Low / No Oil Pressure - Corolland: the Toyota Corolla Forums

Any clues? I have a 2001 1ZZ-FE out of a Corolla with a fresh long block. When installed in the car, as the engine warms up (about 20 min.) the oil pressure drops to "ZERO". Remove the engine and run on a test stand with oil heated to 150f being driven at 500 rpm it holds oil pressure at 45psi for over 1.5 hours. Reinstall in car and oil pressure drops to "ZERO" as it warms up (agine about 20 min.). In both setups, the engine driven oil pump is providing the oil pressure. Any tips to solving my mystery?

Thanks, c5d

Out of the car, the pressure is good; inside the car, the pressure is bad. Question: what instrumentation did you use to gauge pressure? Same as in the car? If not, there's where you should look. If so, some other factor--most likely electrical--is causing your oil gauge to go wonky.

2nd Gear, Thanks for the reply!

I have installed three different mechanical gages along with the oem oil light. All four indicate the same... 75 psi / no light at start-up and no oil pressure with light on after oil / engine is at operating temperature, while it is in the car running on its own power. As the oil pressure goes down I can hear the timing chain start to slap. This motor is currently on test stand just as a long block with oil pickup tube and oil pan installed. Also the oil control valve is in place with no electrical hook-up. The motor is being driven by a eletric motor at about 500 rpm and 5w20 oil going through a preheater circulating into the engine at 150 degs f. This is as close as I can get to simulating the in car installation. With this set-up, I do not have crank or cam sensor installed so the oil control valve (OCV) is just a plug passing oil through it with no vvt control, which is the biggest difference between the two set-ups (in car / out of car simulation). One of the mechanical gages used has been used in the car and on the test stand. While on test stand from start, engine has 45psi of oil pressure @ 500 rpm for 1.5 hours with no fluctuation. Could it be a bad OCV? I have not questioned the crank and cam position sensors since I have not gotten any OBD II codes indicating problems with the two sensors. I did get a P0118 (engine coolant temperature sensor) but it cleared as soon as coolant started to circulate. I have not only turned gray over this one... now I'm going bald too! I hope all this info will spark some tips to solving this oil pressure problem. Thanks, c5d

As long as you see pressure at the pump outlet - you are fine. Don't worry about the OCV at this point - just have to see if the oil pump is making pressure. Valvetrain chattering/thrashing on a 1ZZ-FE is unfortunately pretty normal - this engine is known to be quite noisy. Might try a heavier weight oil (5w-30) or something with some VI improvers that will help with HP/HS.

That said - 45PSI at 500RPM is pretty high, unless you are reading the stand RPM. At idle (650-750 RPMs), these engine usually get about 4-5PSI of oil pressure. 45-75PSI is something I'd expect at 2000-3000 RPMs. Have to make sure that your standalone oil pressure gauge has that low of a resolution. Most of the gauges that I've seen are not good at discriminating at low pressures.

Also depends on how you connect the supplemental gauges - a T off of the OEM sending unit or did you just pull the OEM one off and install the aftermarket one?

fishexpo101, Thanks for the reply!

I have installed this engine this past wkend using a certified pressure gauge from my plane, it reads 1 psi increments. One of the same gauges I have used when I started with this project. I use 5w-30 oil as recommended by manufacture. All pressure gauge or light installations have been stand alones, no "t" fitting. This time around has not solved the mystery, but I do have good oil pressure(13psi at 700 rpm for 2 hours). Not sure of what made the difference this time but the car is rolling and the engine no longer sounds like the timing chain is slapping like the last time. Wished I had the knowledge of what caused the no oil pressure for future reference, but for now, I have one more project closed and off to the next project. FYI, for anyone that might consider having a short or long block built. I used City Motor Supply out of Dallas, TX . I only add this because they worked with me on this the hole way though at no additional cost. They stood behind there work.