For some reason, when the car is cold, the oil pressure gauges goes to like 40-50 and stays there until it warms up then it drops to 10-20 or so. And the other thing it does is that the throttle sticks a little, it likes to hold a 1500-2000 rpm idle when the car is moving (while in neutral) but if i stop it goes down to the usual 1000. does anyone know why these things happen other than the fact its a 10 year old car?

 

The PCM increases the idle speed when the car is moving. 2000rpm seems a little high, but then so does 1000rpm at stand still. Stock programming for the M6 is 800rpm fully warmed up. The 100-200rpm error of the stock tach could account for your 1000rpm reading. The PCM also sets a higher idle speed, based on low coolant temperature.

What viscosity oil are you using? Looks like it really thickens up a lot when cold.

 

10w-30 regular

 

I'm running into the same oil issue with my motor, Im using 10-30 valvoline..

 

so 1k idle is a bit high?

 

Try dabbing a little oil on the throttle body butterfly rod where the rod enters the body. This cured an rpm hang I had after cleaning the TB. It's normal for oil pressure to be higher when the oil is cold. Oil also warms up a lot slower than coolant. I have an oil temp gauge and it's usually takes about 15 minutes of driving before my oil temp reaches 180 F, whereas my coolant temp is there in about 3 - 5 minutes.

 

Same here with the oil pressure and I'm running 10-30 also. The oil pressure has run high when cold since I bought the car 3 years ago, before and after mods at 54k. It runs high well after the engine heats up in stop go traffic. As far as I can tell it's normal . Sticky pressure sensor anyone??

 

yeah i was sort of thinking that the pressure sensor might be having some issues

 

Oil pressure is higher in all engines when they are cold. The oil is thicker and harder to pump.

 

at idle when warm, the oil pressure is at 10 psi, at 2k its around 40 psi

 

While pressure could be higher, that is not unusually abnormal for an LT1. Sometimes the age of the oil pressure sensor contributes to lower than actual readings.

 

i just checked it over, its 20 psi warm during idle

 

Nothing wrong with that.

 

20psi sound dead on