Oil pressure on my Trooper

My Trooper has an oil pressure gauge fitted, around town it stays around

2kg/cm at idle & 4 at double idle. On a long run at 70-80mph it goes down to about 2.2 at 3 times idle & 1.8 at idle (if I stop etc) is this an effect of the oil getting hotter & thinner due to the run etc or is it likely to be something else. The machine runs sweet as a nut with no oil use I can see. I ask in this group as the Isuzu group is crap!

Idle speed is 800rpm if it matters.

Ta

Nige

Reply to
Nige
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Why not try...uk.rec.cars.4x4 ...?

Reply to
Wolverine

Simply because the folk here are genuinely knowledgeable about this kind of thing, most folk there don't know as much as they think.

If it bother you - sorry.

Nige

Reply to
Nige

No it doesn't bother me. I just thought a general 4x4 group might be able to help. When you said you'd tried the Isuzu group, I couldn't have known you'd already tried 'uk.rec.cars.4x4'. I'm sure someone here will be able to help you solve the problem. Good luck.

Reply to
Wolverine

On or around Thu, 8 Jul 2004 19:24:50 +0100, "Nige" enlightened us thusly:

what's that in sensible units, and/or what's the spec for it? these are things you need to know.

Reply to
Austin Shackles

I'd guess that if an oil pressure gauge is fitted as standard, there would be reference to it, and it's safe working range, in the owners or workshop manual.

Reply to
Paul - xxx

1 kg/cm2 is approx 15psi, so a hot idle pressure of 27 psi or so is fine. I'd guess that the drop when hot is merely that the oil has finally come up to temperature and is nothing to worry about. What grade of oil are you using, and are you changing it regularly? For one of these motors (assuming it's a diesel) I'd suggest a CH-4 or higher rated 15W/40 and change it every 3000 mile or 6 months, and change the filter every second oil change. Don't run a lighter oil than this if you can help it as Trooper diesel motors (especially the turbo ones) have a real problem with firing lighter oils out the breather - I've built several oil separators for these to overcome this problem.
Reply to
EMB

Oil pressure or lack of it is something I think I am better off not knowing about :)

If it is still running in a weeks time, I won't be surprised but most people with a little lerning will be.

Reply to
Larry

On or around Fri, 09 Jul 2004 09:30:51 +1200, EMB enlightened us thusly:

all sounds reasonable, except that I've never understood, bearing in mind the cheapness and dubious quality of ordinary commercial oil filters, the reasoning behind not changing them every oil change. The addition cost (typical filters are no more than a tenner) makes the saving so small (if you do any amount of miles) as not to be worth it - and thereby not using a partly-blocked filter.

Modern oils are probably quite OK for 5 or 6000 mile changes in modern engines, too.

mind, your comment about not running thin oil is getting to be a pain these days. It's getting very difficult to get decent oil which isn't thin, without paying an arm and a leg for it.

Reply to
Austin Shackles

10/40 is in right now. I'll have it changed!

Cheers

Nige

Reply to
Nige

Button bashing in practice for another round of Daley Thompson's Decathlon, Austin Shackles left Shakespeare to the monkeys by typing...

Just a small bottom-holding (anal retentive) point - a partly blocked filter is more efficient. As in more efficient at removing smaller particles. Personally, I'd remove all the useless extraneous metal from around the engine and fit a Landrover ;-)

Reply to
weallhatebillgates

On or around Sat, 10 Jul 2004 12:05:13 +0100, weallhatebillgates enlightened us thusly:

teehee.

actually, the 3.1 Isuzu is widely regarded as a good engine, and would probably suit a LR quite well, provided yer an Ozzie or a heretic.

Reply to
Austin Shackles

The message from "Nige" contains these words:

I know nothing about Trooper, except that they generally are faffing about in front getting in the way on days I work offroad, I never have found out if it is the vehicle or the driver; anyway enough of this meaningless abuse and a possible reason for your oil pressure variations. Many years ago I was fortunate enough to own a Mark 2 3.8 Jaguar, in the years before Ford f***ed Jaguar and Land Rover, have you seen pictures of the the new disco J***ze is it ugly or what! saw a new Defender the other day had the ugliest big crappy plastic front on it, common platform obviously works four really ugly cars in as many years. Anyway back to the Jag when dear old Mr Lyons was in charge, this exhibited much the same characteristics, for which no explanation could be found, However one day I was talking to a man who maintained performance cars, he recommended changing the oil every 1000 miles, and this worked extremely well. His explanation was that no matter what oil you used it started to seriously break down by 1000 miles and would not stand up to stress, of course since those days you have expensive synthetic oils whic are supposed to be better! Another factor may be a pump bypass pressure release valve, which blows at too low a pressure or has a bit of grit in it having blown at some time.

Don't suppose this helps but you could try an oil change and see if things improve.

Reply to
Warwick Barnes

On or around Mon, 12 Jul 2004 15:26:10 +0100, Warwick Barnes enlightened us thusly:

it also tends to depend on use, as well as quality of oil. if you go racing, you run the engine flat out most of the time, and the oil has to work a lot harder. Makes sense to change it frequently.

some of the modern oils in modern engines are unbelievable, though. Mercedes trucks, for example, are now producing engines which, on admittedly very expensive synthetic oil, have 100,000Km oil change intervals in normal use. I daresay they have better filtration too.

Reply to
Austin Shackles

A lot of them have really high-end centrifugal filters, and "self-changing" oil whereby they replace some of their oil on a continuous basis (new oil from an onboard tank, and used oil into a waste tank). But large diesels are a very different animal from the lightweight high-speed diesels - oil changes are vital to prevent sludge buildup (I have seen some new engines with 10k mile oil change intervals that are totally blocking their turbo oil feeds by 40k miles). Good quality oil is really important - I'm not sure of what's available to you in the UK but I tend to stick with the big-name oils and avoid the "unknown" cheaper oil.

Reply to
EMB

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