1996 2.7L Low oil pressure light at idle!!!

Recently after about a 45 minute drive, coming into town my oil pressure light blinked on at a red light (at idle). And then just above idle it goes back out. Did a few searches and didn't find this exact problem. It seems to have gotten worse as the weather has turned colder. Now tonight the light is staying on until about 1500 rpm and I pulled the oil fill cap off and noticed quite a bit of blow by. Is that normal, haven't noticed it before? The truck has 134,000 miles on it. And I also noticed that when starting it seems like the engine is not turning over as fast. Feeling more and more like I'll be putting along block in it. What do you guys think. Where is the oil pressure sender, I would like to put an actual gauge on it and see what the pressure is.

 

u could need to replace the oil pressure sender. check all seals make sure no leaks.

 

Could be a combination of things. What weight oil are you running? If your oil is too heavy that would account for why it's turning over slow in cold weather. If your motor is idling a little on the low side and your oil is too heavy, you're not getting sufficient flow at idle. That can cause the sending unit to turn on the low pressure light. Also, at 134,000 miles your oil pump could be getting a little weak. I'm not sure but I believe the manual recommends 5W30 for that motor or 10w30 if the ambient temp is above 0F. Anything heavier than that can cause problems in the winter, especially if your oil pump has a little age on it.

 

Most of the time, the oil pressure sensor is the problem.

 

This morning I installed a manual gauge and after a few minutes of idling the gauge shows around 2-3 psi and the light is on at this point. So I feel like the sender is doing it's job. (I put a tee in so I could see what pressure the light comes on at while looking at the gauge. So what now? How much blow by should I have at the oil filler cap? It seems like a lot to me? Maybe not considring the mileage. The engine sure seems to run good and does not use oil at all, it has no leaks anywhere. I'm thinking i should do a compression check on all cylinders, and if they turn out good then maybe I can just replace the oil pump. Oh yeah by the way about the most psi I can ge out of it at about 4000-5000 rpm is around 30 psi.

Could I have a clearance problem in some of the bearings? Like i said I have zero knocking and the truck seems to have good power. What about the cam, is it like a V-8 with pressurized bearing fit or is it just splash lubricated? Thanks for all your help.
John

 

I'm having the same problem with mine. It lost power on the highway, I pushed in the clutch and the engine died. Cranked over very slowly and finally started, but the oil light was on at idle and it's knocking. It's going to the dealer tomorrow.

 

That's exactly what happened to me, I'm just wondering if I can get by with putting an oil pump in or if I need a complete overhaul. Let me know what they say at the dealer.

 

I'll let you know. I hope it doesn't need a new engine, it wouldn't even be worth fixing.

 

The oil light goes on after I drive about 4-5 miles and stays on until I let it cool down. It is not overheating. The light goes off or flickers if I rev the engine a bit. Not sure if it is the oil or the oil pump...I have 156K miles.

 

Any luck figuring out what your problem was my trucks runs fine but oil light comes on after a couple miles and stays on until I then it off and let it cool down plus the motor does not rev out and by that I mean it will not reach the rev limiter when you hold the gas down while the clutch is pushed in. Doesn't overheat and doesn't knock but after I while it does sound like maybe the top end isn't getting proper oil pressure and I have already replaced the oil pump but no changes
Please help!

 

I have the same engine and I can confidently say that no matter what they seem to produce a lot of blow by. Other users and guys on Yotatech can confirm that. Mine sounds like another exhaust (just a lot quieter) when you take off the oil cap while it is running. However, generally the 3rz oil pump is a pretty solid unit so I would change the sender unit first. The oil pump on the 3rz can be changed if worse comes to worst.

 

change the oil and filter more regularly. use high quality oil. no pennzoil. the engine obviously is worn. more than likely the main bearings. maybe use a little heavier oil. you don't have that much cold weather up there.

 

Was there any resolution on this? I'm having exact same problems. About to put it back together with a cleaned bypass valve, cleaned sump screen, and new oil pump. I'm checking my bearing oil clearances tomorrow before it put it back together.

 

These all sound like Main bearing tolerance issue's to me.

 

I'd say you're right. And I hate that you're right.

Main bearing 1



Main bearing 5