Jump to content
Ultimate Subaru Message Board

Oil pressure: How low is too low?


Recommended Posts

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?

Link to comment
Share on other sites

*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.

Link to comment
Share on other sites

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.

Link to comment
Share on other sites

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

loojjjjj.JPG

Link to comment
Share on other sites

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.

Link to comment
Share on other sites

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

No change in the oil pressure. :banghead:

 

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.

Link to comment
Share on other sites

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.

Link to comment
Share on other sites

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..

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...