Low oil pressure with 1hz diesel motor (1 Viewer)

[sunrk]

Anyone ever looked into why their diesel motor oil pressure is always low? My very original 1hz doesn't blow smoke that's noticable above what'd be considered normal, and it's got a full fill of oil. I did an oil change with new filter recently - I use delo 400.
When running and the motor is hot and idling, the oil pressure is like 1/6 on the gauge, and when driving it never gets to 2/3 always sitting between 1/3 and 1/2. I know the gauge is not calibrated.

i don't know anything about the oil pump setup or how tell why or how oil pressure seems to be low. I'm aware there is a very expensive sensor in the oil system but I don't think that's the pressure sender. Can the pressure sender itself simply go bad? Seems the senders (genuine ones) are easy to get - can they simply be unscrewed and replaced without losing the oil when the motor is off and cold?

 

[Dusten]

Anyone ever looked into why their diesel motor oil pressure is always low? My very original 1hz doesn't blow smoke that's noticable above what'd be considered normal, and it's got a full fill of oil. I did an oil change with new filter recently - I use delo 400.
When running and the motor is hot and idling, the oil pressure is like 1/6 on the gauge, and when driving it never gets to 2/3 always sitting between 1/3 and 1/2. I know the gauge is not calibrated.

i don't know anything about the oil pump setup or how tell why or how oil pressure seems to be low. I'm aware there is a very expensive sensor in the oil system but I don't think that's the pressure sender. Can the pressure sender itself simply go bad? Seems the senders (genuine ones) are easy to get - can they simply be unscrewed and replaced without losing the oil when the motor is off and cold?

On the 1hdt it's frequently noted that a cleaned or new sensor will read higher.

If you're honestly concerned with oil pressure install a mechanical gauge and verify what actual pressure is.

 

[sunrk]

I'd like to do exactly that. I already have a Watchdog TM2 in the 80 telling me the engine (coolant) temp.

Just need to figure out a modified sender setup. I've used dual-contact (calibrated gauge signal + warning contact) in cars but that's probably not useful with a diesel motor. Calibrated gauge signal plus maintaining the factory gauge operation would be the practical option.

 

[DivByZero]

I don't recommend a gauge, calibrated or otherwise, to help with feedback on oil pressure issues. It's a nice visual double-check, but in terms of actually notifying you of an issue, it does a poor job. By the time you notice critically low oil pressure on a gauge, the engine could already need a rebuild.

In my HZJ80, I've gone a bit paranoid. I've kept the factory oil pressure gauge, but I've added an oil pressure switch too. That switch drives an oil pressure warning light I've added to the factory cluster right next to the oil level warning light, replacing the unused A/T temp warning light on my manual 80. I also tied the pressure switch signal into the oil pressure alarm function on my engine monitor. All up, it means I have the factory coolant temp gauge plus a digital readout of head temps, with a buzzer on overheating, as well as the factory gauge for oil pressure, plus two lights and a buzzer on low oil pressure.

 

[sunrk]

Neat solution. How did you actually add that extra function? My engine monitor is a still a basic tm2 that just does engine temp but I'm considering upgrading to a different monitor that can have extra inputs.

I presume you replaced the Toyota factory oil pressure sender with something that has dual outputs like one of the VDO units people fit in cars that has one output for a gauge and one output for a low-pressure warning light? I think (not sure) the thread of the factory sender might be M10 x 1.0 thread.

 

[DivByZero]

Neat solution. How did you actually add that extra function? My engine monitor is a still a basic tm2 that just does engine temp but I'm considering upgrading to a different monitor that can have extra inputs.

I presume you replaced the Toyota factory oil pressure sender with something that has dual outputs like one of the VDO units people fit in cars that has one output for a gauge and one output for a low-pressure warning light? I think (not sure) the thread of the factory sender might be M10 x 1.0 thread.

I went pretty low tech actually. I put a t-way on the oil pressure sensor location on the block, and hung the factory pressure sender and switch off it. The gauge is wired as normal, nothing changed. The switch is wired into the light I spliced into the cluster, and into the oil pressure switch input for my engine monitor. I run one of these:

ENGINE GUARDIAN WATCHDOG COOLANT + BOLT TYPE SENSOR EG3C RELAY CONTROL ALARM NEW | eBay

ENGINE GUARDIAN EG3c (New version, fully loaded with coolant sensor & bolt type sensor). Engine Guardian EG3, This system can help to prevent overheating due to Engine Guardian EG3 - Dual Sensor Demo.

www.ebay.com.au

Great unit, I highly recommend it. Here's it fitted to my rig, with the engine stalled out to show the pressure alert triggered and the light on the dash:

 

[mudgudgeon]

Did the pressure sensor come with the watchdog?
I have a watchdog to alert me on coolant temps.

 

[DivByZero]

Did the pressure sensor come with the watchdog?
I have a watchdog to alert me on coolant temps.

No, it just has the input for it, not the switch itself. I nicked a Toyota pressure switch with the funny slide clip they use off an old Hilux in a wrecker. Or at least the clip I did, maybe I got the switch in a parts order? Can't remember now. Lots of options though, the switch is simple, there's plenty of options out there.

 

[Arkana4WD]

Anyone ever looked into why their diesel motor oil pressure is always low? My very original 1hz doesn't blow smoke that's noticable above what'd be considered normal, and it's got a full fill of oil. I did an oil change with new filter recently - I use delo 400.
When running and the motor is hot and idling, the oil pressure is like 1/6 on the gauge, and when driving it never gets to 2/3 always sitting between 1/3 and 1/2. I know the gauge is not calibrated.

i don't know anything about the oil pump setup or how tell why or how oil pressure seems to be low. I'm aware there is a very expensive sensor in the oil system but I don't think that's the pressure sender. Can the pressure sender itself simply go bad? Seems the senders (genuine ones) are easy to get - can they simply be unscrewed and replaced without losing the oil when the motor is off and cold?

Hi Cruiser Lovers. Just to put a spin on here on low oil pressure. Having a simular issue at hand and the same with another 1Hz a few yrs ago.I probably read here or another one of these sites that the oil pick up gause filter behind the pan can get clogged.Eventually i removed the pan to check it out and what i found was the pipping feed attachment bolts were loose.Some oil was being slurpped up but suction pressure was low from the gap between the pipe fitting and block.
I`m now trying to find a way to see if this one is loose some how without taking the pan off don`t i like my chances though trying to wriggle a piece of wire or peeking into the hole.Unfortunatley most likely i`ll have to remove the pan.