Oil Pressure
01-31-2008, 06:16 PM
#26
That might indicate an oil foaming issue... the oil pump is too busy collapsing bubbles then pumping oil
the basic background to that are oil air bubbles break when the oil surface tension is exceeded and a way to improve that is to put impurities in the oil to give the surface weakspots. The impurities or 'antifoamant' agents are usually silicone and float around in the oil (not in solution). The have been know to be filtered out by filters sometimes and synthetic oils have a harder time with foaming because the oil lacks impurities to begin with.
the basic background to that are oil air bubbles break when the oil surface tension is exceeded and a way to improve that is to put impurities in the oil to give the surface weakspots. The impurities or 'antifoamant' agents are usually silicone and float around in the oil (not in solution). The have been know to be filtered out by filters sometimes and synthetic oils have a harder time with foaming because the oil lacks impurities to begin with.
like i said, after i changed it, it never happen again.
From that time, I keep my oil change schedule tight as hell. and looking at the oil press gauge every couple minutes or so.
Wait for next summer to come ~ So I can tell if it has anything to do with old oil.
01-31-2008, 07:16 PM
#27
Got Another Rotary
Thanks Jax! You certainly explained it better than I could.
On BITOG there is debate over the 5W30 weight Royal Purple as members have shown that it shears through wear. For those of us changing oil every 3,000 miles though, I don't think it's a big deal. However, because of the longevity concerns, I use Mobil 1 5W30 in all cars that I maintain except for my RX-8 since they're all on 7,500-10,000 mile drain intervals.
nycgps, don't forget you were using Shell synthetic in your sparkplug thread and had previously used Mobil 1. I wasn't sure which oil you were reporting.
On BITOG there is debate over the 5W30 weight Royal Purple as members have shown that it shears through wear. For those of us changing oil every 3,000 miles though, I don't think it's a big deal. However, because of the longevity concerns, I use Mobil 1 5W30 in all cars that I maintain except for my RX-8 since they're all on 7,500-10,000 mile drain intervals.
nycgps, don't forget you were using Shell synthetic in your sparkplug thread and had previously used Mobil 1. I wasn't sure which oil you were reporting.
As for the shearing BITOG likes to talk about, is not really an issue unless someone is running 7500+ mile oil changes and no one should be doing this with an 8 (I do 2500, but see 3750 as a good number as well, and 5000 as a max) because of our fuel dilution issues.
M1 is a good synthetic, but gets some grief on BITOG because they went from a primarily Group IV base stock to a group III blend (with some IV and V) and are charging the same or more. That said, it is a good oil.
Personally, I am most impressed with Pennzoil Platinum (Group III/V blend), as it is showing extremely good wear numbers in every vehicle using it and is especially good in engines with heavy fuel dilution (like VW/Audi) where many other oils are not working so well. The only oil I would pick over PP right now would be Amsoil or Redline, but they are quite a bit more expensive and cannot be found locally.
01-31-2008, 07:21 PM
#28
I dunno I think Amsoil sells good oil, they update their specs really fast and stuff. but for some reason they love to do those *chain store kind of selling* thing, I got their ATF once for my bro's SE-R (cuz it calls for Matic-K spec, only Amsoil has it that time)
Redline yeah... is on the expensive side, but they're group V so I guess that explains why.
I see PP everywhere. I might try them after I try Redline. (Currently using Shell Full Synthetic)
Redline yeah... is on the expensive side, but they're group V so I guess that explains why.
I see PP everywhere. I might try them after I try Redline. (Currently using Shell Full Synthetic)
02-01-2008, 11:45 AM
#29
Got Another Rotary
I dunno I think Amsoil sells good oil, they update their specs really fast and stuff. but for some reason they love to do those *chain store kind of selling* thing, I got their ATF once for my bro's SE-R (cuz it calls for Matic-K spec, only Amsoil has it that time)
Redline yeah... is on the expensive side, but they're group V so I guess that explains why.
I see PP everywhere. I might try them after I try Redline. (Currently using Shell Full Synthetic)
Redline yeah... is on the expensive side, but they're group V so I guess that explains why.
I see PP everywhere. I might try them after I try Redline. (Currently using Shell Full Synthetic)
Redline is a great oil as well, but being a polyol ester (Group V) based oil, you cannot run oil analysis samples on it until you have run it a few oil change intervals (OCIs) as esters are great cleaners and will pull all of the built up dirt into the oil until it gets you motor clean - distorting any oil analysis run early on.
I may try one of these someday, but I still like short OCIs, and these cost enough more to make a significant difference over $5.75/quart PP at Wally World.
02-01-2008, 11:54 AM
#30
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BACK to pressure question: What's the highest and lowest you guys have seen?
Yesterday:
Low - 8 psi
High - 80 psi
Yesterday:
Low - 8 psi
High - 80 psi
12-08-2008, 08:18 PM
#31
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ok thread revival because i also have the same question as jedi... today the lowest i seen was 8 psi and highest was around 78 psi and it seems like my car was idling a little rougher when the psi is low. i changed my oil around 1,700 miles ago and does it mean my oil needs to be changed again or is my oil too thin? by the way i am using 5w20
12-08-2008, 10:23 PM
#33
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only 5w-30 for me these days. 
12-08-2008, 11:17 PM
#34
Im using Redline 10w40 right now (and I top it off with Syntec 0w30 about 2 weeks ago, 1/2 quart I think ?)
Highest oil pressure I've seen is about 530 kPa (Which is about 77 psi), when it was new, I think I got some highest number
My car is due for another oil change real soon. but I will do that after my trip to Asia
Highest oil pressure I've seen is about 530 kPa (Which is about 77 psi), when it was new, I think I got some highest number
My car is due for another oil change real soon. but I will do that after my trip to Asia
Last edited by nycgps; 12-08-2008 at 11:24 PM.
12-08-2008, 11:27 PM
#36
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don't forget what you're supposed to bring me back!
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