Pewter C5

I did my first oil change at 1500 miles on my 2001 Coupe, and instantly noticed that the oil pressure was higher thourghout the RPM range :D.

I put the AC Delco Ultragaurd (UPF44) oil filter on mine and used Mobil 1 5W-30 oil. The original filter was the standard AC Delco PF44 filter and don't know if the increase in oil presssure is due to semi-clogged factory filter, or maybe due to the Ultragaurd flowing better. It's obvious that the oil pressure sensor is on the downside of the oil filter -- oil pressure supplied to the engine AFTER is goes through the oil filter.

BEFORE OIL CHANGE (factory filter and oil)
Oil HOT (200 F)
@ idle (600 RPMs), P=18 psi
@ 2000 RPMs, P=30
@ 3000+ RPMs, P=40

AFTER OIL CHANGE (UPF44 and Mobil 1 5W-30)
Oil COLD (80 F)
@ idle (700 RPMs), P=40 psi
@ 2000 RPMs, P=55
@ 3000 RPMs, P=65

Oil HOT (200 F)
@ idle (600 RPMs), P=30 psi
@ 2000 RPMs, P=45
@ 3000 RPMs, P=55
@ 4000+ RPMs, P=60

Also, I have noticed that a slight "knock" that I use to hear at idle when hot seems to be gone. Maybe the higher oil pressure at idle helped the lifters out some?

Hopefully, the lower oil pressure before the oil change did not do any internal engine damage -- doubt it, but it couldn't have helped matters. BTW, the lower oil pressures I saw before the oil/filter change were like that since day one off the showroom floor with 3 miles. So, I guess it's possible that the Ultragaurd filter may have some bearing on the pressure changes.

BTW -- I drained the oil well (raised rear end during draing process) and my car took exactly 7 quarts of oil to put it at the "Full" mark on the dipstick when cold. Also, the dipstick reading is real sensitive to front/rear lean angle of the car. After I did the oil change and ran it for about 10 minutes, then let it drain down again, the level showed about 1/2 qt low with 7 in it. I drove it around some and let it sit all night and rechecked it -- it was right at full with 7 qts. What happened was that the front suspension was not 'settled' after I had the wheels off the ground. It was sitting about 2 iches higher than normal, so that's what caused the oil to read 1/2 low erroniously.



[Modified by Pewter C5, 2:55 PM 8/4/2001]

vette2001c5

I noticed the same thing when I did my first oil change at 1,000 miles. I installed the Ultragard Gold filter and magnetic drain plug. :chevy

mozin

I thought I was the only one with the increased oil pressure from installing the Ultraguard but now I conclude it is normal. My oil pressure numbers before and after the Ultraguard install seem very close to yours. :cool:

It makes me feel better driving with the higher pressure but I doubt the factory filter pressure would do any harm. :chevy

Tom

Pewter C5

mozin -- so from what you said, it sounds like the increased oil pressure is mainly due to the Ultragaurd filter. Someone on another board said he changed his oil/filter at 500 miles because of low pressure. He opened up the factory filter and found all kinds of black crude. He didn't say what new filter he used, but since he didn't mention it being an Ultragaurd, I assumed it was the standard PF44. He said his pressures increased too, but not quite as high as mine, but close.

Has anyone noticed a big increase in oil pressure after the first oil change and used the standard AC Delco PF44 filter too? I'm wondering if GM uses alot of engine asssembly lube on these motors and it chokes the factory filters pretty badly?


[Modified by Pewter C5, 4:24 PM 8/4/2001]

Viprklr

I too am running higher oil pressures after changing to the Ultraguard. I was not as low as some of you all to begin with, but I am now much higher than before. Do I see a trend?!?!? :lol:

Dave68

I may be missing something here, but normally a free-flowing system would produce lower, not higher pressures. When your catalytic conver gets plugged, backpressure goes up, not down. It's be good to know exactly where oil pressure is measured. Now, more oild should crank-up the pressure. I have read that the oil-capacity of my 2001 is 6.5 quarts. Adding 7 quarts would increase pressure, but gaskets may suffer accordingly. That is why you should never overfill beyond a certain amount.

david kendall

I saw the same thing on our 2000 coupe;
In the last week before the appointment for the 1st oil change I was so neurotic :crazy: about it that I'd press the accelerator pedal a bit (A4) at short-timed traffic lights, and additionally change into neutral at long-timed ones.

saveTheWave!!

:Dave and krystyna

Pewter C5

Dave68 -- your are missing something here :D. You first have to know that the oil pressure sensor is located AFTER the oil filter. So, when a less restrictive filter is put on, the oil pressure will increase at the pressure sensor. This is because there is less of a pressure drop across the filter. Imagine if the filter was nearly completely clogged. In this case, there would be almost zero oil pressure on the downside of the filter, and hence almost zero oil pressure or flow to the engine.

Also, the amount of oil in the oil pan has NOTHING to do with the oil pressure. The oil in the pan is just laying there, and gets sucked up by the oil pump. The oil pump pressureizes the oil and sends it to the engine. The literature for the 2001 Vette may say it takes 6.5 qts, but in reality it takes exactly 7 quarts if the oil is drained properly and the filter is changed.

BTW -- here's one to ponder over. The Vette owner's manual says to overfill the engine by 1 qt if your going to go race it ... hummmm.

MDT

[QUOTE]
Also, the amount of oil in the oil pan has NOTHING to do with the oil pressure. The oil in the pan is just laying there, and gets sucked up by the oil pump. The oil pump pressureizes the oil and sends it to the engine. The literature for the 2001 Vette may say it takes 6.5 qts, but in reality it takes exactly 7 quarts if the oil is drained properly and the filter is changed.
[QUOTE]

True dat. :D

Good luck.
Mark

Dave68

I still think that overfilling will increase pressure to a point where gaskets can no longer seal. Also, it's odd that the manual would mention racing if the warranty is null and void if the car is raced. There was a post about this recently, where a dealership would not honor the warranty after evidence of racing was discovered.

BTW, my 01 coupe has approx. 1200 miles on it (original filter) and the oil pressure (hot) is as follows:

Idle: 32
2000 rpm: 44
3000 rpm: 54

:cheers:

Avanti

All "modern" cars I've seen have a bypass system to assure there is no oil starvation with a clogged oil filter. I assume even GM engineers have figured out how to do this Granted, a filter clogged or with poor flow characteristics will hinder flow and pressure until the point where the bypass "kicks in."

I too went to the better oil filter on my '01 for my first oil change at 800 miles. BTW, I opened the original filter and saw less metal (or anthing else, for that matter) than I have ever seen in a new engine filter (also, I found the same to be true of the other drive fluids when I changes them at 1000 miles). However, back to the filter change--no pressure difference on my car. The oil pressure stayed the same, somewhat in-between what some of you have found with the filter change. Now, at about 3300 miles, following a 2500 mile trip I changed oil and filter again, and given the summer ambient temperatures in the South I decided to use up some of the 10w-30 Mobil One I had on hand for another car I just sold. Viola, I find I now run almost identical pressures (again, with the better filter) that those of you are experiencing with your filter change alone. ???

When I change oil and filter again at 5000 before the onset of cooler weather I'll see what happens with the oil pressure. As for seals at risk of higher pressures, unless there is something unique to the LS-1 I'm unaware of, this should not be an issue with the pressures noted here. We run higher oil pressures in vintage racing engines (& 30+ pounds of turbo boost) with some original type seals (much poorer than today's designs) without problems.

Fortunately, in street cars oil pressure can vary considerably without problems.

Pewter C5

Dave68 -- It seems like most guys have lower oil pressure than yours with the original filter and oil. I can't explain that, but maybe some of these filters get semiclogged up from crap inside the engine. As I mentioned earlier, someone on another Vette board cut open his factory filter and found all kinds of black goo inside it. His idle pressure when hot was down to ~15 psi.

I hate to say it again, but the oil level has nothing to do with the oil pressure in these engines. If it had 2 qts or 8 qts of oil in it, the pressure would be the same unless the oil pump sucked air, then the pressure would go to zero.

As far as the "add 1 qt for competition driving" -- sit down with your owner's manual for an hour and read through it. You'll learn all kinds of neat things you never knew before :D.