreme low-temp flowability than a 5W crude - the winter rating is taken at 0 degrees Fahrenheit, but good synthetics can flow down to 50-60 below 0, with NO pour point depressants which are needed in crude (and which get used up).

I got the info quoted above from the following link:

http://www.vtr.org/maintain/oil-overview.html

[ 11-06-2001: Message edited by: Scott T ]

**DONOTDELETE**
11-07-2001, 06:59 AM
i think i might actually switch back to 10w30 for the winter. what about 0w40?

one mroe question, is the oil pressure sensor before or after the filter?

**DONOTDELETE**
11-07-2001, 08:42 AM
At the Cost of Syn's, why not FIX the LEAKS?
It can only worsen by ignoring them. And for using 0-40, DON'T. Your engine is NOT designed for the oil wieght. Remember the Lighter, the less lubed ALSO, in the startup.
Spare yourself the $$$ of Syn and just fix the leaks and get Chevron/SOHIO 20-30 and Add Energy Release to the oil for EVEN better Viscosity protection and increased compression assist.
Just an idea. http://www.freshalloy.com/ http://www.freshalloy.com/

**DONOTDELETE**
11-07-2001, 10:33 PM
And for using 0-40, DON'T. Your engine is NOT designed for the oil wieght. Remember the Lighter, the less lubed ALSO, in the startup.[/QUOTE]

Huh? For one thing, I have never seen 0W-40, only 0W-30 - who makes it?

For another thing, thinner oil - BETTER lubrication on startup because it flows throughout the engine more quickly. The compromise is less protection at higher temps and high RPMs, which is why we have multi-viscosity oil.

**DONOTDELETE**
11-07-2001, 11:05 PM
<BLOCKQUOTE><font size="1" face="Verdana, Arial[/img]quote:</font><HR>Originally posted by Scott T:
Huh? For one thing, I have never seen 0W-40, only 0W-30 - who makes it?
<HR></BLOCKQUOTE>

mobil makes it. mobil 1 comes in something like 5 viscocities, 10w30, 5w30, 0w40, 15w50 and i guess 0w30 too, i forget. (they also make special viscocity mobil 1, i think 4w40 or something that you can only get from a BMW dealer). they have a whole site about it, www.mobil1.com (http://www.mobil1.com) i believe, which has surprisingly little information...

**DONOTDELETE**
11-08-2001, 12:09 AM
i said the leaks aren't a problem. the only real leak is from teh valve cover which i don't give a flying crap about. pay attention. the problem is low oil pressure.

<BLOCKQUOTE><font size="1" face="Verdana, Arial[/img]quote:</font><HR>Originally posted by RZ:
At the Cost of Syn's, why not FIX the LEAKS?
It can only worsen by ignoring them. And for using 0-40, DON'T. Your engine is NOT designed for the oil wieght. Remember the Lighter, the less lubed ALSO, in the startup.
Spare yourself the $$$ of Syn and just fix the leaks and get Chevron/SOHIO 20-30 and Add Energy Release to the oil for EVEN better Viscosity protection and increased compression assist.
Just an idea. http://www.freshalloy.com/ http://www.freshalloy.com/<HR></BLOCKQUOTE>

**DONOTDELETE**
11-08-2001, 09:41 AM
<BLOCKQUOTE><font size="1" face="Verdana, Arial[/img]quote:</font><HR>Originally posted by Scott T:
And for using 0-40, DON'T. Your engine is NOT designed for the oil wieght. Remember the Lighter, the less lubed ALSO, in the startup.<HR></BLOCKQUOTE>

Huh? For one thing, I have never seen 0W-40, only 0W-30 - who makes it?

For another thing, thinner oil - BETTER lubrication on startup because it flows throughout the engine more quickly. The compromise is less protection at higher temps and high RPMs, which is why we have multi-viscosity oil.[/QUOTE]
During Winter Scott, that IS the Wrong thing to think. In fact, NO Oil alone in the winter will START protecting the engine,
mostly on a low oil pressure situation, until it is ran over 30 seconds. And if it is ran short distances and shut off for longer than 5 minutes, the thinner oil no longer exists where it needs to be.
Only something which assists the oil by protecting the surfaces of common contact WILL make a difference.
AND mwreck if your OIL pressure IS low, YOU HAVE a Problem. AND as the Crankcase is a point of high pressure and the VALVE/CAM cover is a point of LOW pressure
a small leak is really BIG.
You asked for ideas and opinions. SO there it is. I have only been in the business for 36 years, so I still have alot to learn.
BUT, hey, go forth and enjoy.
http://www.freshalloy.com/

**DONOTDELETE**
11-08-2001, 10:20 AM
<BLOCKQUOTE><font size="1" face="Verdana, Arial[/img]quote:</font><HR>Originally posted by RZ:

AND mwreck if your OIL pressure IS low, YOU HAVE a Problem. AND as the Crankcase is a point of high pressure and the VALVE/CAM cover is a point of LOW pressure
a small leak is really BIG.
http://www.freshalloy.com/<HR></BLOCKQUOTE>

wise WORDS oh GREAT one. http://www.freshalloy.com/

Confucious say: Man standing on toilet, high on pot.

would oil seeping out of the front seal cause low oil pressure? didn't think it would, i mean don't think there's an exclusive pressurised oil supply to the seal itself like there are to the bearings and the oil just drips over it AFAIK. i'm not even sure if it's the front seal or not that's leaking, the oil leaking out of the valve cover kind of flows down the engine. the cover really doesn't worry me at all, it's not as bad as i make it sound, it's just that it's been that way for a while and i don't wash the engine or anything, the oil level stays constant between changes and the reason the cover leaks is because i don't go bothering to change the gasket. i've got one sitting around somewhere, just too lazy.

**DONOTDELETE**
11-08-2001, 10:22 AM
<BLOCKQUOTE><font size="1" face="Verdana, Arial[/img]quote:</font><HR>Originally posted by RZ:

During Winter Scott, that IS the Wrong thing to think. In fact, NO Oil alone in the winter will START protecting the engine,
mostly on a low oil pressure situation, until it is ran over 30 seconds. And if it is ran short distances and shut off for longer than 5 minutes, the thinner oil no longer exists where it needs to be.
Only something which assists the oil by protecting the surfaces of common contact WILL make a difference.<HR></BLOCKQUOTE>

5 minutes? It is generally accepted that you need to wait at least 20 minutes for the oil to drain down just to get a reasonably accurate dipstick reading, and oil will exist in a thin film on internal parts much longer than that - in fact, some premium synthetics such as Redline are well know to cling to engine surfaces for a day or more, ask anyone who has tried cleaning Redline off engine parts during a rebuild. In addition, synthetics flow much better than crude, the winter SAE rating is taken at 0 degrees Fahrenheit but premuim synthetics can flow down to 50-60 below with NO pour point depressants - in fact, a 10W synthetic will flow better than a 5W crude at extremely ow temps.

Also, the common misconception is that the majority of wear on cold starts is due to metal-to-metal contact - in fact, it is due to corrosion by acids which are by-products of combustion, these are normally neutralized by oil which is not present at cold starts. This can be mostly overcome by allowing the engine to idle for a minimum of 30 seconds before driving off. In fact, a lubrication expert (I forget who) wrote that you can add 90-100K miles to the life of any engine just by doing so.

Of course, I have only been working on my own cars and reading everything I could get my hands on for about 15 years, so I probably don't know much either.

[ 11-08-2001: Message edited by: Scott T ]