[dsfra]

I'm about to run out of the 5-year, 60,000 mile drivetrain warranty, so it's time to install some real gauges. AllData shows the switch for the oil pressure idiot light toward the top front of the block on the passenger side, but I sure can't see it from above; single wire grey connector. May have to pull the RF wheel and go in thru the inner fender to find it. Is it tucked up under the P/S pump maybe? Of no less importance, anyone know the thread size for the oil pressure switch? NPT or BSPT or some goofy metric thread perhaps? The dealer service and parts departments have no idea, and they seem less than interested in finding out. I don't particularly want to pull out the old switch and puke [coolant] oops should say ["oil"] all over just to find out the size and then reinstall it and put the [coolant] oops should say ["oil"] back in, then go shopping for a gauge and sender. Might go to AutoZone and pick up a cheap replacement (PS254 $13 vs. $60 at Toyota) and compare it with the threads on one at the dealer parts department. I'm not sure that I want to simply replace the idiot light switch with the gauge sender, since for all I know some processor somewhere in the bowels of the vehicle is doing something with the oil pressure switch value. The wiring diagram seems to show it as a simple normally open switch between ground and the LED in the "Combination Meter Assembly". Has anyone come up with a clean way of having both the original switch and a gauge sender - a T-fitting of some sort or an adapter or whatever? Can anyone with a gauge installed tell me what sort of oil pressures you're seeing?

And does anyone know where there might be a good spot to tap in an oil temperature gauge sender? I don't really want to hang too much weight from the smallish oil pressure switch threads in the aluminum block using a maze of adapters, nor do I want to introduce any new potential points of failure by cutting into oil lines or whatever. Plus, it really needs to "see" circulating oil - not the stagnant oil at the end of a dead-end. If it comes to it, any opinions regarding simply using a big hose clamp to clamp the temperature sender against the aluminum oil filter housing? With lots of thermal paste filling any air gaps? I know it would be real cheezey, but I don't particularly care what value the temperature gauge shows since I'm more interested in watching for a deviation from “normal”, so accuracy wouldn’t be of critical importance. Looking for qualitative, not quantitative, information. Any suggestions about what would be a good choice for these gauges - electrical not mechanical? Looking for something smaller than the 2" standard diameter, and digital seems to be pretty pricey - analog would be fine. I don't need real good accuracy and don't want to get carried away spending money, but nothing too crappy, please.

Thanks.

[Edit] P.S. Does anyone know how to change the "title" of a thread? I saved the initial posting, forgetting to change it from "Oil Pressure" to "Oil Pressure and Temp Gauges", and now it won't let me change it!

[1engineer]

Originally Posted by dsfra

I'm about to run out of the 5-year, 60,000 mile drivetrain warranty, so it's time to install some real gauges. AllData shows the switch for the oil pressure idiot light toward the top front of the block on the passenger side, but I sure can't see it from above; single wire grey connector. May have to pull the RF wheel and go in thru the inner fender to find it. Is it tucked up under the P/S pump maybe? Of no less importance, anyone know the thread size for the oil pressure switch? NPT or BSPT or some goofy metric thread perhaps? The dealer service and parts departments have no idea, and they seem less than interested in finding out. I don't particularly want to pull out the old switch and puke coolant all over just to find out the size and then reinstall it and put the coolant back in, then go shopping for a gauge and sender. Might go to AutoZone and pick up a cheap replacement (PS254 $13 vs. $60 at Toyota) and compare it with the threads on one at the dealer parts department. I'm not sure that I want to simply replace the idiot light switch with the gauge sender, since for all I know some processor somewhere in the bowels of the vehicle is doing something with the oil pressure switch value. The wiring diagram seems to show it as a simple normally open switch between ground and the LED in the "Combination Meter Assembly". Has anyone come up with a clean way of having both the original switch and a gauge sender - a T-fitting of some sort or an adapter or whatever? Can anyone with a gauge installed tell me what sort of oil pressures you're seeing?

And does anyone know where there might be a good spot to tap in an oil temperature gauge sender? I don't really want to hang too much weight from the smallish oil pressure switch threads in the aluminum block using a maze of adapters, nor do I want to introduce any new potential points of failure by cutting into oil lines or whatever. Plus, it really needs to "see" circulating oil - not the stagnant oil at the end of a dead-end. If it comes to it, any opinions regarding simply using a big hose clamp to clamp the temperature sender against the aluminum oil filter housing? With lots of thermal paste filling any air gaps? I know it would be real cheezey, but I don't particularly care what value the temperature gauge shows since I'm more interested in watching for a deviation from “normal”, so accuracy wouldn’t be of critical importance. Looking for qualitative, not quantitative, information. Any suggestions about what would be a good choice for these gauges - electrical not mechanical? Looking for something smaller than the 2" standard diameter, and digital seems to be pretty pricey - analog would be fine. I don't need real good accuracy and don't want to get carried away spending money, but nothing too crappy, please.

Thanks.

I'm not telling you not to do this (I don't care, although an idiot light will do the exact same thing as what you are trying to accomplish) but you need to understand a few things: Pressure in one part of the system is the same as pressure in the other part of the system, regardless of location. Unless you have different circuits, valves or orifices then the value won't change, at least not enough to pick up on a consumer gauge. Seeing pressure where there is flow versus pressure at the capped end of a hose is identical. Pressure and flow are two totally different things and one does not influence the other. Pressure is actually caused by restricting or resisting flow.

[dsfra]

Originally Posted by 1engineer

I'm not telling you not to do this (I don't care, although an idiot light will do the exact same thing as what you are trying to accomplish) but you need to understand a few things: Pressure in one part of the system is the same as pressure in the other part of the system, regardless of location. Unless you have different circuits, valves or orifices then the value won't change, at least not enough to pick up on a consumer gauge. Seeing pressure where there is flow versus pressure at the capped end of a hose is identical. Pressure and flow are two totally different things and one does not influence the other. Pressure is actually caused by restricting or resisting flow.

According to AllData, the pressure idiot light doesn't come on till it's dropped to somewhere between 0 and 4.3 PSI, and at that point IMO it's a little too late. For me, Elvis has already left the building. I recognize that pressure is uniform throughout a closed unrestricted system - I was talking about temperature. I'm not much of a thermodynamicsist, but I think that for temperature it would matter. Limiting case: a really really really really long hose with lots of stagnant oil in it would be real real real slow to have the oil trapped at the dead end warm up and reflect the temperature of the oil flowing by at the "hot" end of the hose.

Anyhow, it's always fun to watch what gauges do under different conditions.

[1engineer]

Originally Posted by dsfra

According to AllData, the pressure idiot light doesn't come on till it's <= 4.3 PSI, and at that point IMO it's a little too late. For me, Elvis has already left the building. I recognize that pressure is uniform throughout a closed unrestricted system - I was talking about temperature. I'm not much of a thermodynamicsist, but I think that for temperature it would matter. Limiting case: a really really really really long hose with lots of stagnant oil in it would be real real real slow to have the oil trapped at the dead end warm up and reflect the temperature of the oil flowing by at the "hot" end of the hose.

Anyhow, it's always fun to watch what gauges do under different conditions.

Synthetic oil. Has a great viscosity index. Won't hardly move a gauge from cold to hot. I understand it's fun to watch gauges but in this case it will go to a pressure.... and stay there. It's not like it will go to a pressure and gradually decline if you are having a problem. It will just drop, just like turning on a light.

Lastly on a really, really long hose scenario:
If we are going to run a really really long hose we run pipe or tubing. Why? Because, even though the fluid is basically incompressible (2% at 5000 psi) the hose will expand enough over its length to act as an accumulator and THEN you will have different pressure readings lol. Short hoses, long pipes. That's the rule.

[amalik]

You are worried about a 5th gen 4runner oil pump dying after 60,000 miles? A bit odd to me.

I guess we can't rule anything *out*, especially with the weird issues 5th genners report on here, but at the same time -- I think you're being OCD for no reason. There's a 4th gen that just hit 400k, the member posted the video up in the 4th gen section and he's on factory drivetrain.

I'm not saying you should never worry about this, but too early IMO.

[dsfra]

Originally Posted by 1engineer

Synthetic oil. Has a great viscosity index. Won't hardly move a gauge from cold to hot. I understand it's fun to watch gauges but in this case it will go to a pressure.... and stay there. It's not like it will go to a pressure and gradually decline if you are having a problem. It will just drop, just like turning on a light.

Lastly on a really, really long hose scenario:
If we are going to run a really really long hose we run pipe or tubing. Why? Because, even though the fluid is basically incompressible (2% at 5000 psi) the hose will expand enough over its length to act as an accumulator and THEN you will have different pressure readings lol. Short hoses, long pipes. That's the rule.

Again, I'm talking here specifically about oil temperature, not pressure. In the limiting case example, just replace "hose" with "non-deformable tubular pressure vessel". I used "hose" cuz it's easier to type than "non-deformable tubular pressure vessel", and I'm a lousy typist ;-).

[Edit] I got a "Like" from 1engineer. He likes me, he really likes me!

[dsfra]

Originally Posted by amalik

You are worried about a 5th gen 4runner oil pump dying after 60,000 miles? A bit odd to me.

I guess we can't rule anything *out*, especially with the weird issues 5th genners report on here, but at the same time -- I think you're being OCD for no reason. There's a 4th gen that just hit 400k, the member posted the video up in the 4th gen section and he's on factory drivetrain.

I'm not saying you should never worry about this, but too early IMO.

I was just saying that I'm almost out of the 5 year / 60,000 mile warranty, so now I can do stuff to the engine - like installing real gauges - and not worry about Toyota trying to weasel out of warranty coverage cuz the problem was caused by an "owner-installed modification". No question about Toyota's sterling reliability reputation. Just want see what's going on with the engine, and am more concerned about spotting a potential problem earlier rather than later - cracked or leaking plastic oil filter cap, bad seal or gasket, whatever. Kinda like going to the doc for a check-up.

And BTW, I have lots of reasons for being OCD - just ask my wife...

[philsey]

Originally Posted by 1engineer

.... Pressure and flow are two totally different things and one does not influence the other.

This is true. Anymore I have plenty of the former, and not so much of the latter. Sigh.

[amalik]

Oil temp? Hmm. Never heard of anyone tracking that. Oil pressure yes, not oil temp.

Sent from my LGMS428 using Tapatalk

[dsfra]

Originally Posted by amalik

Oil temp? Hmm. Never heard of anyone tracking that. Oil pressure yes, not oil temp.

Sent from my LGMS428 using Tapatalk

Prolly a remnant from my mis-spent youth wrenching on race cars. But that was then, and blah, blah, blah... We used to even monitor differential temperatures.

[(none)]

This entire thread makes no sense. First you start off talking about oil pressure. Then you talk about removing the oil pressure switch and coolant flowing out. Then you say you are looking for oil temp.

If you want oil temp? They make drain plugs with sensors to replace the drain plug in your pan. That's by far the easiest way to get a good reading. I'd also bet that toyota probably already tracks engine oil temp somewhere (usually there is a sensor by the oil filter/cooler area.

If you are looking for oil pressure, go find that switch for the idiot light and add a tee like you mentioned. I encourage you to do it and post some results, i'd much rather have the gauges than lights.

[dsfra]

Originally Posted by (none)

This entire thread makes no sense. First you start off talking about oil pressure. Then you talk about removing the oil pressure switch and coolant flowing out. Then you say you are looking for oil temp.

If you want oil temp? They make drain plugs with sensors to replace the drain plug in your pan. That's by far the easiest way to get a good reading. I'd also bet that toyota probably already tracks engine oil temp somewhere (usually there is a sensor by the oil filter/cooler area.

If you are looking for oil pressure, go find that switch for the idiot light and add a tee like you mentioned. I encourage you to do it and post some results, i'd much rather have the gauges than lights.

Yeah - brain fade - sorry for the (my) confusion - meant to talk about "oil", not "coolant", flowing out. Damn keyboard - I typed "oil" but it came out "coolant". Thanks for being my proof-reader.

Two separate topics, ergo two separate paragraphs in the original post: First pressure, Second temperature. As far as I can tell, Toyota doesn't make oil pressure or temperature available on the bus - if they did I would be looking at the values on my ScanGauge, and avoid this whole thing. Might look around for the drain plug / temperature sender combo. Anybody happen to know where they're available?

[catrains]

Toyota only has a oil switch this is also used on other vehicles so when you smash up in accident the fuel pump will shutdown.

with this Toyota oil switch it is not gonna help if your low on oil .

oil pressure gauge is good to see how well the flow/wear of the oil and bearings. never seen an oil temp gauge but no problem to do that.

on some engines I have seen these oil sensors/switches in very tight spots could be a problem installing a brass T fitting so you have both the switch and the oil temp/pressure.

buy the Toyota oil pressure switch then see what thread is used probably some odd ball metric , that can be the PITA part.

[dsfra]

Originally Posted by catrains

Toyota only has a oil switch this is also used on other vehicles so when you smash up in accident the fuel pump will shutdown.

with this Toyota oil switch it is not gonna help if your low on oil .

oil pressure gauge is good to see how well the flow/wear of the oil and bearings. never seen an oil temp gauge but no problem to do that.

on some engines I have seen these oil sensors/switches in very tight spots could be a problem installing a brass T fitting so you have both the switch and the oil temp/pressure.

buy the Toyota oil pressure switch then see what thread is used probably some odd ball metric , that can be the PITA part.

What I did was...

I didn't want to pull out the oil pressure idiot light switch just in order to have it available while shopping around for an appropriate sender and/or adapter - thereby disabling the vehicle - then have to re-install it while waiting for the sender and/or adapter to show up. I needed a switch in hand so I could see the threads, then I would know what I needed in terms of threads on the gauge sender and/or adapter. Saw one at Toyota, but they said I wouldn't be able to return it. Since I wouldn't need it once the gauge sender had been installed, and I didn't want to pay $60 for something I wouldn't need and couldn't return, I went to O'Reilly's and picked one up for $13, and they said I could return it if I didn't install it. For confirmation, went to AutoZone, got my hands on one, held it up in profile against the one from O'Reilly's - same diameter threads, same taper, same threads per inch. Went back to Toyota, asked to see their switch. Held it up in profile against the one from O'Reilly's: same diameter threads, same taper, same threads per inch. So now I have a thread sample to use while looking around for a sender and/or adapter, and the vehicle is not out of commission. The long way from A to B, but saved a few bucks. The Toyota parts guy was less than happy with me.

[BlackWorksInc]

The problem is that you don't have a specification for what oil temperature should be and what would be "ideal," thus monitoring it is rather pointless because you couldn't tell what's "within ideal operating range" and what's "slightly hot."

Granted there'd be some general overlap among various engines in terms of temperatures, but without a specific dataset your additional data would be basically for show and nothing else.