oil pressure drops in WOT....?

[mk3-4-me]

ok so i just noticed today that when i put the pedal down and go WOT my oil pressure will drop to about 15-20 psi. Idk why it would do that. Is it something to worry about?

I just rebuilt the motor about 2k miles ago. I got the engine already built, then rebuilt it. I was told that it was a new factory oil pump, and when i took the engine apart the oil pump was really clean and looked new. So what could cause this, or is it normal?

At idle im at about 12 psi and cruising at 2k rpm im at about 30 psi. Cold start up goes to 40 psi then after i drive a bit it comes down to about 12 psi at idle.

thanks!

 

[hvyman]

You reused the oil pump on a rebuild?

How long has this been happening?

 

[Greyscorpion]

Have you checked the oil level?

 

[mk3-4-me]

Ya the guy who built the motor before me only put about 10k on it before I rebuilt it. And he bought a new factory Toyota oil pump for it, and I reused that. I shimmer the oil pump 4.6 mm. And idk how long it's been doin it to be honest. When I'm in WOT I'm looking at all the other stuff goin on. Lol

And I havnt checked it since I last drove it, but earlier this morning I checked and it was full. That's another thing I was going to ask about.

When check my dipstick, if I pull it out and clean it then dip it in quick and check it, there will be oil along a side of it (to full mark) and no oil on the rest. But if I let it sit in there for a min or 2, it will have oil all on it going up to the full mark. Sometimes there will be a spot of no oil onthe dipstick. Im thinking maybe the colder oil temps when it's been sitting and maybe the hatching marks on the dipstick aren't as "grippy" as before...? Lol any one experience this?

 

[IBoughtASupra]

No. Change your oil and full it with five quarts.

Second, why did you shim the oil pump? JZ owners actually modify the oil pump to lower it's oil pressure that it produces at higher RPMs since it blows out the front main seal? If they didn't modify it to lower the oil pressure, they add a screws around the ring that holds the seal in place.

 

[Greyscorpion]

You want to check it after the oil has had some time to settle. But yes change the oil and full it with 5 quarts.

 

[CyFi6]

Oil pressure is affected by RPM (among other things), but not throttle position, so if its strictly dropping when you go WOT I would be more suspicious of an electrical issue than I would a mechanical issue. Get a mech oil pressure gauge hooked up and verify that the one you are watching is accurate.

 

[mecevans]

What brand oil filter do you have on it now?

 

[spooln30]

I've shimmed many 7m oil pumps with never a problem. I never heard of 2j guys(me being one) lowering their oil pressure to stop a FMS from blowing out. Matter of fact the modded 2jz oil pump SP and Boost Logic sells is shimmed, the return hole made larger and 3 set screws installed by the FMS. Never heard or seen a "ring" for the seal. Many 7m guys will shim the pump. I actually got the specs for the washers from IJ 8 years ago.

Hamid call me tomorrow I think I know why your oil pressure is dropping off. Till then stay off the gas.

 

[IBoughtASupra]

It's done by SP. I meant to say, it goes around the ring of the seal, not that they add a ring.

 

[mk3-4-me]

Oil pressure is affected by RPM (among other things), but not throttle position, so if its strictly dropping when you go WOT I would be more suspicious of an electrical issue than I would a mechanical issue. Get a mech oil pressure gauge hooked up and verify that the one you are watching is accurate.

I have a mechanical one already in. I wouldn't trust any stock guages for anything! Lol

And I have a supertech oil filter in.

And ok I'll txt u today when im at work Keith.

 

[mecevans]

Change out that filter for a Wix. It most likely is going into bypass.

 

[mk3-4-me]

My mechanical oil guage has a slight leak. Pretty much just has a dab of oil sitting by the fitting. It wouldn't just be leaking out of there more when it builds pressure, thus causing a lower oil pressure reading would it?

I mean It goes to just about 40 psi on a cold start up, so I know it will hold that just fine.

 

[mk3-4-me]

Really? What is and why would it go into bypass?

By the way, I have a sandwich plate with a bigger external oil cooler if that makes a difference.

 

[IBoughtASupra]

I always get a Toyota filter. I don't like aftermarket oil filters.

 

[mk3-4-me]

Ok but will a filter cause this? I got a good read on here about supertech filters. I believe j-dub mentioned that somewhere I read.

 

[hvyman]

Toyota filters don't filter well at all. Wix or pureone are the ones to get. And 7m pumps should be shimmed.

 

[mk3-4-me]

Ok well any idea what would cause my oil pressure drop?

 

[mecevans]

Start with the Wix oil filter, then go from there.

 

[mk3-4-me]

Damn. It sucks trying to get my oil filter off!! Lol

So what supertech isn't good? I read that's one of the better oil filters....?

But I guess I'll try it. I'm wanting to change my oil to GC 0w-40 now anyways. I have about 2000 miles on my build so far... I'm just worried that something will happen! Lol I read all these stories about people switching to synthetic and then they get rodknock.... Ive already dealt with rodknock twice. Lol