Changing the oil pressure sensor

[Dave]

Watched my oil pressure gauge "stick" on 5 bars at hot idle and fall to 2.5 bars with the engine off (!) for too long. Either that or it goes to 2.5 bars before I start up or on a good day indicate more realistic pressures and function normally.
I intend to change the sensor, do a "how to" and find/prove an equivalent part. So, instead of having the part in my hand and matching it to the already installed item I've been under the bonnet and think I've identified it. Can someone confirm from my picture that the pressure sensor is the aluminium body, with a spare terminal, hiding underneath the black plug

 

[philw696]

Dave,
I changed mine on my 4200 about £65 from eurospares need to modify a 24mm spanner to remove and refit.
Due to lack of space and my big hands i removed the manifold.
Phil.

 

[SteveM]

Hi Dave, I had same problem a few weeks ago on my 3200 and changed oil sender when the Rad was out. See photo below.

I managed to locate replacement going cheap in the States using original Maserati part number 183452. I was suprised as 3200's not sold in USA but apparently same part number used on earlier V6 model. (Someone else may be able to advise which one)

If you refer to Thread " Radiator, are you aware" Post 20 you can read about an alternative way to get to Oil Pressure Sensor otherwise I believe the more orthodox way is to loosen the timing belt and drop the A/C compressor sufficiently to get a spanner on the Sensor.

Good luck as this is a common problem and happy to report after 2 weeks its rock solid at 5 bar all the time. Steve

 

[Dave]

Thanks for that. It's in a 4200 whether it's the same sensor as a 3200............ don't know.
Probably a Fiat Panda standard part !!
Realised a crows foot spanner was needed but didn't know the size, so thanks for that. I'll get hold of one.

The item I photographed then is the right one ? There isn't much else in that area to confuse with it..

 

[hodroyd]

Meridien £77.70 PN: 183452, or about half that from Eurospares I think. Same on 3200 / 4200

 

[Emtee]

Looks like the right part Dave, but here's the Eurospare's diagram for confirmation. Part 52.

 

[Dave]

Whilst waiting for the replacement to arrive...

...I removed the bits and pieces to access the sender. (If this works there should be an attachment to this entry.)

If it is helpful I'll continue to document the "how to"'........?

Should the opportunity be taken to change the cylinder head oil filter while the manifold is out of the way ?

PS The "how to" won't attach (979kb)................is there a size limit or another way of showing it ?

 

[ZAM400209]

Hey Dave,

I know you were half kidding about the Fiat Panda standard part comment, but incidentally (having fooled around abit with 90's Italian electrics) I can tell you that the Panda would have an oil pressure Switch rather than a Sender, which derives a ground (I think from memory) to indicate with a poor oil-pressure lamp. No pressure instrumentation as such and no Sender to feed it.

If the 3200 is like the Ghibli (I have no knowledge of 3200 engine management) it will have a separate Switch nearby for a similar lamp in addition to the gauge; otherwise, such a lamp must be fed from the ECU which is monitoring the gauge- which seems unlikely...

ANYWAY- a little aside there but I thought I'd drop it in.

JimP

 

[conaero]

PS The "how to" won't attach (979kb)................is there a size limit or another way of showing it ?

It should do, email it to me: admin@sportsmaserati.com and Ill take a look at it for you.

 

[Emtee]

Hey Dave,

I know you were half kidding about the Fiat Panda standard part comment, but incidentally (having fooled around abit with 90's Italian electrics) I can tell you that the Panda would have an oil pressure Switch rather than a Sender, which derives a ground (I think from memory) to indicate with a poor oil-pressure lamp. No pressure instrumentation as such and no Sender to feed it.

If the 3200 is like the Ghibli (I have no knowledge of 3200 engine management) it will have a separate Switch nearby for a similar lamp in addition to the gauge; otherwise, such a lamp must be fed from the ECU which is monitoring the gauge- which seems unlikely...

ANYWAY- a little aside there but I thought I'd drop it in.

JimP

If it's the same as the 4200, it's as you say Jim with the warning lamp fed from a switch separate to the sender, which sends it's signal just to the guage needle. Don't ask me where the switch is. I'll ask next time I'm at Shiltech.

 

[Fat Arnie]

That sender is made by VDO. 5 bar. All you need know is the thread. Does someone have one off a car?

 

[spydercc2002]

There's some useful info at
http://www.maseratilife.com/forums/coupe-spyder-gs/10893-oil-sending-sensor-replacement.html

 

[Dave]

Have sent the draft "How to...." Matt as requested. Thanks for the links.

I will try and identify the original supplier of the sender when I get my hands on it. Might be in the post today.

 

[conaero]

Yep got it Dave and duly replied.

 

[spydercc2002]

That sender is made by VDO. 5 bar. All you need know is the thread. Does someone have one off a car?

By pictures It looks like M10x1 thread, because it have a copper washer sealing. The alternative NPT-thread ones does not require any washer.
http://www.ricambiamerica.com/product_info.php?products_id=197781

 

[Dave]

Sender has arrived........

The sender has an 18mmx1.5 pitch thread, is 0 to 10 bar, 24mm A/F nut and accuracy of 0.75+/- 0.15 bar. I suspect that it is a "special" because of the unusual thread diameter. Parts4aircraft (amongst others) sell the (apparently) same VDO sender with 1/8 NPT thread (part 362-002)and a whole range of adapters to suit. So, a sender is £48 vat inc and an 18mm adapter is less than £10 vat inc. A much cheaper solution. There are equivalent senders available (other than VDO) which are even cheaper. I'll finish the "how to..." and pass it via Matt for anyone to use.

PS I'll run my multimeter on the sender and put some pressure into it and see what the readings are, also rip the case off the old one to see why they stick.

 

[Emtee]

Thanks Dave, Having worked my way through three senders on my previous car, I'll be interested to hear of your findings......

 

[spydercc2002]

The sender has an 18mmx1.5 pitch thread, is 0 to 10 bar, 24mm A/F nut and accuracy of 0.75+/- 0.15 bar. I suspect that it is a "special" because of the unusual thread diameter. Parts4aircraft (amongst others) sell the (apparently) same VDO sender with 1/8 NPT thread (part 362-002)and a whole range of adapters to suit. So, a sender is £48 vat inc and an 18mm adapter is less than £10 vat inc. A much cheaper solution. There are equivalent senders available (other than VDO) which are even cheaper. I'll finish the "how to..." and pass it via Matt for anyone to use.

PS I'll run my multimeter on the sender and put some pressure into it and see what the readings are, also rip the case off the old one to see why they stick.

Thanks Dave. The closest one in design I can find is the VDO 30/70C

 

[Fat Arnie]

Its worth checking the connections on the sender are tight before swapping it out. They are quite prone to vibration on other cars I have had with the same VDO item.

 

[conaero]

Its worth checking the connections on the sender are tight before swapping it out. They are quite prone to vibration on other cars I have had with the same VDO item.

I also found that due to the route of the wiring, they get exposed to heat over the top of the block and hence go crispy. It's worth looking at.