[BLstangin]

Went to go on my trip and got bout 70 miles from home and oil pressure light came on, so I go to stop and it goes out, so I get on the throttle and the light comes on till 4,000rpm then goes out so I let off and the light came on at cruise rpm 2,700. I crusied 30 miles to the next town with no issues and no rattling or anything from the engine. I got to the town and swung into napa and got a new oil pressure sensor and put it in cause the old one was leaking and that's why i kept goin, thought it was just the sender. So I get new one in and same thing. So I called my dad and he came down with an oil pressure gauge and my buddy and I had breakfast while we waited. He decided to come and have mom bring the car so that if there was issues we could just go with her car. So he gets there we put a gauge on it and the pressure jumps to 30 psi at an idle. When you rev it up it rapidly falls down close to 10psi and then very slowly started dropping more. So I shut it off and went and talked to the guy that owns the perkins it was parked at and he said I could leave it there. So we took moms car and I'll get the trailer and haul it back monday. Thing is I've never seen one loose oil pressure when you rev it up, usually it's the other way around. I'm not sure if i hurt the motor by drivin it or if it may have had enough oil to keep things lubricated. I'll pull the pan and check bearings next week and see if I can find a problem. Until then anyone seen this before???? I guess worst comes to worst I'll have to rebuild it.

 

[marc780]

I have a couple guesses: maybe your pressure relief valve in the oil pump is stuck open;
Old and dirty oil filter bypassing the oil away from the filter; oil too thin due to gas or coolant dilution from a very rich condition or an internal leak; slipping timing belt due wear and/or to a weak timing belt tensioner that is not driving the oil pump fast enough.

BTW whats the year and miles on this car? High mileage i'm guessing. The rule of thumb is that an engine needs at least 10 psi of oil pressure for every 1,000 rpm. For example at 3,000 rpm on the freeway you should be getting a bare minimum of 30 psi. On a healthy engine generally its more like 40 or 45. So if you drove it with low oil pressure like this, cross your fingers and hope there wasnt any damage because there may very well be, unfortunately. :sosad: If you didnt hear any noises from the engine you may be in luck though -

 

[toyomoho]

With this low of oil pressure, don’t drive the car until you figure it out. The oil pump and relief valve is accessible from the outside of the engine. There is an oil cooler bypass valve, but not sure this would be an issue (plugged oil cooler?). Also a filter screen on the oil pump intake located within the oil pan.

 

[BLstangin]

Ya guys just to let ya know i'm an ase certified tech and build serious v-8 race motors for people and am personally not to worried bout it. I run valvoline oil and a wix filter and they always have worked good. I am just curious if anyone has seen this cause as pump rpm go up so should pressure, not the opposite so it's really strange. I guess if it blew up i'll rebuild it I just wanna know if anyone has seen this before as it seems odd and anything I learn new can only help. I put a timing belt in it and water pump 1,000 miles ago and also changed the oil at the same time and it looks golden and almost brand new yet. Also oil is full. It has 260,000 miles on it so I guess maybe it's time. Thing is i've only drivin it for 1,000 miles cause I got it for free cause trans was smoked in forward clutch pack, rebuilt it and got all other minor things fixed so it's like damn give a guy a break ya know? But I'll let ya all know when I pull ithe pan and the rod and main caps and inspect bearings and pull the front apart and pull pump. I hope it isn't to bad. I know I was stupid to drive it that way but since the sender was leakin and it was flickering on and off and I know it's a problem on the 5sfe I figured I was fine plus usually youll hear the rods rattle sorta speak with low oil pressure and I didnt' hear it. Plus it was -3 today plus windchill so sittin on the highway for 2 hours waitin for my parents woulda sucked big time, so I decided to chance it. I guess we will see how much harm i did when I get it home. the most it will run is to pull itself on a trailer, then into my garage, maybe a minute run time. Then i'll tear into it. Thanx guys.

 

[GaryS]

I had to chuckle when you said "damn Toyota" and then post that the car has 260000 miles on it AND you got the car for free. :lol: So, may I assume that you are disappointed that your can ONLY got a little past a quarter of a million miles before you started having oil pressure issues?

 

[BLstangin]

HAHA na i know it had 260,000 thou on it when I got it. I just have done tons of work to it so i was hopin it would run a little while anyway. But i'll get it home tomorrow and go from there.