Is oil vicosity related to oil pressures?

[MuddyTroll]

Does using a thicker oil increase the oil pressure?
I am a little concerned that since doing my last service, I may not have chosen a thick enough oil. Ever since I did it, I have not been able to reach the same oil pressures as I did with the old oil. It has dropped by about 30%.
This means that it is now under spec
Specs say to use SAE 20-40
I used SAE 15-40
Any help would be great thanks.

[brad-chevlux]

The short answer is yes.

The long answer depends on alot of things. but in your case, I'd say the oil you took out was a 20w50 possibly a 60.

if you don't want to spend the extra on 11L of new oil and you don't mind using oil additives, you can put a bottle of moreys or lucas oil stabilizer in.
That should fix the oil pressure for now, then just use a 20w50 next time.

[dont_follow_me]

what is the 'normal' oil pressure for the td42, at idle and at around 2000rpm on a warm engine.

[MuddyTroll]

Thanks 'brad-chevlux'.
I'd rather not take the risk. If changing the oil is going to bring up the pressure then that is alot better than a new oil pump or worse.
I just needed to understand why I had lost that pressure.

And to answer 'dont_follow_me'
The specs in the manual say around 75+kpa at idle and 270+kpa at 3000rpm.
My engine does this comfortably when cold, but after it warms up (specs say to take readings from warm engine) I get around 50kpa @ idle and 190kpa @ 3000rpm.

Thanks again for the help lads.

[Yom]

what brand of oil did you use?

ive gone back to Caltex delo 400 for the time being and I've noticed the oil pressure drops right off once its warmed up, where as the Shell rimula x i was using beforehand maintains a higher oil pressure at all times.

delo 400 and rimula x have the same viscousity.

I am slightly puzzled by this and im considering not using the delo400 again.

[canuck]

Personally, I would double check the pressure with a mechanical gauge: at cold, hot on idle and hot at 2100 rpm. On both my rigs the stock oil pressure gauge reads all over the place. I use both the Shell and Delco mineral oils and have found them to be excellent.

[harvey]

Am I right in also thinking that not enough oil in the car will drop oil pressure? If so, it might seem a simple question but, have you checked you put in the same amount or a little more oil into your car than you drained out of it? Just trying to cover all bases for you on this one.

[dont_follow_me]

by the workshop specs, then the factory gauge should read 0.5kg/cm2 at idle and 3.5 kg/cm2. Mine is pretty much at that but with the way the factory gauge is calibrated, it isnt easy to read exactly what the oil pressure is. I mean the gaps between the lines really is too far apart and leaves you guessing what the actual reading is.

I think I might fit an aftermarket gauge that reads in psi or kpa which is a better calibration to read it accurately. any ideas?

[MuddyTroll]

Thanks for the help lads.
I gave the left over oil (9lts) to the brother-in-law to use for his service after filling mine up. He has thrown out the container since. Can't remember the name other than to say that it was a Valvoline product SAE 15-40.
The oil I drained out of it was put in by the mechanic. It was a Penrite product (don't know what SAE). I think I'll be doing some homework on why that oil showed none of these pressure problems I am now expieriencing with Valvoline.

[canuck]

Am I right in also thinking that not enough oil in the car will drop oil pressure? If so, it might seem a simple question but, have you checked you put in the same amount or a little more oil into your car than you drained out of it? Just trying to cover all bases for you on this one.

It will only cause oil starvation at the pump = no oil pressure. Oil pressure will drop because of a defective oil pump, worn main or rod bearings and worn crankshaft journals.

[love ke70]

was probably the 20w60 penrite oil

go back to it, i have a personal thing against valvoline for no real reason, but i guess this isnt helping is it

penrite HPR diesel, like all penrite oils is a good oil, and is reasonably priced

[brad-chevlux]

was probably the 20w60 penrite oil

go back to it, i have a personal thing against valvoline for no real reason, but i guess this isnt helping is it

penrite HPR diesel, like all penrite oils is a good oil, and is reasonably priced

what a load of crap. run penrite in any engine for 12 months. then open the engine up. then look in disgust at all the crap and sludge that it leaves behind.

[cooki_monsta]

nup, i like the penrite oils

[Yom]

was probably the 20w60 penrite oil

go back to it, i have a personal thing against valvoline for no real reason, but i guess this isnt helping is it

penrite HPR diesel, like all penrite oils is a good oil, and is reasonably priced

what a load of crap. run penrite in any engine for 12 months. then open the engine up. then look in disgust at all the crap and sludge that it leaves behind.

tend to agree.

i found the quality varies too much with their HPR range of oils (was using it with another car of mine, and i'm convinced it was the reason that cars engine started dying a nasty sludgey death despite having a perfect service history - the owner before me had been using the HPR10 for a couple of years before me).

it is way overpriced for what it provides. you get much better value for money elsewhere and often a better quality product for the same price.

[brad-chevlux]

nup, i like the penrite oils

based on what?

[superzuki]

Personally, I would double check the pressure with a mechanical gauge: at cold, hot on idle and hot at 2100 rpm. On both my rigs the stock oil pressure gauge reads all over the place. I use both the Shell and Delco mineral oils and have found them to be excellent.

where do you attach a mechanical gauge to measure the oil pressure? and what would i expect to pay for one? id assume scotts or repco would sell them?

i think it might be a good idea to check mine the gauge on the dash sits at 2 bar all the time. i use shell rimular x

[redv8lux]

was probably the 20w60 penrite oil

go back to it, i have a personal thing against valvoline for no real reason, but i guess this isnt helping is it

penrite HPR diesel, like all penrite oils is a good oil, and is reasonably priced

what a load of crap. run penrite in any engine for 12 months. then open the engine up. then look in disgust at all the crap and sludge that it leaves behind.

Always ran penrite in all my vehicles an never had a problem
Currently using it in 350chev ski boat which has had penrite used in it for the last 15 years an motor hasnt needed to be touched yet. HPR 50
350 chev in a 1 tonner almost 18 years now ( this is the 2nd car this motor has been in since ive owned it ,it also has never been touched ) .HPR50
90 maverick wagon tb42 on gas, been using penrite since i bought it 3 years ago .HPR 40
79 hilux 308 v8 on gas,had nothing but penrite for 6 years . HPR 50
All of them run clean an only the tonner motor is starting to burn a bit of oil

[brad-chevlux]

was probably the 20w60 penrite oil

go back to it, i have a personal thing against valvoline for no real reason, but i guess this isnt helping is it

penrite HPR diesel, like all penrite oils is a good oil, and is reasonably priced

what a load of crap. run penrite in any engine for 12 months. then open the engine up. then look in disgust at all the crap and sludge that it leaves behind.

Always ran penrite in all my vehicles an never had a problem
Currently using it in 350chev ski boat which has had penrite used in it for the last 15 years an motor hasnt needed to be touched yet. HPR 50
350 chev in a 1 tonner almost 18 years now ( this is the 2nd car this motor has been in since ive owned it ,it also has never been touched ) .HPR50
90 maverick wagon tb42 on gas, been using penrite since i bought it 3 years ago .HPR 40
79 hilux 308 v8 on gas,had nothing but penrite for 6 years . HPR 50
All of them run clean an only the tonner motor is starting to burn a bit of oil

I worked at a car dealer for a few years. they used penrite for everything. the amount of new cars that had oil consumption problems and sludge problems was huge. about 6 months befor i started working there, they changed from valvolene to penrite. The other mechanics there all said the problems started after the change to penrite.

I also used to use HPR10 in the EF XR6 i used to have, took about 10 000km for it turn from a clean engine to being black an sludge filled.

My apprentice was using it in his 2.7 hilux too, He took the cover off the other week to check valve clearences and found the same problem.

but if you don't mind a dirty engine, go for it.

[love ke70]

well the sumps coming off mine next week for a turboi install, its been running penrite for 18 months, ill let you know if its sludgy or not.
im always happy to take peoples advice, so thanks for the heads up.

what are the best places to look for sludge? in the bottom of the sump i would assume?

cheers, andrew

[Yom]

id be suprised if you didn't have sludge, being a td42.

youll want to switch to a more temperature stable oil after the turbo conversion anyway.

the shell rimula x i was talking about earlier costs more than what you currently use but its not a waste of money - the oil stays temperature stable for longer. its been designed to cope with abuse and it does it well.

[love ke70]

rimula x was on special at super theif so i bought 20 litres for 99 bucks, much cheaper than penrite so you have me hooked so far haha.

should be fitting turbo this weekend, so condition of sump and amount of sludge after 35K on penrite HPR diesel 20W60 will be interesting.

tempted to fit a oil pressure gauge and see what difference the two oils make.

think ive got a mechanical one hanging around, might try it

[Yom]

youll probably find in that time period its not the brand of oil causing sludge it'll be the servicing of the vehicle before you owned it.


yes i saw the rimula x too, but i didnt buy as thats still $15 more expensive than delo400.

and ive got enough of that for ANOTHER oil change.

[MuddyTroll]

FYI people, just dropped in the new Penrite oil my mechanic has been using (HPR Diesel SAE 20-60) and hey presto!! pressure problems are gone.
Idle pressure is alot better and it builds pressure faster when the loud peddle is pressed. Heat doesn't effect it as badly either. The old stuff would fluctuate for no reason on a steady throttle. Penrite just sits on around 250kpa. No, not exactly spec, but I can live with that from a 270k old motor.
Hitting the beach tomorrow and this time with confidence.

[84mksd33t]

i run hpr diesel 20w60 in my sd33t with almost 300,000 in the clock. uses absolutely no oil, its a little noisy on cold starts until the oil gets up and warms a little, otherwise its ShortyIQ great....

[Yom]

15w40 vs 15w60


doesnt exactly look like magic, just a thicker oil hiding wear issues

probably what the doctor ordered i guess. its not worth rebuilding it at 270,000km thats for sure.

[MuddyTroll]

Just got back from the beach run.
All went very well. Took a bit more loud peddle to build the revs I needed for some of the bigger dunes but I guess the thicker oil is a little responsible there.
Still I guess you can't have your cake and eat it too. Would rather sacrifice a little pickup to protect the motor properly any day.
Pressure was much more stable throughout the day regardless of temp. Some of the sustained climbs build alot of heat which used to effect the pressure with the old oil till the cooling system could catch up. Not any more though.
All in all, very happy and thanks to all who helped with the advise.
Dave

[pongo]

rimula x was on special at super theif so i bought 20 litres for 99 bucks, much cheaper than penrite so you have me hooked so far haha.

should be fitting turbo this weekend, so condition of sump and amount of sludge after 35K on penrite HPR diesel 20W60 will be interesting.

tempted to fit a oil pressure gauge and see what difference the two oils make.

think ive got a mechanical one hanging around, might try it

you can buy oil cheaper from any truck spare parts shop. about $20 cheaper for Castrol RX super

i run hpr diesel 20w60 in my sd33t with almost 300,000 in the clock. uses absolutely no oil, its a little noisy on cold starts until the oil gets up and warms a little, otherwise its ShortyIQ great....

Most wear is done at start up, thats why taxi's can get over a million kays from one engine cause they are always warm.


Ive seen truck engines get stripped at 1.3 million that run rx super. No sludge, all clean like you could eat your dinner off the inside of the rocker cover. I know its not a jap motor but i still use it in mine and have no dramas whatsover.
Its a very high detergent oil so if your motor is old and sludged, chances are youll stuff it running rx super

And on a side note, since running my old girl on vege oil, i dont seems to have as dirty oil and there is bugger all soot.

[love ke70]

sump came off mine last night, looks fuggin clean for a diesel ill tell ya.
nothing in the sump but left over oil that doesnt drain, and everything i can see looks sludge free.

who knows the differences with the early and later TD42's?
mines a 97, but has oil squirters, i thought they ditched them in 95? or did they only lighten the pistons and rods and thin out the liners?

cheers, andrew

[azzad]

Its a very high detergent oil so if your motor is old and sludged, chances are youll stuff it running rx super

Is this fact or hear say?

Dazza

[Yom]

its based on a bloody good theory.

oil sludge buildups can occur anywhere throughout the motor. a sludge buildup could in theory be dislodged by a high detergent oil and then blockup an oil gallery somewhere (not to mention how quickly your oil filters would block up and if you're that sludged up your oil bypass valve is probably not in the best condition either and not reliable.... yadda yadda yadda).

Basically while i believe it could very well happen, if you DO kill your motor from using a high detergent oil it was only a matter of time until it died from other causes (relating to the crap servicing) anyway.