Hi All -

I think I have the answer to my own question 1) pull sending unit, check pressure 2) switch to heavier oil - but I thought I'd bring it up anyway, as I'm sure others may experience this as well.

I've had a 1995 XJ6 for 1.5 years - no problems with oil pressure. 82K miles. Very well maintained. Running 10w-30, per the manual. I know others may run heavier, but I like the extra energy savings of 10w-30.

But at hot idle (800 RPM) - the oil pressure light sometimes comes on, even if the needle is showing just above 0. Happens occasionally. Of course, when driving, the light doesn't come on.

I don't suspect this is an oil pressure problem, or a sending unit problem. It has neither gotten better or worse since I've owned the car.

I'm just about to get my oil changed - might switch to a higher grade. Any master techs out there able to chime in on this being common on Jags of this age? You all think 10w-40 would do it? Or 20w-50?

Thanks -
Owen

 

"I don't suspect this is an oil pressure problem, or a sending unit problem. It has neither gotten better or worse since I've owned the car."

Help me here. Why do you not suspect the two primary causes of this indication? Am I reading this sentence wrong? If its not the pressure and not the sensor, what might it be?

Ther was, in fact a design change to eliminate low reading oil pressure. It involved changing the analog pressure sender for a switch, with a series resistor to set the guage at 1/2 scale if the switch closed. Since you seem to have a reading other than 1/2 or zero, maybe you do not have that mod. Check with the dealer or google for tsb 15_33 NOV 95.

 

Nice job, Sparkomundo.

Additionally, I will add that 10W30 in a warm climate is on the low end of the acceptable viscosity scale for an AJ16 engine. I use 20W50 for temperatures consistantly above 40 F, and 10W40 for our winters here in Ohio: 0 F is usually as bad as it gets. If you look at the chart in the handbook, it will help you make a better choice depending on your climate.

 

Ross -

Thanks for your reply. I haven't yet posed the question to my dealer - I'm asking here first, as this is an open forum. My question isn't whether my logic is sound, it's whether this is a common problem. I've heard others ask it (tho it seems old posts are deleted??) and I recall the response being that this was fairly common.

If not, then I will begin futher diagnostics.

 

Thanks Jag Tech - looking at it right now, the manual explicitly and repeatedly recommends 10w-30 - and the graph shows it covering all temp ranges. Didn't earlier models of Jag with the Aj16 recommend 20w50? I suspect the 10w30 recommendation is part of the energy conservation and better fuel mileage - not so much it being the ideal grade for this engine.

The car will be between SC and NJ this fall/winter. I'll try a heavier grade. Thanks much.

 

I had my needle bouncing when it was cold. Had to replace the sender.




Brian

 

Owen and Brian:
It sounds to me that you both have the "old" version of pressure guage- with a real indication of pressure. I sure wouldn't change that to the switch and fake guage reading. However your indication of low pressure at idle is probably just that- low pressure. ( I don't know about changing the sensor). What little fuel you might save seems small compared with peace of mind that your engine is lubing all the parts. I run 20-50 petroleum oil myself in my XJ6, since my engine has 250,000 miles. BTW, it burns about one qt. in the 5-6 k change interval I use.