How to set up an oil temp sensor reading from the pan?

[GUNDAN323]

Hi,

I am planning on getting a baffle installed on my oil pan soon. While that work is getting done, I was thinking about how to set up an oil temp sensor to read from the oil pan as recommended by many here?

Should I get a 1/8 NPT bung welded on the side of the pan between the baffle and the bottom?

Or maybe use an adapter that replaces the oil drain plug? My concern about this method is that it will hang a little low and may be damaged during off road excursions resulting to a loss of oil.

Your guidance would be greatly appreciated.

Thanks,
Dan

 

[greenberet]

Here's what I did: http://www.nsxprime.com/forum/showt...sensor-where?p=1040867&viewfull=1#post1040867

It's probably been about a decade since I put an oil temperature sensor there, it hasn't needed to be removed once, and it hasn't leaked a drop of oil.

 

[illwillem]

The pan is the best spot. Weld the bung on the lower pass side of the pan so its horizontal to the ground as close to the bottom as you can get it. If you dont wanna bung the pan you can also run one in a T from the oil pressure sensor on the OEM cooler block (the thing that the oil filter is screwed into) I forget the pitch but theres plenty of adaptors out there for this very reason. The oil pressor sensor is basically an on/off sensor that turns on when under 3psi. It isn't looped into any other part of the NSX harness other than giving it 12v switched power and ground and nothing in the ECU is looking for its signal, its purely a stand alone for the oil light on the instrument cluster.

If you have a external after-market oil pressure already I would suggest not teeing to that port and just not running the oil pressure light directly too the hole since T fittings have been know to not really give accurate readings since its only exposed to oil thats trapped in the T fitting itself. Idealy you do the pan bung, second you'd do something like the SOS sandwich plate thirdly and free you can hijack the OEM pressure switch port.

I wouldnt really do a tapped oil pan bolt. If you drill and tap to fit a 1/8npt port you are only left with about a third of the actual oil drain bolt in the end. im guessing this has has something to do with why ive seen more than one work itsself out under hard driving.

 

[GUNDAN323]

Thanks for the input.

I will weld a 1/8 NPT steel bung on the lower pass side of the pan.

 

[greenberet]

I wouldnt really do a tapped oil pan bolt. If you drill and tap to fit a 1/8npt port you are only left with about a third of the actual oil drain bolt in the end.

I agree that tapping threads into the oil PAN drain bolt doesn't sound like a good idea.

For the sake of clarity, I tapped threads into the oil PUMP drain bolt. If you didn't know the oil pump has a drain bolt – neither did I until I saw that big, 1" bolt above the oil pan and researched what it is. The service manual doesn't show it ever being removed, not even during an oil pump overhaul. Furthermore, that bolt is completely and safely out of the way, there's engine oil right behind it, and you only need to remove about 5-10% of its mass to mount a temperature sensor in there.

I'm sure welding a bung into and repainting the oil pan is another good solution. It just seems like more work to mount the temperature sensor in a more exposed location and to a part that might need to get replaced in the future if it gets dented or such. I'd still rather do that than simply screw a temperature sensor into the oil pan drain plug, though.

 

[GUNDAN323]

Should the oil pan be refinished with any particular coating?

For the inside, I was thinking of just leaving the current finish, but roughing up the spots where the baffle is welded in. So those spots inside would be scuffed up with no coating, but the oil would prevent corrosion.

For the outside, the welding around the bung will need protection I think. I was thinking of just spraying a little of high temp paint from Autozone in the newly exposed bung area . I also plan to wrap the pan with gold reflective foil to fend off radiating heat from the front bank headers.

 

[RYU]

I have my oil pressure sensor and oil temp sensor in the outlet and inlet of my side mount oil cooler. I used the SOS sandwich plate for ease of install and reversibility. I have heard that the oil pump bolt location is the best spot but install seems more involved so I decided against it. I also don't like things hanging off my oil pan like a bung or a sensor so I didn't go the oil pan route either. More importantly, I knew I didn't have the luxury of removing the pan > taking it to someone > install/weld the bung > install/weld the baffle > install the oil pan on the motor several days/weeks later > deal with potential leaks from the bung welds and start all over again. I went to my mechanic armed with my sander and mig welder in the trunk. I brought a ton of brake cleaner and welded in the STMPO oil pan myself in 30 mins. The oil pan is thin so you have spot weld it with relatively low heat. I didn't do such a great job on a couple of spot welds and it burned thru the paint on the other side. No leaks! I covered it with Gold Leaf and since this pic was taken the headers are now ceramic coated inside and out.

- - - Updated - - -

I did not paint the inside of the oil pan post weld. I didn't feel I needed to because the chances of rust was low. I also considered that most high heat paint was not designed for prolonged submersion to hot oil. The paint might just flake off and swim around in my engine.

 

[jaffaz32]

These are a cheap alternative for a oil feed for a sensor but it's not that pan as you mentioned.

http://www.scienceofspeed.com/produ...cts/NSX/ScienceofSpeed/feed_pressure_adaptor/

 

[illwillem]

^ that is the thread pitch that will work on the oil presser sender too, Though I wouldnt read anything tempature related up on the heads it will be significantly different that in the pan. The oil gear bolt is a great idea too.
You can spray the inside of the pan to cover the welds if its enamel, I wouldnt though. it wont rust if its submerged in oil. id only re spray the outside with some BBQ or high-temp paint. Be careful welding the pan though. the heat that will be concentrated in that one area can very easly warp the thin steel pan, even ever so slightly and it will never seal right again. Its always a good idea to check the pan post welding on a leveling table. Its hard to find people that have them but Ive got a friend that has one at work if you need.