Hi my 91' Accord with 173,000 miles looses oil pressure when engine is hot. Im using cheap parts plus oil right now. Would it be worth it to use amsoil or a better brand like that.

Does the better brands hold viscosity with heat?

 

I doubt the oil is your problem, my friend. Are you burning oil?

Also, what weight are you using?

 

no its not burning or leaking any oil or other fluids.

As of right now im using 5w30 as with some Gunk oil treatment.

 

that is normal, what hot pressures are you seeing?

 

Some high mileage oils will leak less, but if it's not leaking, the type of oil won't matter. Are you sure you're not burning it? Any odd smoke from the exhaust or under the hood?

 

It's not that they leak less, it's that they swell up the rubber gaskets in an effort to mitigate some leaking. The oil itself isn't magical and leak less.

Provided your oil is the correct weight (5w30 IIRC) and you have the correct sized filter (M104 if Mobil 1) then you should be ok on those items.

Are you seeing a Check Engine Light (CEL) ? When you 'lose pressure' or how are you identifying/verifying that's the issue.

 

Well when I was running just 5w30 I had maybe 3psi, but when I added the gunk oil treatment it raised it to about 8psi.

Heres my psi readings:

Cold Start Up: 80-90psi
Warm idle: 25psi
Hot Idle: 8psi

With the oil treatment it raised the viscosity to 10w40

The gauge im using says:

Engineered as Class B (3-2-3)
0% - 25% span = 3% accuracy
25% - 75% span = 2% accuracy
75% - 100% span = 3% accuracy

 

the guide line that I was told is you want 10psi for every 1,000rpm, so if you are stock idle speed ~750-850rpm then even 8psi is ok. Is sounds like you may have a worn oil pump or worn bearings that are allowing the pressure to drop.

 

alright ya when I hold my idle at 1000 it goes up to close to 15psi

 

An oil pump does not create pressure, it simply moves volume, what creates pressure are all the bearing clearances and seals.

Also oils are all pretty much the same regardless of brand, as long as they are ASE, API, and ILSAC rated. If you want you can try running a thicker weight oil because these oil will create more pressure flowing through looser clearances.

 

like i said in the other thread, you're ok then