Here is the scenario...

My car-
103,000 miles
internally completely stock
oil pressure hot at idle..touch over 20
op at cruise, over 40+
op at wide open throttle, right at 60

Car #2

18,000 miles
hot cam kit(rockers, cam, timing chain), underdrive pullies, headers.thats about it
oil pressure at idle when hot..20
op at cruise..40
op at wot...just a touch over 40 and we get a sharp 6-7lb drop at wide open throttle around 4500 r's, then it jumps back up around 40 before the shift.
For some reason, slowly bringing the r's up in first it approaches 60, but not quite..

Car # 1 uses 10w30 castrol syntec

Car # 2 uses pennzoil straight 30 weight(complete **** IMO)

So why the low oil pressure and drop @ wot ?????

 

On the first car things look good, on the second one they look good until you get on it...you could have a sending unit going bad...may be worth checking into...my IROC had a similar problem...although it wouldn't show any pressure till you got on it...it was bearings though...but...sending unit can cause problems like you've described...

 

ttt..any other ideas?

 

maybe something to do with the ****ty oil he is using? I think he should switch back to mobil 1 personally

 

Catrol makes good oil...I doubt that has anything to do with it, hell even your ****ty oils are decent for the first 1500 or 2000 miles....so if he does maintenance then he'll be ok...I run either castrol or quaker state in my car and never had a problem...

 

ttt

 

Castrol might make good oil, but it's not the brand...its the "straight 30 weight" that sucks. You need to get a good multiweight oil in there for starters.....may not fix the problem but the engine will last a hell of a lot longer.

Now about your oil pressure, one thing I noticed with my LT-1 with the hot cam is that when I would punch it in 1st gear, it had such good acceleration that it would slosh the oil away from the pickup tube so that I would in some instances actually lose oil pressure altogether. Bringing it up slowly it was fine. The only way to fix this is to make the pickup tube get closer to the bottom of the pan, run a pan that holds more oil, baffle the pan better, or change to a heavier oil like 15w-50 so it doesn't slosh away as readily. I ended up using the 15w-50 synthetic (cause it was the easiest to do) and it worked well.

Good luck

-Dave C. '97 Z28

PS: it would be a good test to see if the car does it in third gear, or only in First. If it does it only in First gear then I would look toward the oil slosh as the problem.

 

Dave I have NEVER heard 30 weight was bad oil...in fact I have heard and read that it is the BEST many times over. It has the best lubricating properties compared with all the other weights...where'd you hear it sucked?

 

straight weight and pennzoil suck IMO..but anway, another issue that no one is getting at is the fact that his oil pressure SUCKS..barely over 40 at wot..my stocker is 60..that can't be good. I doubt that the slosh has anything to do with it as when he gets in it, it moves up and not down, its only at the top of the rpm band that it drops.