100 HDJ oil pressure

this is fine, no problem at all. Mine has 190K on it and Ive had it 3 years.
Remember that these factory gauges are not "calibrated" at all. Mine sits at half when cold idling and half when hot at highway speed.
However, watch the gauge, as just after I bought mine, and I was crossing the Nullabor, it starting fluctuating all over the place. I rang the guy I bought it off who spoke to his BIL (mechanic) who spoke to Toyota mate and apparently it was a factory service replacement item. Not a recall. So I spoke to Toyota SA who knew nothing.
Got the number of the service item-"oh yeah your right", and fitted a replacement sender unit on the spot.

If you are really concerned fit an aftermarket gauge and run it.

If you are worried fit an aftermarket oil pressure gauge.

My 2005 TD idles at 30lb and at 90kph in 4th is 58lb.

When starting in the morning it goes up to as much as 80lb till it warms up

You can buy a good autometer gauge and a union which allows you to fit both the gauges for about $115 at Autobarn.

The union is brass and fits in where the sender comes out and has a thread in the side so you can fit the outlet for the second gauge.

A engine temp gauge and a low water alarm is a worthwhile investment as well

Get one here www.enginesaver.com.au


Cheers

Toyota oil pressure gauges have never been the full quid. They lose calibration fairly easily. Yours sounds normal - sounds like its still working OK!!!!
I've never take any notice off them - I'm very happy that I have the same engine as yours and no oil pressure gauge!
They do have a very useful oil level warning light, so if you lose oil rapidly, a light comes on.

he oil pressure senders are know to be suspect on the hz models, I expect the same for HD models. I recently had a sender fail and then had it replaced- this process itself is not without loss of hear beats - seing the gauge go to zero pressure. With a new sender it now behaves as I wouild expect:
On cold oil idle, there is higher pressure that warm idle.
Warm idle is lower pressure that at operating revs.
3K rpm = around 3/4 on the pressure gauge.
More enginge revs - an increase in oil presure.

I knew the senders we suspect but didn;t pay much thought to the observations that the gauge did not respond in the way I though it should, I though my sender must have been OK as it was working. After replacing the sender due to failure (around $100), oil pressure reads as I would expect and as a gauge watcher I am more comfortable.
Cheers
Paul.

The Toyota manual suggests 3lb at idle and 36lb at 3000 revs is satisfactory

Hope mine never gets that bad.

Today it was 27lb at hot idle 58lb in 4th at 85kph outside temp 33

Towing 2853kg van

Engine running at 82deg

Front tyres 43lb 38deg temp

Rear tyres 46lb 48deg temp

Van tyres 46lb 44deg temp.

Hows that.




Is a 2005 TD just coming up to 130,000