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Oil pressure: How low is too low?


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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?

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*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.

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  555Ron said:
*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.

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  archemitis said:
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.

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  Ross said:
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

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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.

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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.

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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.

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  Ross said:
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..

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