85 GL hatchback

with 138,000 miles

the oil pressure is steady at 75 which is max'd out

is this normal, what is the proper pressure

it falls when i release the throttle and climbs right back up????

85 GL hatchback

with 138,000 miles

the oil pressure is steady at 75 which is max'd out

is this normal,

No this is not normal all the time.. first when started yes but should fall to middle or about 25/30 pounds. what is the proper pressure

it falls when i release the throttle and climbs right back up????

 

How long since the oil filter changed?

Possibly sending unit is bad.. Located on Oil pump, fed by a single wire. Sure there is a way to test it but not sure, check chilton's etc..

condition of normal, but.... are you using something like 20-50 oil??? I know its vermont, your car should be thawed out by now... These gauges are not what you would call "spot-on" they are more/less and indicator of rise and fall of the peticular system being monitored.

 

make sure to run between 10-30 and at the most 15-40 weight oil.

 

there are many opinions on this, use what is defined in your owners book or tech manual for the given atmospheric temperature encountered.

 

either way, do you really want less oil pressure?

 

Lewis

1. Does the gauge fall to exactly zero when powered off? It should. If it doesn't the gauge itself is adjustable but it requires dissasembly of the cluster.

 

2. Does the pressure decrease once the engine is warmed? It should.

 

3. Test the pressure with a known good mechanical gauge. Otherwise you are just guessing.

 

4. You should be looking to see higher than 20 psi when the engine is at temp and idling.

 

5. Look for it to climb to 40 or 50 psi at cruiseing RPM.

 

6. You should never see 75 unless something is very wrong or your gauge/sender is fubar.

 

GD

1. yes

2. no the pressure gradually climbs to 60-65 then once on the go, it stays at 75 only falling when throttle release

maybe the gauge is just of by 30-40 psi

but its not falling once warm???

thanks General i will purchase a good gauge

where is the oil pressure sending unit???

 

make sure to run between 10-30 and at the most 15-40 weight oil.

 

there are many opinions on this, use what is defined in your owners book or tech manual for the given atmospheric temperature encountered.

 

 

Lewis

i am running 10-30 right now, is this ok and what should i run for the winter

thanks again please be patient with me, i am new to these older cars but am much more satisfied with this car than any other:)

10-30 is best year round. If it gets very cold you should invest in a block heater. I would not go to a 20w till it was below 20 degrees and only if I didn't have a block heater. The tollerances in these engines, even after hundreds of thousands of miles, are VERY tight. Heavier weight oil is never needed as the engine will simply destroy itself if the tollereances get that high.

 

Sounds like you have a bad sending unit to me. The sending unit hangs down about 1" to the passenger side of the oil filter. You can't miss it - it's bulbous thing hanging down with a wire attached to it. It's a metric thread somewhere around 12mm or 13mm IIRC. Anyway you need an adaptor for most gauges. Good gauges will come with them, but any pressure gauge that reads from say 0 to 60 or even 0 to 100 will work. Just plumb it in using some nylon tubing.

 

In leiu of buying a new sending unit, you could do this:

 

http://www.ultimatesubaru.org/forum/showthread.php?t=55186

 

That's my poor-man's approach. Then you use a cheap pressure gauge and some tubing.

 

GD

10-30 is best year round. If it gets very cold you should invest in a block heater. I would not go to a 20w till it was below 20 degrees and only if I didn't have a block heater.

GD

GD-

You meant to say don't go to a 20w until or unless it's really HOT out right?

GD-

You meant to say don't go to a 20w until or unless it's really HOT out right?

 

Well no - you use a lighter weight oil so it flows better in low temps. If it's super duper cold outside and the engine has trouble maintaining operating temps then you have to go with a lighter weight oil to compensate.

 

Oh - by 20w I mean SAE 20 weight, not 20 Winter. Sorry about the confusion. Sorry - forgot my multi-viscosity jargon for a second there. Most of the oil I work with is just SAE grade, not multi-visco' stuff.

 

GD