Posts: 1561
Joined: 8/24/2005 From: Brooklyn, NY Status: offline
ah, I know, couse it cheap. How ever I'm going to change again in like 1500Miles, couse I used Seafoam in crankcase. So next oil change is going to be fully syntetic, and tranny oil too.
I have a '93 100CS quattro. My oil pressure is at the highest, 5 bar. When I'm stopped at a traffic light sometimes the needle goes down to 2 psi. I use Castrol 10W-30. Should I use synthetic? The car has 160k miles on it. Thanks.
The viscosity of your oil is going to directly effect your oil pressure.
As long as it does not drop off to 0, then your pump is gone and well so is your car.
I know this is not a Diesel, but diesels are super tempermental about changes to oil viscosity. I used to have a truck that when I changed the oil it would drop to nearly no pressure. After a month or two (viscosity goes up) the pressure would sit right on the "normal" line on the gauge. Using the Seafoam product probably grossly reduced your viscosity since it is meant to break up sludge right (which makes me wonder why you would use such a product?)
Now if you want to talk about the positive and negative effects of low viscosity oils... well make a new poll. Personally, I go with a 10W30 in my Audi because as great as these 0W50 and all synthetics sound, I aint buyin it. PS MSA10, 10W30 got my car to 180K and yours to 160... I think it will be alright.
Posts: 1561
Joined: 8/24/2005 From: Brooklyn, NY Status: offline
at 2000 RPM I get around 3bars with 90C oil.
I use seafoam to just clean a bit. You know from previous owner, you never know what he used. so I just do to make sure that evrything is clean and functioning.
and castrol syntec is not syntetic, however it like dyno oil but very high level.
the regular mobil1 oil with gray cap is true syntetic.
and I did not see almost no sludje, but you never know.
Posts: 758
Joined: 3/9/2004 From: Swamplands of NJ Status: offline
2psi is way too low. To accurately measure oil pressure you have to use a calibrated mechanical or electrical gauge. The factory mounted gauge on the dash is not accurate especially after many years of service.
Posts: 1561
Joined: 8/24/2005 From: Brooklyn, NY Status: offline
quote:
ORIGINAL: 0fframp
2psi is way too low. To accurately measure oil pressure you have to use a calibrated mechanical or electrical gauge. The factory mounted gauge on the dash is not accurate especially after many years of service.
Posts: 1561
Joined: 8/24/2005 From: Brooklyn, NY Status: offline
ohh, ye I have checked the mobil website and I got that clean500 is conventional oil, like castrol syntec. and the clean7500 is syntetic blend. the clean high milage is conventional blend. the mobil1 is syntetic and mobil1 extended performance is syntetic with extra cleaners.
well I will probably get, mobil1 0w-40 or 5w-40 or mobil1extended 10w-40
Basically I have now cSt @ 100C 10.6 thats on 5w-30 The next level is around 14.
so any oil with an end of 40 is good for me. I wana still higher presure.
the 0W-40 cSt @ 40C is 80 while 5W-40 has 102
Note: the lower the Cst number the more freally it flows. our engines have hydralic lifters the lower the cSt the better they will fill up.
Ok so then my 3 seconds of lifter noise on morning startup isn't a terrible thing then?
I'm at 147,000 on my 1987 2.3 liter naturally aspirated 5 cylinder.
Because I do autocross (first time in this car this Sunday actually), I really want to clean the oil passages, change out the oil with something a little thicker (10/50 maybe), and swap out the oil pump for something with a little more pumping pressure. I may end up simply putting on an oil cooler though as too much oil pressure can be a bad thing. I had one lifter giving me a little bit of a hard time after the 3rd the 4th run for a minute while the oil cooled.
Posts: 1561
Joined: 8/24/2005 From: Brooklyn, NY Status: offline
the noise is a terible thing, yours just isnt too bad yet :) what oil are you using now? most of the times, if I remember corectly all you do is just get new lifters, or lower viscocity oil grade.
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Oil presure, your opinion. - 
