Oil pressure drops at WOT

[97Formula]

I've seen a few threads on other message boards where the oil pressure actually drops for a little bit then comes back (drops around 4000-4500rpm, and at 5500 comes back up). Some even say it's just a typical thing for the LT1, while others say it's not normal.

I just recently noticed mine doing this (never really looked at the oil gauge before so I don't know how long it's been doing this). But at times, it can drop as low as 35 at WOT around 4500rpm, then go back to 50-55 at around 5000-5500rpm (when accelerating from almost a dead stop). WOT on the highway (passing 45 - 70mph) the oil pressure only drops a little bit at the same RPM's.

If I drive normally (up to 3/4 throttle), the oil pressure maintains 40-45 psi the entire time, then drops to 18-20 psi at idle (already confirmed that is normal when warm/hot).

Any thoughts? Do I need to take it to a repair shop yesterday? If so, any good shops in Central NJ (Trenton area) that would be able to fix? Thanks!

Car has 34300 miles, Mobil1 5w30 and K&N HP2002 filter (changed about 100 miles ago)

[NJSPEEDER]

In the other cases that people said it is a common occurrence did they mention if it is a gauge/sending unit issue or if it is something with the pump?

Seems an odd issue to have.

[LTb1ow]

Too little oil, or usually a high volume pump in a stock pan

[NJSPEEDER]

Is the stock LT1 pan baffled or anything that would restrict volume around the pick up?

-Tim

[LTb1ow]

I'm a little hazy on stock stuff but I believe it's only a windage tray under mains.

Pull pan and investigate but having a shop do anything is gonna cost you a small fortune

Personally, I would get a reliable mechanical Guage ge and watch oil pressure, then evaluate. There is a port above the oil filter to tap into for reference pressure

[NJSPEEDER]

That brings us to an easy way to test if it is related to oil running away from the pick up, tap a gauge in and sitting in the driveway rev it up to see if you get the same result on both the stock and the tapped in gauges.

If the same thing doesn't happen sitting still on fairly level ground then you may just be looking at oil sloshing away from the pick up while accelerating. If it shows the same on the stock gauge but not the tapped in that would most likely relate to the sending unit. If you see the pressure drop on both gauges then you need to dig deeper for a solution.

[WildBillyT]

I've seen a few threads on other message boards where the oil pressure actually drops for a little bit then comes back (drops around 4000-4500rpm, and at 5500 comes back up). Some even say it's just a typical thing for the LT1, while others say it's not normal.

I just recently noticed mine doing this (never really looked at the oil gauge before so I don't know how long it's been doing this). But at times, it can drop as low as 35 at WOT around 4500rpm, then go back to 50-55 at around 5000-5500rpm (when accelerating from almost a dead stop). WOT on the highway (passing 45 - 70mph) the oil pressure only drops a little bit at the same RPM's.

If I drive normally (up to 3/4 throttle), the oil pressure maintains 40-45 psi the entire time, then drops to 18-20 psi at idle (already confirmed that is normal when warm/hot).

Any thoughts? Do I need to take it to a repair shop yesterday? If so, any good shops in Central NJ (Trenton area) that would be able to fix? Thanks!

Car has 34300 miles, Mobil1 5w30 and K&N HP2002 filter (changed about 100 miles ago)

How much oil did you fill it with? If it's overfilled you could get windage issues.

[Blackbirdws6]

Stock pan just has the windage tray. Make sure the oil level is correct as mentioned.

[97Formula]

Stock oil pump, pan, and pickup. Dipstick is right on the full mark.

[97Formula]

Ok this is strange, but I just came across a few WOT videos I took of my car (dash view) and what do you know.....it seems to have always done that (one video was a few years ago, another was almost 10 years ago). And my oil has always been full between oil changes (never had to add oil), and very, very few metal particles are found on my magnetic drain plug each time.

So I guess I'm ok. Still kinda strange that it drops around 4500-5000 briefly then comes back as it approaches redline.

[Pampered-Z]

As the RMPS go up quickly you pump most of the oil to the top end so pressure can drop slightly until oil gets back down to the pan. It's actually very common with a stock volume of oil.

You have good pressure, your not sucking the pan dry.

[NJSPEEDER]

I know a lot of the road race and autocross crowd tend to run gen1 small blocks 1/2 over. The thirdgen stock pan is a truck pan and a bit deeper at the back so it isn't a problem.

Is that safe with the stock LT1 pan or will it create too much windage?

-Tim

[97Formula]

As the RMPS go up quickly you pump most of the oil to the top end so pressure can drop slightly until oil gets back down to the pan. It's actually very common with a stock volume of oil.

You have good pressure, your not sucking the pan dry.

Hmmm....doesn't seem to happen at all if I rev to 4500 when not in gear (park/neutral). Must be the oil sloshing around (didn't the LT1 SS or Firehawk have something special in their oil pans to prevent this)?

[LTb1ow]

AFAIK, the SS or any aftermarket package had nothing power train upgraded.

Unless you want to call an oil cooler an "upgrade"

[FlyingDutchman]

Was watching some videos I have on my computer last night and noticed my oil pressure drops under acceleration too! Camera was on the passenger side so I can't really determine what the readings are, but you can def see it. Have you done anything to fix it yet, or just leaving it be?

I saw this thread (http://ls1tech.com/forums/lt1-lt4-modifications/1659351-oil-pressure-drop-wot.html) Seems like one guy fixed it with a moroso oil pan and Hv pump with pickup. Since I'm gonna pull my motor, wondering if I should upgrade the pan or not worry .. Right now pump/pan are stock.

[97Formula]

97camaro,

I kinda left it be, since I hear lots of mixed opinions ranging from "it's normal", to "as long as it does not drop too much and can recover", and finally "no, this is not normal at all, fix it yesterday, etc". In my case it seems to have always done it, and no real harm has been done.

I think it's the oil sloshing around especially when accelerating hard (especially if the parts in that video solved the issue). Right now I have no other reason to tear into things so I really think I'm gonna leave it alone.