Oil Pressure Gauge Gremlins

Paul,
Give Merlin motor sports a ring.
They have lots of adaptors to tee of etc for oil pressure and temp senders.
Not ideal but may solve your woes.
Dave

Hi Dave,

Thanks, that did cross my mind and I was looking at some last night but failed to find one for metric threaded sensors/senders! I'm sure they exist though, and there is no reason why they shouldn't work as far as I can see. Maybe I could fit the earlier two contact sender - that would make life easier! I'll try Merlin as you suggest.

Paul

[quote="JohnC"]
Just for reference, I have just put a meter between the sensors connector and earth without the engine running, and I get a reading of 57 ohms (wiring still connected)
[quote]

Hello again John,

I got a similar, albeit quite variable reading! What I mean is that it ranged from about 35 ohms, to mid-sixties, but predominantly read in the upper forties and into the fifties. Don't know why the reading was so unstable, but it just wouldn't settle. I don't really know what that is telling me - but you can surely tell that I'm no electronics engineer

The spigot on the new sender looks like it is immovable, so I guess that the spigots are unlikely therefore to be interchangeable. You will see Dave Miles suggestion to use an adapter which sounds sensible unless you know different. I couldn't find any metric adapters when I looked on line last night (just npt standard) but someone must sell them. I am assuming that the GTA senders all have metric threads of course. The adapters seem quite cheap - around £7 (all brass).

One further thought - is there any reason why the two-contact sender could not be fitted - that would negate the need for a 'long neck' spigot and the linking block for the separate oil pressure switch sender? Clearly Renault saw fit to switch from the single sender to separate senders for gauge and red light switch for the later GTAs and the A610, but I don't hear of many folks having problems with the earlier two-contact sender - do you?

Paul

I then held a brass rod against the sender (just under the soldered contact point) and tapped gently with a hammer. When I went back to look at the gauge it had moved to about 4 or 5 mm above the centre point of the scale. However, on switch off it dropped only to the central point. Now when I switch the ignition on the needle rises to just below the centre!

Paul ..... can you clarify this please.
You say "However, on switch off it dropped only to the central point." ...... The problem I find with this is that once you switch off,..... the power is removed from the oil gauge circuit, and therefore I cannot see why the meter drops only to the "central point".... it should and must drop to zero.
Then you go on to say "Now when I switch the ignition on the needle rises to just below the centre!" ..... Again, clarity required, At what stage did the meter drop to zero so that it could rise to " just below the centre!". ?
Sorry to be pedantic about this, but one can only suggest things to check, on the info supplied.

You could do a electrical circuit test of the wiring and meter itself,...... with the ign on, touch the wire that attaches to the sensor to earth, and the meters needle should go full scale. This is best done with two people as it is not a good idea to leave it connected as there is no resistance in circuit, and over heating of the meter itself could occure . However a quick touch of the wire will cause no damage at all.

One further thought - is there any reason why the two-contact sender could not be fitted - that would negate the need for a 'long neck' spigot and the linking block for the separate oil pressure switch sender?

That question should be directed to Renault. .................. But if I were building a car, I would not fit the older type sensor with both the Oil Light Warning, and the Oil Pressure Gauge in one unit.
If the unit were to go faulty, the gauge could stop working and the Light could come on. The only thing you could do is stop, and have the car recovered for inspection. However, with two separate circuits you could make a judgement as to whether it is safe to drive home ..... like you found in your Alp recently.
Clearly, If the gauge stops working and the light stays off, you could drive carefully watching the light. Secondly, if the light comes on, but the oil gauge is still registering, again I would be happy to drive on carefully.

John

PS, It appears that Simon Auto's has the sensor and judging from the price, it is the correct one ...... Euro 135.66 ...... Pt No. 011122

Paul ..... can you clarify this please.
You say "However, on switch off it dropped only to the central point." ...... The problem I find with this is that once you switch off,..... the power is removed from the oil gauge circuit, and therefore I cannot see why the meter drops only to the "central point".... it should and must drop to zero.
Then you go on to say "Now when I switch the ignition on the needle rises to just below the centre!" ..... Again, clarity required, At what stage did the meter drop to zero so that it could rise to " just below the centre!". ?
Sorry to be pedantic about this, but one can only suggest things to check, on the info supplied.

John,

When I switch the ignition on, the needle rises to a fraction under the gauge centre (initially on switching the ignition on the needle rose to just the right hand end of the left hand orange band). On starting the engine, the needle moves just a fraction further, but does not respond to varying engine speeds. Of course when I switch the ignition off completely, the needle returns to zero (fully left). Sorry to be unclear - when I said switch off I meant the engine, not the ignition circuit.

Paul

Paul, you should receive a PM from me.

John

Ambiguity sorted .... Thanks Paul.

As a matter of interest, I checked the other day on Simon Auto's site for availability of the OE part ... No. 011122, and the price was given as Euro 135.66. This morning, I have just checked again to check availability, and there is no price, and it says "Ask Price". So it does look as if they are now out of stock.
I did suggest to Paul that if I had his problem, I would not hesitate to fit the OE one even at that price, as, IMO, it is critically important that this oil pressure warning circuit is in tip top working condition. ....... but then, that't me.