Just noticed this on the way home after a really bad day and this didnt help it any. Under 2000rpms my oil pressure went to 25 or under in some instances. If i kept it at around 2800 or 3k it would stay at 50psi. Im not used to seeing 25psi at anything other than idle let alone anything under 25 period. Does this sound like a crapped out oil pump or a faulty sender? Does anyone have a picture of a worn out oil pump on the inside? I took this pump out and resealed it and everything looked nice to me but maybe i was mistaken.

 

I might also want to add that when i first put in this motor it was showing insane oil pressure (as in 75 cruising around warm). That makes me think maybe sender.

 

assuming these pumps have bypass valves? Could it be sticking/going out on me?

Edited September 1, 201015 yr by hatchsub

Are you sure it's not just the gauge? The ones in my EA81 wagon are quite inaccurate, and in fact read higher with the headlights on. Perhaps test the pressure with a real gauge and/or put an aftermarket one in and go from there.

Could be but until i find out for sure im not driving it. That was way low and this is a "new" motor for me so i dont really feel like burning out main bearings.

Borrow or buy a mechanical gauge. I refused to drive my hatch that way on mine wouldn't read anything at all but I had no tick. So 2 senders later and 1 replaced pump I finally bought a 16 dollar gauge @ autozone which worked like a charm after finding the right adapter in the back because the adapter kit that comes with the hose DOES NOT! HAVE THE CORRECT FITTING. I will post a part number when I find the bag it came in and saved it just for purposes like this.

 

Mike

As far as the 'high' oil pressure, it could very well be correct. I've tested mine with my mechanical gauge, and on cold start up and high rpm cruise, I'm pushing 70psi. You do need to see if there's a lower pressure issue just to be safe. Rule of thumb is a minimum of 7psi per 1000 rpm before engine damage PROVIDING you are not pounding on the engine. Mine idles at around 35psi.

I don't think those numbers are that bad at all. I believe you may have had a blocked passage or sending unit previous to the rebuild and the new pressure seems to be what I remember specs being for an ea81.

 

Correction....

 

83 FSM says:

500 RPM...50 psi assuming 167-185 degree engine oil.

2500 rpm 57 psi

 

I assume you are using a factory oil filter? It does mess with the bypass valve.

 

Also, the oil relief valve could be sticking I assume you went thru the oil pump and cleaned and resealed it during the rebuild...but I have seen 2 guys that didn't. I believe this is the spring with the ball on the end of it in the oil pump itself.

I didnt in fact open the oil pump up. it has 52k on it and i didnt want to pop it open since i didnt have new gaskets to put it back together with and it was a matter of time that i wanted the car back together in a timely manner. I also did not do a full rebuild...just a top end. I didnt split the case.

Check your readings with either a shop gauge or a decent aftermarket oil pressure gauge.

 

You should open up the pump for sure - mileage has less to do with it than maintenance. I've seen some ugly stuff inside them. The seal kit is like $8 from the dealer and a new pump is about $65.

 

You get my PM?

 

GD

You get my PM?

 

GD

 

The one about fuel filters and a higher flow fuel pump? Yup i got it and actually ordered new fuel filters from rockauto the same day lol.

 

As for the oil pressure...i swapped sending units with my other motor. I also noticed the monster oil leak that had been coming from the sending unit. So....resealed and "new" sending unit and all is well. 57psi hot cruising and 25psi hot idle. Figure im in the clear as far as oil pressure goes. This is the motor that was spotless on the inside so i dont really think im going to bother pulling the pump apart at this point. Maybe if i get some free time but it seems to be just fine. Oh and im running mobile 1 in it now. Maybe overkill but i saw what the inside of the other one looked like. I dont really feel like seeing that again.

25psi hot idle is good. That's what I like to see - no less than 20 IMO. I keep two spare OEM oil pumps on the shelf for my EA81's. Just because I'm paranoid about them.

 

GD