3.4 oil pressure question

[dobie]

What should the oil pressure be at idle when the engine is hot?
I have 55psi when cold and it drops to a little below 20 when hot and I'm wondering if that's within spec. I'm using a pressure gage not the dashboard gage.

[nascar24jd]

Re: 3.4 oil pressure question

That is not horrible, but it is a little low. What weight oil are you using?

[Leonard 3.8L]

Re: 3.4 oil pressure question

What should the oil pressure be at idle when the engine is hot?

i would say around 20 psi or so.

[VTJosh]

Re: 3.4 oil pressure question

That sounds alittle low. Mine fluctuates between 40-30 at idle when the engine is warm.

[Leonard 3.8L]

Re: 3.4 oil pressure question

http://www.international-auto.com/fi...ure-gauges.cfm

Potential Causes of Low Oil Pressure:
Low Oil Level - You may first notice your oil pressure dip during a hard corner or under sharp braking. Stop at once and top up the oil, or you can seriously damage your engine!
Diluted or Worn-Out Oil - (see above).
Damaged Oil Pan or Pickup Tube - Have you scraped or banged your oil pan? Stop at once!
High Oil Temperature - Generally not a big factor, but if you're pulling a trailer or running flat out in really hot weather, your oil can run well over 250 degrees F., and oil pressure will be lower.

Worn Engine Bearings - (see above). A further indication can be a heavy knocking under engine load (main bearings) or a lighter knocking (connecting rod bearings).
Worn Oil Pump - This could be anything from a slight reduction all the way to catastrophic failure (which is rare unless the pump has ingested bits of metal from some other failure).

Dropped Crankshaft Plug(s) - This is not terribly uncommon in 4-cylinder Alfa Romeo engines. These metal plugs fill the holes where the factory drilled oil passages in the crankshaft. If one falls out, oil pressure will suddenly drop across the board. You can still drive (slowly) to get home, but the plug(s) will need to be replaced.

[dobie]

Re: 3.4 oil pressure question

i would say around 20 psi or so.

I'm running 10w-30. I just rebuilt the engine and it has less than 50 miles on it. I just changed out the oil and filter and the oil that came out seemed kinda thin. The engine slightly overheated once because a bad temperature sensor didn't turn the rad fan on which is what thinned out the oil. I put in Valvoline Durablend 10w-30 and haven't had a chance to run it since I'm waiting on a new oil pressure sensor. I didn't change out the oil pump when I did the rebuild and I'm hoping its not coming back to haunt me.