My oil pressure gauge has a tendency to drop when my engine is at low RPMs such as idle. If I feather the gas it will jump up to normal pressure. This is somewhat an intermittent problem. My car burns through massive amounts of oil (I am saving up for a new engine), I noticed that when I added more oil was when the pressure started dropping, but when it was low on oil it seemed to have the correct pressure. Any ideas what is going on here? Oil pump failing?
Your oil pressure gauge is supposed to drop at idle and increase with throttle. Your oil pressure gauge shouldn't be dropping to 0 but somewhere inbetween. Took this from Entrax's post.
if you mean the stock oil pressure gauge...that is old and not very reliable. Also the sender can be faulty, I had both occasions . An aftermarket oil pressure gauge which you can screw on the original senders' place is not so expensive and much more reliable.
I know I'm reading and replying over 12 months from the last post, but I found that with certain oils in my Celica's 1st gen 3sge motor, that at sustained legal high speed running and coming to a standstill, for road repair reasons, my oil pressure would drop alarmingly, but after a few minutes the oil pressure would come back up to 'normal' operating pressure. Obviously the coolant system is dumping heat out of the block, allowing the oil temperature to drop, and thicken back up to normal viscosity. Perhaps these more modern oils are not quite right for our type of motor, or it's a reason why Toyota fitted various types of oil coolers/heat exchangers to later versions of "S" series of engines. I'm using Castrol Magnetec 15w50 semi synthetic.
On this site there is no such thing as a "dead thread" How many km do you have on your motor? Stock Euro 162's do have oil coolers fitted and yes later motors including the 4S and 5S have them too. All the later motors also have a bigger oil pump based on the ST165 pump. I think what you're describing here is a combination of a worn oil pump and worn bearings, no oil can survive under those conditions and the drop can be quite alarming. My stock 190 000km motor would do the same thing on the track and after 7 laps the pressure would go to zero. I used a gen2 block with oil cooler to eliminate this as well as a bigger GTE pump and careful monitoring of the bearings and the problem went away. If your pressure is high and then drops to zero suddenly - beware, this is a deadly symptom of a relief valve sticking and has killed many 3S motors
If you are answering my question above it is too late lol that was for my old convertible which ate a bearing shortly after but that's okay seeing as how I now have an All-Trac!
Yes, I keep an eye on the (yeah, I know, inaccurate) standard oil pressure gauge. I only bought this car at the beginning of the year, because 1) it was cheap, 2)The engine's cylinder pressures were reasonably good, around 170psi, 3) minimal rust, 4) drove ok, and 5) It's an SX 3SGE. The speedometer reads 330,000km but I don't know if it's the original engine, or if it's been re-ringed and bearinged. The gearbox feels sweet as, with no grawnching and no 5th gear popout issues (if this box ever suffered from that symptom) looks like it has been split open at one time. I wouldn't be surprised if the oil pump's a bit worn, but still keeps pressure up under suburban driving duties, I'm just using it as a 'cheap run about' and keeping my Ranger for more economical driving conditions (ie freeway). I drove the Celica about 200km to show it off to a relative, and that's when I noticed that the oil pressure gauge shows a lower than normal reading, but would soon come back up, I just feathered the throttle a bit to make it idle a bit faster for a few seconds. I never was able to afford one new, bought it's little brother AE82 Twincam, and later a AE92 Seca SX. So I'm rewarding my midlife crisis. Funny thing is, my Ranger has got more acceleration, it's a 3ltr twincam intercooled Turbo Diesel !!!! What would be a reasonable oil cooler, the Toyota heat exchanger that Toyota put on their S series motors (will it fit on?) and route water hoses from the heater cct, or a stand alone air to oil cooler in front of the radiator. The heat exchanger would do double duty and warm the oil up, from cold, too?
Scary how accurate I can be? The oil warms pretty quickly by itself An aftermarket cooler & take off plate I think is better than the water cooled types but pricey. The gen2 and FE type coolers will fit your motor but you need the steel water pipe, the cooler and the longer bolt to bolt it down There may also be an issue with clearance to your starter, another reason to go aftermarket
