Just installed a mechanical oil pressure gauge in my ea81t. I've done a search on this, but didn't come up with what i wanted.

 

Once the oil is up to temp, it sits at around 10psi at idle, and around 35psi at 2500rpm.

I know this is lower than the specified pressure, but does anyone know if its too low for the hydraulic lifters to function?

yes you will notice some TOD from that low of oil pressure.. if it does, try some 15w-40

The general rule that I have heard from a lot of reliable sources is around 10psi per 1000 rpm. Although your oil pressure is not stellar, I don't think it's low enough to cause problems.

If it was N/A I'd say it would be fine, but since its a turbo they get ran harder and they run hotter. I'd want at least 20psi at an idle and probably 45 or 50 at 2500.

Thanks guys.

i have a spare oil pump sitting around, so i might give that a check and put it on. Better safe than sorry, ay.

*hijack*Hi Ross,

How/where do you use/get an oil pressure tester? Does it sit under the bonnet, or do you attach/detach it when you want to take a reading?

*/hijack* ... apologies for the hijacking.

dont trust mechanical gauges, just because they are new. mine is 10 lbs off.

 

it takes 4 lbs of pressure to pump up lifters. if you arent ticking like mad, your pressure is fine.

*hijack*Hi Ross,

How/where do you use/get an oil pressure tester? Does it sit under the bonnet, or do you attach/detach it when you want to take a reading?

*/hijack* ... apologies for the hijacking.

 

No worries..

 

Buy them at any auto parts store. If you get a mechanical one, tey come with gauge, hose, and fittings.

These fittings fit into where your factory oil pressure sender/oil pressure switch goes into (on oil pump on ea81s).

There is also a spare port that you can use on the ea81 oil pump so you can keep your oil light and turbo line (if its a turbo).

You then mount the gauge in your car.

if you arent ticking like mad, your pressure is fine.

 

It is ticking like mad. Im gonna swap in a good oil pump today, just to rule that out before i start getting more drastic, or decide to just ignore the ticking.

A more worrying noise i'd like to remove is a faint knocking at idle. Im hoping a little more oil pressure will fix it.

No worries..

 

Buy them at any auto parts store. If you get a mechanical one, tey come with gauge, hose, and fittings.

These fittings fit into where your factory oil pressure sender/oil pressure switch goes into (on oil pump on ea81s).

There is also a spare port that you can use on the ea81 oil pump so you can keep your oil light and turbo line (if its a turbo).

You then mount the gauge in your car.

 

they look like this

Some more info on the problem:

Running 10w40 mobil synthetic oil + subaru filter.

Oil pressure 70psi at 2000rpm with engine cold.

Drops to 8-10psi @ idle, 30-35psi @ 2500rpm.

Develops TOD and light knock when idling when engine fully warmed up.

 

My other oil pump is no good, so the other option is to buy a new one for NZ$120. (I'd prefer to be able to do a quick swap ratehr than take the other one off and re seal it, especially if its beyond repair.)

 

Any more opinions on whether this oil pressure is too low/whether i should get the new pump?

 

Cheers.

bad oil pressure can wear the cam and crank bearings making the problem even worse.

 

id like to see at least 1 bar at idle. if you get the new oil pump you at least get the peace of mind that its no longer a problem.

Well, got the new oil pump and put it on yesturday.

No change in the oil pressure.

 

The old pump looked like it had been replaced resonably recently. Thats ok though, at least i have a good one for my other ea81.

 

So, im thinking it must be worn bearings.

Is there something else that could be causing this?

 

Its around 5-15 deg. celcius here at the moment, so i dont think my 10w40 is too thin or anything.

Anyone think I should check the oil strainer?

 

There is a lot of grime in this engine, so it may be blocked.

Oh dear...... just took the wagon for the first long drive since i put the oil pressure gauge on..... after a while the pressure was sitting below 20psi at 2500-3000rpm.

I think i might want to stop driving it till i get this sorted.

Oh dear...... just took the wagon for the first long drive since i put the oil pressure gauge on..... after a while the pressure was sitting below 20psi at 2500-3000rpm.

I think i might want to stop driving it till i get this sorted.

 

ya, below 20 @2500-3000 is rather low.. Snowman was right when he said at least 10 per 1000 rpm...my EA82 idles at about 5-10 @ idle, but runs 30-35 @3000rpm when warm..