Oil Pressure system.

[Emtee]

Well this seems to be grumbling on.......

Took her to London today and had oil pressure warnings at idle.

Sometimes the dash warning was accompanied by the pressure needle falling below 1 bar on the dial (with warning lamp), sometimes the dial would stay (or stick) above 2.5 bar (about what it should be at idle), but would still throw the dash warning and dial warning lamps (both of which I trust more than the dial). Under throttle the dial was correctly up at 5 bar.

Oil is new and checked and at the top end of the dip stick.
I've had her pressure tested (all okay) and have replaced the transmitter (which has got rid of the spiking I had previously)
She's been oil flushed twice.

So this is all directing me to a sticky / faulty / failing pressure relief valve / spring?

Any thoughts? Anyone else experienced this?

Thanks in advance, Em.

 

[deano]

from what you say it could possibly be a sticking prv,as you have used a flushing oil,which could potentially disslodge sludge and get vaught between prv valve and body.i know mdern oils are good at cleaning and suspending contaminants but i have still seen this build up.

 

[2b1ask1]

No experience with Maserati but failure to respond to oil pressure warnings cost me an engine rebuild in my old Merc 123 as the sludge trap was full and caused a blockage on the crank!!!

I've spent the last 8 years paranoid about pressure in anything I drive...

 

[deano]

be advisable to fit a wet gauge to it,and get an actual reading,to satisfy your on mind,before going to far into it

 

[Emtee]

Big thanks for your swift and detailed replies Deano and 2b1. Deano I like your thinking. Though flushed twice she's over 70K now, and was quite tappety beforehand, which was what directed me to thinking she was clogged. Maybe the flushes haven't cleared it all?

Have you come across a PRV failure through general wear and tear?

Will pop into Shiltech tomorrow and get their thoughts.

Regards to both, Em.

 

[deano]

i deal in prototype engines and the build of the 177 aston,so not a maserati specialist,though all are the same principle,and have seen wear on prv's and seen them stuck through carbon dislodged by the oil.get a wet check done,and the tapping noise ide need to hear it to say,would not like to comment on that without hearing it

 

[Emtee]

Thanks Deano. The tapping was something (now all but gone) that I started to fixate on, hence the flushes, though it actually wasn't that bad, as it was only noticeable at cold idle. It would last about a minute (or less) and once the oil was flowing would disappear.

Following my own internal logic I'm happy that the pump itself is functioning (but perhaps under duress from build-up), but that it's the pressure relief system that's ultimately at fault.

Will get a wet check. Thanks for the pointer.

Anyway, on to more exciting things...... YOU WORK ON THE 1:77? Would love to hear more. It's my lottery car (if any of those lucky enough to be on the list decide to sell)

Em.

 

[Dave]

oil pressure sender

Did you get to keep the old sender....I'd like to check it out and see whether I can find a non Maserati equivalent and make up a special spanner to fit it.

There is a small oil filter in the head which feeds the cams and pressure sender - according to the manual. Could this be disrupting flow/pressure ?

 

[Emtee]

Thanks for your comments Dave. I didn't think to keep the sender, but will ask Geoff whether he still has it knocking about. Thanks also for the pointer on the oil filter(s). I think there are two? One on each side. From speaking to Geoff today he does think it's a sticking PRV, but he's going to check the whole system to be certain.

 

[deano]

the 2 filters you mention to me sounds like the filters for the v v t units,these always have a very fine filter as they are very sensitive to contamination,and oil flow,hence why they have there own filtration system.

 

[Emtee]

Part 30 Deano?

 

[Dave]

Thanks for your comments Dave. I didn't think to keep the sender, but will ask Geoff whether he still has it knocking about. Thanks also for the pointer on the oil filter(s). I think there are two? One on each side. From speaking to Geoff today he does think it's a sticking PRV, but he's going to check the whole system to be certain.

Thanks for that, I'm curious as mine has intermittent low pressure indication and silly high pressure - without the engine running.
I'd be happy to source an equivalent and believe that a crows foot type spanner is needed because of limited access.
I'd put some pressure into it and see what the output is (in volts) if it works that way....may even be a plunger/diaphragm type

Thanks again.......

 

[conaero]

Mine did this on my GS, had the sender replaced, and that fixed it.

All I will say, having had endfloat on my 3200, is if the needle flicks, its an electrical, sender or gauge fault, if it moves gradually, it more likely to be a correct reading and indicating a problem.