[Tools R Us]

Originally Posted by Waggoner5

Back to my original post. My factory gauge reads 0 when there is 25-35 psi oil pressure. Others do the same thing. The question was simple, and has been answered. My gauge or sender has an issue along with DTaylors. We will fix it. I was hoping that the gauge could be modded as easily as the water temp to use the full range of the gauge more accurately, but it can't so we can stop worring about it.

It sounds like ether the gauge or sender is bad, the FSM procedure for testing;

[Rookie2]

Originally Posted by Waggoner5

I was hoping that the gauge could be modded as easily as the water temp to use the full range of the gauge more accurately, but it can't so we can stop worring about it.

Maybe I'm beating a dead horse here, but it just doesn't seem like you all are getting it. A properly acting gauge DOES use full range, or close to it. Mine starts at zero when engine is off (no oil pressure) and slightly above the 2/3rds mark warmed up under medium throttle. Are you wanting it to peg out instead under this condition? Like RT said, if you fix whatevers wrong with yours, you'll get the kind of full range action you're looking for.


Rookie2

[Cruiserdrew]

Originally Posted by Waggoner5

Back to my original post. My factory gauge reads 0 when there is 25-35 psi oil pressure. Others do the same thing. The question was simple, and has been answered. My gauge or sender has an issue along with DTaylors. We will fix it. I was hoping that the gauge could be modded as easily as the water temp to use the full range of the gauge more accurately, but it can't so we can stop worring about it.

I've had my 80 since 1999 and it has behaved this way from day one. I replaced the sender several years ago, no difference. I am sure it is the gauge. I actually find it annoying that at hot idle it reads very low (sometimes almost zero) yet if it were a problem, the motor would have crapped out years ago. If the bottom of the scale is 35 PSI and the 2/3 bar is 75 PSI that is not a useful gauge unless you know exactly what each part of the gauge is telling you. Every other 97 I have seen reads the same-scary low at idle and near 2/3 at freeway speeds. I don't like it and would like a gauge mod that is CALIBRATED by reality. I would much rather have a gauge where the bottom was zero and the top was 100. Then, all the readings could be put in context. If I really have zero oil pressure at hot idle, my motor is in trouble. If it's really 35 psi at hot idle, then it will run forever. The way it is now, it only causes stress, and doesn't provide any useful information. An idiot light would be better!

More useless info-I attached a calibrated gauge to my FJ40 which always reads just above the half way mark at speed, and just below it at idle. I got 4O psi at 3000 rpm and 45 psi at 2000 rpm. Both were the same on the guage. Idle was 30 psi. Clearly that guage is more of an idiot light as well. I can tell from the measurment that the motor is a bit tired, but you could not tell that from the gauge.

Anyway, I think Toyota could do better.

[Darwood]

Originally Posted by RavenTai

what would you do to it?

mine spends most of its time at 2/3 mark (relief pressure) and the rest at the 1/3 mark at hot idle, seams just fine to me.

If your 1FZ is showing something different than might be a fault not as by design

Mine works like Ravens. It never seems to get below the 1/3 mark.

[DTAYLOR]

Originally Posted by extremetoy1

okay, this one is easy.... why would one need a mod to the gauge? there isnt too many automotive engines made that wont survive with only 5lbs of pressure....

So if one had this mod what would you expect it to do? it goes up when the RPMs do and goes down when the RPMs do as well.
If it were to fluctuate would you even notice? there wouldnt be any problem if it did (it is normal to go up and down a bit) the temp mod helps make a more sensitive temp reading so when it does begin to move you can shut it down before you do damage to the engine.

The oil pressure will not cause detrimental damage if fluctuating... that is common.

I don't think anyone expects a gauge mod to change the actual pressure. What we need is more accurate data about what is actually happening, without having to wonder. Just like Andrews says, we just don't want to have to be concerned about it.

It's the impending threat of a big problem that drives me nuts. I don't want to put up with that from my Land Cruiser, I have a and kids for that.

[83bj60]

Originally Posted by extremetoy1

okay, this one is easy.... why would one need a mod to the gauge? there isnt too many automotive engines made that wont survive with only 5lbs of pressure....

So if one had this mod what would you expect it to do? it goes up when the RPMs do and goes down when the RPMs do as well.
If it were to fluctuate would you even notice? there wouldnt be any problem if it did (it is normal to go up and down a bit) the temp mod helps make a more sensitive temp reading so when it does begin to move you can shut it down before you do damage to the engine.

The oil pressure will not cause detrimental damage if fluctuating... that is common.

I disagree. You seem to attach a lot of importance to the temperature and hardly any to the oil pressure. On a 1HD-T engine, pressure on the connecting rod during normal operation can be extreme, and although the main cause of problems with the early engines is poor OEM bearing quality, the fact remains that direct diesel injection is very, very hard on the bearings and it has been shown that if oil pressure is on the low side (like when the engine is lugging), real damage can be done.

Having an oil guage that will warn you if the oil pressure is too low for comfort is a plus. Although I've always listened to my engines when I drive, knowing the oil pressure gives me an extra warning and it would help greatly if the gauge went all the way full scale instead of maxing out at the middle.

I've thought about the reason for this common problem on the 1HD-T engine today while driving, and I now believe the problem may simply be related to sender wear caused by excessive cursor vibration on the winding within the sender, increasing its resistance. Maybe a damping mechanism on the sender would solve the problem. The vibration itself could be caused by the sharp direct injection pressure variation on the connecting rods. Of course, this is just a theory.

[extremetoy1]

Originally Posted by DTAYLOR

I don't think anyone expects a gauge mod to change the actual pressure. What we need is more accurate data about what is actually happening, without having to wonder. Just like Andrews says, we just don't want to have to be concerned about it.

It's the impending threat of a big problem that drives me nuts. I don't want to put up with that from my Land Cruiser, I have a and kids for that.

more accurate data??! the oil has pressure... thats about they only data you can get on oil pressure. if it has it you are fine, does your needle move? then your oil pressure is fine does it not move and the red light comes on? then you have problems.

the oil pump varies pressure throughout the rpm range so a "more accurate" gauge will do exactly that- move up and down with more accuracy (is the OEM not accurate?) if you want numbers use decals.....

many different model Toyotas do the same thing, some gauges vary slightly more than others but they are all within a certain parameter of one another.
the pump is a gear driven pump and it is not going to just "quit" on you.

Originally Posted by 83bj60

I disagree. You seem to attach a lot of importance to the temperature and hardly any to the oil pressure. On a 1HD-T engine, pressure on the connecting rod during normal operation can be extreme, and although the main cause of problems with the early engines is poor OEM bearing quality, the fact remains that direct diesel injection is very, very hard on the bearings and it has been shown that if oil pressure is on the low side (like when the engine is lugging), real damage can be done.

Having an oil guage that will warn you if the oil pressure is too low for comfort is a plus. Although I've always listened to my engines when I drive, knowing the oil pressure gives me an extra warning and it would help greatly if the gauge went all the way full scale instead of maxing out at the middle.

I've thought about the reason for this common problem on the 1HD-T engine today while driving, and I now believe the problem may simply be related to sender wear caused by excessive cursor vibration on the winding within the sender, increasing its resistance. Maybe a damping mechanism on the sender would solve the problem. The vibration itself could be caused by the sharp direct injection pressure variation on the connecting rods. Of course, this is just a theory.

1. it only takes 5 lbs of oil pressure to get it where it belongs, and a qaulity oil will play a big roll in keeping things lubed.

2. it wouldnt be a gauge then, gauges are meant to read not to warn you.
maybe a new thread about an oil pressure warning sensor?!- this thread is about wasting time trying to mod. a gauge that already works fine for what it was made to do.

3. hmm lets see the vibration in a diesel caused by direct injection.....no, maybe detonation perhaps? like each time it fires (I know they dont have a spark plug)...when it is at the top of its stroke and the fuel detonates is what I mean.

[IBCRUSN]

Thank you extremetoy!

If all this is about the low psi at idle you had better take Tools advice before monkeying with the existing gauge system. Why go through all the hassle to mod the gauge or install an after market unit only to find out the original unit was not functioning correctly? If it's still a concern install an idiot light with the desired tripping psi setting?

It's way too OCD to screw with things that don't need screwing with. I can understand on some of the diesel models because of the big end bearing issues but for 1FZ and 3FE it's a non-issue. When was the last time anyone on the board posted they locked up their engine?

Okay, enough ranting.

Seriously though this sure seems like more drama than is really necessary.

[DTAYLOR]

Extremetoy,

I hear you. Still, I would like to see an actual reading of pressure.

Yes, I am the President, and President - elect of my OCD club, and have already registered to run for consecutive terms for the rest of my life, and 200 years beyond my normal life expectancy.

Now that we have documented that, who can tell us how to mod this gauge?

[IBCRUSN]

Here is a thought. Once you can determine that your current system is functioning correctly find a means to hook a deadman to the sending unit. By that I mean a fixture that can impart controllable pressure on the sending unit. Once you have something setup crank up the pressure and note as such on your gauge face. Reinstall gauge cover and reinstall gauge assy and you're done.

[DTAYLOR]

IBCRUSIN,

That sounds OK, but how to "print" digits on the gauge?

I thought we could find a way to "lay over", or "insert" a correct size gauge into or over that slot, that a reasonable mod would be born. We would need to find an aftermarket gauge the right size.

Gary, possibly a suitable marine application out there?

D

[83bj60]

Originally Posted by RavenTai

sure, there is not much to the oil pressure gauge as compared to the water temp gauge.

there is a "U" shaped piece is sheet metal, the closed end hangs in free air, one part of the open end is hard mounted the other is hooked to needle via a linkage, a wire winds many turns around one of the arms of the "U"

one side of the wire is switched + from the ignition switch. the other is grounded through a variable resistor in the sender,

I assume this forms an electromagnet and the two arms of the "U" either attract or repel each other in proportion to the current going through the wire and this moves the needle.


sorry for the poor pictures, it was dim and shutter times were long.

Raventai, the way you describe it, seems to me to be a lot like the ones on the 60... Are these Yazaki brand meters? The winding would be a heating coil and the U shped piece, a bimetal.

Anyway if that's the case, I can't see how the receiver unit can go wrong, it's very sturdy. Hmmm.... Tweaking the sender may be more problematic... But at $400 apiece, it may well be worth taking apart and twiddling with...

[e9999]

I don't get this.
If you want numbers, buy an aftermarket gauge and sender that will give you real numbers, and stick it somewhere. Why futz with the OEM gauge?

[RavenTai]

Originally Posted by 83bj60

Raventai, the way you describe it, seems to me to be a lot like the ones on the 60... Are these Yazaki brand meters? The winding would be a heating coil and the U shped piece, a bimetal.

Anyway if that's the case, I can't see how the receiver unit can go wrong, it's very sturdy. Hmmm.... Tweaking the sender may be more problematic... But at $400 apiece, it may well be worth taking apart and twiddling with...

Yes Yazaki Meter,


a heater eh? that would have been my second guess but I did not see the two pieces required to make the bi-metal, they must be laminated together.


$400 for a sender? ouch,

[IBCRUSN]

Originally Posted by DTAYLOR

IBCRUSIN,

That sounds OK, but how to &quotrint" digits on the gauge?

I thought we could find a way to "lay over", or "insert" a correct size gauge into or over that slot, that a reasonable mod would be born. We would need to find an aftermarket gauge the right size.

Gary, possibly a suitable marine application out there?

D

By the time you go through the hassle of putting "pretty" numbers on it you could have installed 2 or 3 aftermarket gauges. If it were me I would go through the process I mentioned and put a dot (sharpe or ??) for certain pressures, maybe a low limit psi and relief psi, anything more than that is a waste and confusing.

[maverick_sr71]

Originally Posted by e9999

I don't get this.
If you want numbers, buy an aftermarket gauge and sender that will give you real numbers, and stick it somewhere. Why futz with the OEM gauge?

It's not about numbers. I had a 1KZ-TE (3 litre Diesel) that in the middle of a 1200km trip had the thermostat and radiator cap fail at about the same time. The result was coolant being pumped straight into the overflow bottle and out of the car. In a 7 litre system the car had lost 5 litres.

"Why weren't you watching the temp gauge?", I hear you all say. I was. I senced something was wrong when the auto kept dropping out of overdrive on hills it would normally do with ease in overdrive. The only indication I had on the dash that there was a problem was the oil temp gauge, the pressure had dropped about 3 needle widths below normal.

It's not about numbers, it's about getting the gauge to read between the 1/3 and 2/3 mark purely for indication. As I've said before, the diesel 80's often had this problem from day one, but the actual oil pressure is correct. It is a gauge fault, I grant you that, but replacing the gauge in a diesel 80 doesn't fix the problem, it's been tried several times by many people.

[RavenTai]

on a side note not sure about the temp gauge on the diesels but the one for 1FZ in the states has a large dead spot.

has anyone checked for compatibility of the 93-97 temp gauge mod with the AUS gauges?


http://forum.ih8mud.com/80-series-tech/64252-93-97-coolant-temperature-gauge-modification.html

[concretejungle]

Originally Posted by Waggoner5

That is possible. My truck and Dans both show really low oil pressure at idle. Mine I know for sure is 25-35 hot but shows 0 on the factory gauge. I was hoping to see something more accurate like the water temp mod.

here is my thread addressing this. http://forum.ih8mud.com/showthread.p...t=oil+pressure

and in the pictures associated with the thread above, that pic is actually above where the needle is under hot oil conditions. Usually it almost sits on the bottom.

[maverick_sr71]

That needle position (in the link) would be acceptable to me if the engine is hot and at idle.

I've been on the LCOOL forum (Land Cruised Owners On Line) for the last 5 yrs and I've not heard of Oz spec vehicles, petrol or diesel, having this problem with their temp gauges.