How much is too much? (oil pressure)

[cak]

Now that I've got the electrics sorted enough, I'm driving (yay) my new-to-me 73.5 911t (with what seems to be the original 2.4, about 70k miles). I'm trying to figure out what's what; this is my first Porsche.

One thing I notice is that the oil pressure can get quite high, especially while going up through the gears.

Driving around town, it's in the 20-40 psi range, which doesn't bug me for 2500rpm. But pushing up towards redline with the oil warm (about 180) I see as much as 140 psi (upper end of gauge, but not pinned).

Sometimes while cruising the freeway (3200rpm), I'll see the oil pressure hold around 60 or so, and sometimes it flutters up to 100+.

I don't have any sense for what's "normal" on these cars. Is this? It seems like a pressure relief valve is sticking ... do I care? High oil pressure is wasted power, but I worry more about blowing off a fitting or filter. I'm careful to keep the revs low while the oil is cold.

Thanks.

[Nostril Cheese]

sounds like maybe the sender isnt calibrated to the gauge?

On my Carrera, the gauge would peg to the top before it finally failed.

[cak]

On my Carrera, the gauge would peg to the top before it finally failed.

Um ... what failed, and how? (eek)

[Nostril Cheese]

sorry, the sender on the engine. I pulled it off one day trying to trace down the problem, and upon shaking it, there was something loose inside. I just bought a new one and popped it on. Good as new. I imagine it failed due to age.

On the earlier engines, i believe the sender is on the back of the engine near the transmission. On the later engines, it's on the right of the fan housing, connected to the oil line coming from the cam housing.

[cak]

Ah. Replacing the sender sounds way easier than repairing the relief valve! Thanks. I'll try to find it next time I crawl under the car.

[Nostril Cheese]

the sender isnt under the car. pop the lid and look to the right of the fan housing. You'll see a grenade looking thing connected to an oil line.

at least Im pretty sure its like that on a 2.4.

It might be in the back of the engine on top

[Superman]

With the key on, disconnect the sender. Then touch the wire to ground. One of those things will make the gauge go to zero, and the other will peg it.

[cak]

the sender isnt under the car. pop the lid and look to the right of the fan housing. You'll see a grenade looking thing connected to an oil line.

Hmm. OK, I see a photo on our host's catalog, I know what to look for (yow! pricey!).

i believe the sender is on the back of the engine near the transmission.

Yes. Well. I'm still getting used to calling the space in the front a trunk, and don't really have a good sense of what "front" and "back" regarding the engine mean, relative to the rear bumper.

But "near the transmission" makes me think closer to the front bumper ... is that front or back?

I *do* know where the fan housing is, though!

[dfink]

Rear of engine is where fan is. The tranny is connected to the front.

[Nostril Cheese]

back of engine means towards the front of the car.

the fan is considered the front of the engine

[cak]

[Nostril Cheese]

lol.

I always considered the fan as the front of the engine