Low Oil Pressure On A 2.7
Posted April 8, 2009 at 04:27 pm
At about 130k, my wife told me the oil light would flicker or come on at idle when the engine was warm, usually when she was stopped and in gear.
I checked my sources and read about the replacement wiring harness for the oil pressure sender, then I read about a replacement for the oil pressure sender.
I replaced the sender with a Genuine Mopar Part from a dealer, but no change.
This last week, I installed an oil pressure gauge and it read 45 lbs at cold idle going as high as 75 lbs at 3000 rpm. But when it warmed up, at 2500 in OD, the gauge needle rested on the pin and the only way to make it rise was to shift back into 3rd. At 3000 rpm, I can get about 5-7 lbs.
I know I have (or had) the correct clearance on the new bearings, I checked them all with plastigage and none of the journals had any scoring (had it been any other engine, I never would’ve replaced any bearings that looked as good as the originals in this engine).
My question now is; Should I have replaced the oil pump? Do these go bad on the 2.7? The engine is still quiet, idles without any noise, no clicks or knocks at all, and runs good. I was certain I had a faulty oil pressure sender and that is why I put a gauge in.
I’m really frustrated with this. Any and all help is greatly appreciated.
Posted April 9, 2009 at 02:47 am
I would much more suspect a widening of tolerences or relief valve/spring failure or even the oil pickup tube-to-pump o-ring failing.
I'd drain the oil and drop the pan for a look-see. Hopefully minor.
Posted April 9, 2009 at 08:19 am
I replaced the pickup tube O ring when I had the engine apart. I suppose I should have replaced the spring instead of shimming it, or maybe the whole pump. I have had others tell me that these oil pumps never fail, that it is always a bearing issue. I just didn't want to pull the engine again, and if that is what it comes to, I think I'll look for a 3.2 or 3.5. I have a wrecked 93' Eagle with a 3.5 that I was going to swap for the 3.3 into a 93' Concord I used to have but never got to it. I was told that the 93' 3.5 would not be worth the effort to try to swap into an 01'.