hi everyone,

how many oil pressure senders are there in the x300?

2 (one for the pressure gauge and one for the light)

or

1 (to feed both the gauge and the light)?

reason I ask is because mine was leaking (smaller one by the oil filter housing with a single connector), and I replaced it with another used one until I get the new one next week, and now gauge reads zero and oil light is on as well.

This happened right after I replaced the switch so it's not a faulty oil pump, or a legitimate drop in oil pressure.

I have found listings for 2 sensors online, and to add to the confusion, there is a redesigned sensor with a piece of resistor built-in a small wire harness that's supplied with the new gauge.. mine didn't have this resistor thingie either...

anyone with experience, please chime in.

cheers

 

OK, firstly only ONE. Gauge and light from the same unit.

The original was LND5640AB. This was a variable resistor style sensor.

The replacement is LNA5642CA, and is a "switch style" sensor, with a resistor wire included. This style "pegs" the oil gauge at a pre-determined needle setting, to keep the driver "warm and fuzzy", and as long as there is some oil pressure that is what the gauge reads. The original (above) did have the gauge fluctuating with engine revs, and that upset some owners. Us of the "old school" are quite used to this event, especially us V12 owners.

There has been some discussion about the gauge being "ECU driven", but I dont think the X300 had this set up. I think?? that came with the X308, but am really unsure.

 

The switch/resistor (8 psi set-point) was a TSB and the bulletin proscribed refreshing the instrument pack via WDS after fitment. Motorcarman speculated perhaps it was to get the needle to run at the mid-mark. I fit one w/o the WDS step and it ran just shy of middle mark. Now, a coupla years on and several hook-ups to Mcm's WDS later, I run just proud of the mid-mark. Sorry, don't know/ can't remember if he ever did the isnt-pack update.

 

thank you both

the local parts place specializing in jag parts has one on order for me for next week.. and he quoted me $12 (new).. I doubt it's the new revised one with the resistor as they seem to go for $35-$60 online... I will have to see what they are giving me next week, and see if it works.

I'd personally prefer a gauge that moves with engine rpm rather than one that just shows me a constant value... same with the coolant temp...

 

Yes, it's too bad we can't use Whitexkr"s Realgauge like I have in my XK8. It's good when you know what's going on up front.

 

update:

Installed the new pressure sensor (it didn't come with a harness), and now the gauge works, and oil light is off, although the gauge is pretty centred at all times (idle, cruising speed, under load, etc), so I am not sure if the gauge really displays the actual oil pressure or not... the sensor was pretty cheap.

 

The gauge is a glorified idiot light. As long as you have over about 8 lb. pressure it reads mid-scale.

 

Is it possible to retrofit the sensor from an XJ40 to the X300XJR I would also like to have a real oil pressure gauge instead of the middle displaying one

 

If the instpk was configured with WDS for the updated switch and resistor, then I don't think it will operate correctly with a proper variable sender but I don't know. I have not seen a way to UN-CONFIGURE the INSTPK once the update has been performed.

I NEVER did update aholbro1 instpk so you should be good to go if you find a proper sender.

bob gauff

 

Hi would you kindly provide detail of the sending unit part number and detail of the store you bought it from, seems the price is good. Thanks.