10psi down

[SlvrCrb]

Went for a run out and noticed toward the end the oil pressure had dropped by 10psi from normal and then when I stopped in traffic the hot idle had dropped by 10 as well. Let her cool down and now the cold idle is 10 down from normal too.

Before:
Cold Ile 42psi
Normal run : 40psi
Hot Idle 22-25psi

Now
Cold Idle 32psi
Normal Run: 30psi
Hot Idle 12-15psi

It's the hot idle that's really bothering me, but could it be something more simple like the sender to the guage?? IS there any other way of checking the oil pressure?

Everything else is normal, oil level, coolant level & temps (85-100), fans are cutting in and out. No MIL light, engine sounds normal. No smoking from the exhaust. Could it be the oil getting too hot? Any insights would be useful before i get on the phone on Monday.


>> Edited by SlvrCrb on Saturday 25th June 16:07

[jesfirth]

Hi John,
Cant shed light on the sudden drop but if its any help i've just checked my oil pressure

70 cold idle
35 hot idle

Have you changed the pressure spring lately? apparently they can fail and cause problems

I've been told by Topcats to use thicker oil for sprinting track days etc They recommended 15/40 semi-synthetic which apparently doesnt thin as much when hot.

hope all is ok

probably see you at APM this week by the sounds of it!

cheers

Jes

[SlvrCrb]

Thanks Jes, although I think you are confusing me with some else (Rob not John)

I haven't checked/changed to oil pressure relief spring yet, so maybe that's the best place to start. I assume it's a 2-3 quid part from a dealer? Anyone know of a 4 post near to brighton I could borrow to get under and change it?

[ceejay]

I had this on my previous 4.5, exactly the same symptoms and similar pressures. Took the oil pressure relief spring out and found it had a crack in it and was about to fail completely. Hope it's this cos real easy and cheap to fix. After fitting the spring I was running at about 70psi.

Ceejay

[SlvrCrb]

ceejay said:

I had this on my previous 4.5, exactly the same symptoms and similar pressures. Took the oil pressure relief spring out and found it had a crack in it and was about to fail completely. Hope it's this cos real easy and cheap to fix. After fitting the spring I was running at about 70psi. Ceejay

Cheers ceejay, make me feel better now just need to work out how I'm going to fit it, as I don't have under-car access in my garage and I assume I shouldn't be driving it anywhere till it's fixed.

[vinny73]

I noticed my pressure is 10-20psi higher now after a service and a new spring :-)

[Chuggaboom]

That does sound a bit low....round Combe yesterday I had oil pressure in the high 60's and and water temp in the low 70's according to the Stack digital display....about right I'm told.

G.