Oil pressure/temperature sensors/switches

[mangocrazy]

As part of my Spider 2000 engine refurb, I'm now starting to look at the oil filter block and the various senders/switches that connect there. Looking at the S2 parts book there are 3 such items that are listed. These are:

Part Number   Item description
4151997       Oil pressure sender
82240626      Oil temperature sender (Berlina only)
4249594       Oil pressure switch


In particular I was wondering why only the Berlina got oil temperature notification (assuming the parts book is correct), and if anyone has plumbed in an oil temp sender and gauge. I'm intending to replace the 40 year old sender and switch with new items (all seem to be readily available). I realise that the standard instrumentation is only 'indicative' shall we say, and slow to respond, but while I would like to upgrade to more accurate instrumentation I'm not really sure what I would replace the standard kit with, and would prefer to keep the dash as standard as possible.

I'm bracing myself for Eric's response   , but in my defence my requirements are far more mundane than those for a 300+bhp unit.

[peteracs]

Hi Graham

I think you have an oil temp sensor which goes to the top right instrument on the display?

Peter

[mangocrazy]

Hi Graham

I think you have an oil temp sensor which goes to the top right instrument on the display?

Peter

Hi Peter,

It's been so long since I've had a good look at the dash that I've forgotten, to be honest. If so, that's good news and I'll renew all three oil-related senders/swiches. I was only going on what the parts book said for these items. It did seem odd that only the Berlina was blessed with an oil temp sensor/gauge.

Graham

[WestonE]

Hi Graham

Brace brace brace! Actually just get new OE Oil Temp Oil Pressure because the vague slow information they provide is comforting and better than gauges showing nothing. Just not much if you want any accuracy or speed of information.
For the oil pressure switch get an adjustable one or one that is set at 30PSI. The factory one is at 15PSI. This change means the light will come on hot engine no load so you know it works and immediately go out with revs. If it comes on using the car under load you get a few engine saving seconds to hit the clutch and turn off the engine.

If you can find a way to add an accurate Oil Pressure / Water Temp gauge do it so you have more time and information to catch a developing problem. 
You will be shocked at how slow and in accurate the OE gauges are.

Eric   

[mangocrazy]

Hi Eric,

Thanks for the info - much appreciated. I like the advice to raise the threshold for the oil warning light to come on to 30psi. That way you know that if you see it in normal running, it's a genuine problem and needs immediate attention.

Once the engine is back in the car and in use I will certainly look at getting accurate oil pressure & water temp gauges installed that fit in with the OE dashboard layout. Are low profile digital readout gauges available?

Graham

[WestonE]

Hi Graham

If you have an ECU putting out CAN you have a world of digital display options. For example I use a Toucan display. However for most turning the Stereo into a bluetooth receiver/amplifier or moving it to the lower console allows a line of 3 gauges. Racetech Mechanical or Stack Electrical  are my suggestions for quality and accuracy. Autometer offer some nice alternatives away from silver and white which would look wrong in most Betas.

Eric   

[mangocrazy]

Hi Eric,

I've just purchased a 30psi oil pressure switch and 1/8" NPT/M14 x 1.5 adaptor from Competition supplies and while on their site was checking out their gauges. The ones you mentioned were the ones that seemed most suitable for my requirements. I hadn't thought of the CD/radio slot as an option, but that could work well. Definitely food for thought. So with 3 small gauges I could accurately monitor oil pressure, and water and oil temperature. Hmmmm....

What do you do with the OE gauges on the dash? Are they connected or just left to give zero readings? Can a sender support 2 outputs; i.e. one to the dash, the other to an aftermarket gauge?

Graham

[Ferrit]

Evening Graham, did you ever do this?  I am thinking the same after a thought from Alan

My question is can you have the original gauges and the accurate one working at the same time?

[Nigel]

Mark,
To operate both you'd generally have a sender for each, mounted on a T piece.
Especially regarding oil pressure, you'd want a totally independent reading.

N.

[peteracs]

Hi

I agree with Nigel, little point trying to use one sensor for both, just use the correct sensor for each display. Eric suggested to me to replace the over temp switch in the head with a secondary sensor if you want to use one for ECU or secondary temp gauge.

Peter

[Ferrit]

I am going to look at this properly.  Last weekend sat in traffic in Henley for ages I watched the coolant temp climbing and the oil pressure at tick-over slowly looking much lower.  Stressed is a word

So I was going to get a Racetech one, but electronic or mechanical?  I am seeing max pressure of 5.9bar/85psi @ 85dc, so thinking a 100psi gauge would be an easy read?

[peteracs]

Hi Mark

Are you sure the fan is kicking in correctly? You should see the gauge rise then fall a little when the fan kicks in. Obviously performance of the water pump and radiator make a difference. Also make sure your alternator/pump belt is tensioned ok. As the temp of the oil rises then the pressure at idle will drop. Cannot remember what grade oil you used but I changed to 10W50 to solve low pressure when hot, you could also go to 60.

Peter

[lancialulu]

I am going to look at this properly.  Last weekend sat in traffic in Henley for ages I watched the coolant temp climbing and the oil pressure at tick-over slowly looking much lower.  Stressed is a word

So I was going to get a Racetech one, but electronic or mechanical?  I am seeing max pressure of 5.9bar/85psi @ 85dc, so thinking a 100psi gauge would be an easy read?

Got to allow for cold start over pressure on above tick over revs.....

[SanRemo78]

Check the fan is actually working and bypass the thermostat switch on the radiator with a manual one on the dash. You can anticipate when you'll need the fan running quicker than the car will. You may also find that blipping the throttle occasionally will encourage flow around the engine and through the radiator matrix and drop the temperatures quicker. And if you get desperate, drop the windows, open the roof and turn on the heater and fan to max....

[Nigel]

Check the fan is actually working and bypass the thermostat switch on the radiator with a manual one on the dash. You can anticipate when you'll need the fan running quicker than the car will. You may also find that blipping the throttle occasionally will encourage flow around the engine and through the radiator matrix and drop the temperatures quicker. And if you get desperate, drop the windows, open the roof and turn on the heater and fan to max....

As Guy says, but don't 'bypass',i.e. keep the thermostatic switch in circuit, just add a switch
so you have additional manual control.
( I'm sure Guy meant that)

The temp range of that thermo switch is important too. It needs to trigger after the thermostat
has opened but before the rating on the coolant cap.
 
Also relevant: the mod to heater flow pipework at Cyl 4 can help improve circulation. On
original factory plumbing, turning off the heater restricts flow through that spigot.

Edit to add that I now have a 2nd fan mounted in front of the rad on a manual switch.

Nigel

[peteracs]

I realise I also did not add that a stuck half open thermostat will not help the situation.....

Just another thing to consider

Peter

[Ferrit]

I guess the best way to test is to boil them up :-)

I would add a switch to the relay to over-ride I guess

So capillary oil pressure gauges are best for oil pressure?

[WestonE]

Good quality Capillary are most reliable and accurate. Also great for testing a used engine spun on a starter. But it can be a pain to install them away from Race car use. Good quality electrical with gauge and sender matched will be soo much more accurate and faster responding than the OE items. Remember though if you can not see the gauges/gauges it is pointless. If you look at the Montecarlo Turbo race car the biggest thing on the entire dash is the huge low oil pressure warning light right in front of the driver.