Over the last few months, I've rebuilt my motor and reinstalled it in the car around Thanksgiving. I've driven it a few miles and it seems to run ok, although I haven't taken it above 4500-ish rpm, yet. Every 2-3 engine starts, it throws code P0524: "engine oil pressure too low". My aftermarket oil pressure gauge says I have about 90psi at the oil filter (on a sandwich plate) at startup, and around 30psi at idle after warmup. The low oil pressure 'idiot light' has never come on, so I removed it and installed a mechanical pressure gauge just to double-check my electronic gauge -- I get almost 100psi at startup and 35psi at idle after warmup. I've removed the vtec solenoid and verified that the screen is clear (it's brand new). Yet, I still get that pesky code. The only other thing I can think of worth mentioning is that I'm still fighting to get all the air bled out of the cooling system.

Anyone have any ideas?

On the side of the vtec solenoid, there is what appears to be a pressure sending unit.
Can I remove that and install my mechanical gauge there long enough to verify pressure to the solenoid? Alternatively, I have another motor that I could pull the whole thing off of and swap in.

 

what was rebuilt on the motor?

 

I replaced all of the bearings, polished the crank, and did the valve seals, retainers and keepers. I did not remove the pistons.

 

Could just be a loose connection to the oil pressure sending unit or bad sender. According to the manual you can put a mechanical pressure gauge there. Pressure should be 36 psi at idle and 85psi @ 3000 rpm, those are minimums according to the manual. Also, those are warmed up pressures, i.e. the fan cycles on twice at least. Good luck.

 

Yep, that's where I installed my mechanical gauge, and took my readings. All signs point to plenty of oil pressure at pressure switch for the oil light on the dash. There has to be another oil pressure sensor somewhere, though, that the ECU is reading in order to set that code. My question is -- is that sensor on the side of the vtec solenoid assembly? I suspect it is.

 

Disclaimer: a few beers in, not a mechanic

But if Im not mistaken the vtec solenoid is only functional at vtec when oil pressure activates it. And if you haven't gotten it over 4500 then wouldn't it be unrelated to the vtec solenoid........

 

try a new oil pressure sensor...they are relatively inexpensive...or swap one with another s2k to see if that is the problem

 

Try a new OP sensor.

 

You need the a different scan tool that can correctly define the DTC.

P0524 does not exist on a S2000.

I'm guessing you've actually got a P0411

 

Now, that makes sense, as my scan tool isn't having any luck clearing the code. I'll borrow another one tomorrow and try it. When I did the blink code trick, I got 6-0, which is 'air pump', according to modifry's page.