off the scale oil pressure in late model 550 when warming up

My 2001 550 takes about 10-15 minutes to warm up properly (getting oil temp to the proper point)...this usually consists of about 5 minutes of letting the car sit after start up, and 10 minutes of very easy low RPM driving.

Recently, since my annual fluids service and getting my x-pipe installed, Ive noticed that when the car is in this warm up stage, the oil pressure can get extremely high, easily going to past the max point with even minimal sustained revs in 1st or 2nd gear (were talking anything over 2000 RPM, so nothing excessive by any means.) I find myself constantly eyeing the pressure gauge, and de-clutching when it gets too high...annoying to say the least!
I know that early 550's had high pressure issues, but I thought these were fixed on later models....and furthermore, I don't remeber the car acting like this last season. That being said, once the oil temp is fine, the pressure falls to normal rates, and stays there even during spirited cruising/reving. When warm, it sits at the first mark/line when idling, and never goes beyong the 3/4 line even at full RPM.

Any ideas as to what may be causing this? Any solutions? Im stumped!

I had originally thought the sender may be shot, but then why does it settle down and read properly when the car is warm? I also have it seviced at a Ferrari dealer, so I highly doubt (although I cant say its impossible) that they used a heavier oil by accident.

 

Sender going bad?

 

Same deal on my 2000 550. its due for its annual oil change and I know that some synthetics get thicker, maybe thats the problem

 

As I mentioned in my original post, if it was the sender....why would it start to provide accurate readings after the car was warm?...from the descriptions of faulty sensors I've heard, once they start reading high they read high across the board, not just during warm up.

Also, the oil is brand new, and was put in at the dealership. While I cant completely discount the possibility of a screw up (forgot to replace oil/put wrong oil in) it would seem highly unlikely (or should, considering Ferrari dealer prices! )

Thanks for the input guys, but I think these two are unlikely reasons (unless someone has seen senders acting that specifically weird...)

Any other ideas?

 

If you get an answer, let me know. Mine does the same and has had shims from the pressure relieve valve on the pump removed as a result. Once the engine is up to temp, all is as it should be though.

 

Tight clearance somewhere causing higher pressure until everything warms up and expands?

 

My last 550 did that. It was the sender.

 

At least someone has experienced the same thing.....seems to make the most likely culprit the sender. Weird the way it goes from flakey to accurate, but it is a Ferrari electrical component after all...

Guess I'll have to get it replaced, just seeing those readings makes me nervous, even if they are most likely inaccurate....

Thanks everyone for your input.

 

Maybe not, whilst it is true the seners can give faulty high readings, when cold, with a mechanical gauge I see 90PSI pressure at 2K rpm until the oil has warmed up over 70C.

 

What viscosity oil did you put in? If it's higher viscosity than before it could be causing this problem.

 

The sender on my old F355 almost gave me multiple heart attacks. I had already replaced it after it had suddenly gone to "zero", but since the engine didn't die I suspected that oil pressure was actually still there... Then one day the new sender was working fine, and the next day it would skyrocket all the way off the scale when I started the engine from cold, only to plunge to a too low pressure as it warmed up. I didn't know what to think, until I tapped my finger on the sender gauge... and it sprung back to life, once again showing the right pressure. I think sometimes it's not the sender itself, but actually the electrical connections in the dashboard behind the gauge that oxidise or short out. Try tapping on the glass and see if it comes back...