My good series 2 XJ6 continues to scare me.

I did a 300km round trip on Saturday up to one of the largest swapmeets in Australia. To make things more challenging it was a 35 degree C day and I was towing a trailer. When arriving in the morning after around 150km I got caught in bumper to bumper traffic for 45 minutes trying to get in to the venue, in what was likely already 30 degree heat.

On the positive side the temeragure gauge stayed within normal (although idle did get a touch grumpy) and I did not appear to use any fluids during the trip (other than lost of petrol as I was towing a small trailer).

On the down side the oil pressure gauge is scaring me more and more. after the first half hour or so at 100kph the oil pressure dropped off to 30 at speed. While I was sitting in traffic outside the venue it dropped to 10 just after I stopped and was below 20 the whole time I was in queue.

The oil is slightly over-full (has been since the car was serviced a month ago), looks pretty clean, and the oil light did not come on at any point in the trip, but comes on when I start the car, so I assume it works.

Is it likely that the oil light or gauge is faulty if I am seeing as low as 10 on the oil gauge at idle after a long drive without a warning light? Could it be a wire with poor insulation to one or the other?

 

Personally, I don't see anything to be especially alarmed about.

- Normal for pressure to drop as the oil gets hotter
- Normal for pressure to be generally lower on an older engine
- Normal for pressure to be lower at idle
- Normal rule-of-thumb is 10psi per 1000 rpm
- Most o/p warning lights are set for 3-5 psi



Cheers
DD

 

Thanks DD,

It is just very different to my other cars I suppose, which is the cause of my fears.

My 74 Daimler Sovereign 6 has never dropped below about 35psi that I have seen

My 1967 Volvo runs quite a high oil pressure (it can get as high as 90 when accelerating from cold) and stays around 40 warm

so to see something so much lower in an engine type I have been brought up to believe can be temperamental had me somewhat concerned.

On another note I now know for certain that it is the regulator playing up on my alternator causing occasional lack of charging. I will add some photos in the next couple of days in the hope someone can identify the reg/alternator so I can source a replacement, as it seems a pretty obscure make.

 

I hear ya, but.....

What are ya gonna do? You could replace the main bearings, rod bearings, and oil pump and probably restore full oil pressure. If that sounds palatable to you then break out the tools and dig in!

If that's not in the cards....then quit worryin' about it and soldier on . Be easy on the old girl and she'll probably live for many more years ....even with lower-than-optimal pressure.


Cheers
DD


PS- Have you confirmed that the pressure gauge is accurate?