E36 coolant temp sensor in LS1

[BRAAP]

exactly!

Now I just have to figure out what to do for the VDO gauge that I have inplace of the OBC.

Does the VDO gauge have its own sender? If so, you could drill and tap a hole in the cylinder head to accept that third sender.

[Pzary3233]

yeah it does, but I hate the idea of drilling and tapping into a pair of LS6 heads... May let the machine shop do that one.

[boriksh]

Another option is to use adapter. I believe this is what you might need. Perhaps you can contact them to make sure: Click Here For Adapter

so just to verify, if i have 95- car, this is the adapter that i need?

[Pzary3233]

NO!

Water Temperature Sending Unit Adapter
Part # BMW-127. Shipping weight, 1 lb

Using the BMW water temperature sending unit in the Chevrolet engine will make the BMW water temperature gauge read accurately.

The BMW water temperature sending unit has a 14mm x 1.5 thread. Stealth Conversions has a brass adapter (shown above) that accepts the BMW water temperature sending unit, and has a 3/8 pipe thread (NPT) that screws into the Chevrolet heads or intake manifold. If you have an older engine which has 1/2 pipe fittings, a 1/2 to 3/8 brass bushing can be obtained at most plumbing or automotive stores.

It needs to be an M12 to M14 adapter.... or mill down the 95 sensor to fit in the 12x1.5mm hole... Ask 375i

[M5Hunter]

NO!



It needs to be an M10 to M12 adapter.... or mill down the 95 sensor to fit in the 10mm hole...

This is also incorrect, the hole in the LSx head is a m12x1.5

The pre '96 bmw coolant temp sensor for the gauge is a m14.

To make that sensor work, you will either have to find a m14 to m12 adapter(good luck!!) or mill down the sensor threads and re-thread it to to m12x1.5 like I did.

[Pzary3233]

Woops sorry I had a differen sensor in my mind! Edited post

[BRAAP]

This is also incorrect, the hole in the LSx head is a m12x1.5

The pre '96 bmw coolant temp sensor for the gauge is a m14.

To make that sensor work, you will either have to find a m14 to m12 adapter(good luck!!) or mill down the sensor threads and re-thread it to to m12x1.5 like I did.

...Or purchase a 14mm tap and corresponding drill bit then open up and tap the threaded hole in the LSx to accept the 14mm sensor. ;-) Probably cheaper and faster than sourcing a specific 12mm to 14mm fitting.

...Edit...
Of if you already have a 3/8 NPT tap, you could use the JTR adapter linked below that specifically fits the early BMW temp sender.

http://www.jagsthatrun.com/Pages/Par...mpSending.html

[Pzary3233]

Ok so there are X number of ways to go about this:

*Of if you already have a 3/8 NPT tap, you could use the JTR adapter linked below that specifically fits the early BMW temp sender.
http://www.jagsthatrun.com/Pages/Par...mpSending.html

*purchase a 14mm tap and corresponding drill bit then open up and tap the threaded hole in the LSx to accept the 14mm sensor. ;-) Probably cheaper and faster than sourcing a specific 12mm to 14mm fitting.

*Mill down the sensor threads and re-thread it to to m12x1.5 like I did.

*It does look like the '96 and newer snesor will work, but it has a 4 prong connector rather than the 2. You can use this sensor but it will give a false reading.

Lets collaborate and make sure we have the information CORRECT.

[M5Hunter]

That looks right

[Pzary3233]

Ok I am going to add it to the Wiki

Maybe Quote it in your first post so there isn't any searching needed?

[Maynor]

For reference:

12 mm x 1.5 mm GM LS1 sensor on the right. 12 mm x 1.5mm 96+ BMW sensor (95% certain) on the left, with an epoxied two wire pigtail to fit a stock 93 318i dash water temp gauge plug. Both are out of my LS2 engine'd E36. The BMW sensor is for sale if anyone is interested.



You can see the differences in length (marginal) but the BMW sensor plugs right into the stock heads on an LSx head without any modifications necessary. It also reads correctly on the stock water temp gauge.

I moved onto a dedicated electronic water temp gauge and disconnected the dash gauge entirely.

John
E36 LS2

[BRAAP]

Does anyone have any evidence to support the early vs late gauge temp senders ohm curve being different?

If not lets put it to bed. Someone post the ohm readings of their early sensor at 60 degrees F and 200 degrees F. Use a pan of water for both measurements, verify water temps are stable during readings, allow the sender to stabilize before taking reading, do not let the temp sender to rest on the bottom of the pan during the heat portion as the burner will influence. Only submerge the sender up to the top of the threads to keep consistency with these measurements.
Here are the readings from my '97 M3 4 prong sender for the gauge.

Temp gauge pictured was checked for accuracy against an infra-red temp gun and Fluke Temp probe, dial was within 3% at 60 and 200. Overall all temp vs ohm readings should be in the neighborhood of +/- 10%.

4 prong BMW temp sender-gauge.
http://www.pelicanparts.com/cgi-bin/...3%20B%33%32%20

60 degrees F = approx 8000 ohms.
200 degrees F = approx 500 ohms.

[Maynor]

Good test but is it really critical they be exact?

The BMW temp display is a dummy gauge anyway isn't it? 3 modes: "Off - You have heat - You're overheated" modes no? The gauge doesn't fluctuate according to temp. from my experiences so far.

Its mostly a "hey, you're overheated" only type of gauge like most OEM's do For that purpose. slight variation in the resistance curve, assuming any exists, won't really matter.

Or is that not accurate for all model years?

[Pzary3233]

I am not sure, but I want it to be as accurate as possible...

I still will have an aftermarket gauge, but it would be nice to use the idiot gauge as a quick check.

[BRAAP]

Good test but is it really critical they be exact?

Exact? No it doesn't need to be exact but it does need to be close if you want your gauge to read with any sort of accuracy.

..

The BMW temp display is a dummy gauge anyway isn't it? 3 modes: "Off - You have heat - You're overheated" modes no? The gauge doesn't fluctuate according to temp. from my experiences so far.

Its mostly a "hey, you're overheated" only type of gauge like most OEM's do For that purpose. slight variation in the resistance curve, assuming any exists, won't really matter.

That would be a wrong assumption. What you are describing is a properly function cooling system, the gauge is merely in indicator of that. Here is a quick and dirty explanation of the temp gauge and sender.
The gauge is an analog display of the coolant temp. The resistance of the sender tells the gauge where to point. As the engine warms up, the needle on the temp gauge rises. If the thermostat is doing its job and the coolant level is full and the radiator is doing its job, the engine temp gauge will rise to approx. mid point and remain, possibly fluctuating a skosch either way, remaining mostly stable. If something goes awry, thermostat sticks, loss of coolant, radiator plugged, etc, then the temp gauge will crawl up as the engine gets hotter, "indicating" to hopefully an alert nut behind the wheel, that something is wrong with the cooling system and appropriate action needs to be taken.
Now if the resistance values of the sender are off by more than 10% or so to what the gauge is calibrated for, it will read inaccurately, high or low depending on if the values are high or low. As such it is important that the values be close. +/- 5-10% is not that big of deal. As you suggested, the temp gauge is for reference, not a precision instrument, but its sender should be close in resistance values to what it was designed for.

Back in the old days temp warning was merely an idiot light and a switch. Engine gets hot enough to to match the switches preset temp threshold, switch goes on illuminating the HOT light. Engine cold, switch open, no light. You had no way to know if the engine was colder or hotter than normal. Personally, I prefer a gauge and a light. Light is to get the drivers attention, gauge to indicate the severity of the condition.


Hope that helps explain the function and purpose of the temp gauge as used in all cars.

[Maynor]

I understand all that. That's what a dash based temp gauge SHOULD do. But I know for certain, that's not what they ALL do. Ford for example, except for the gas gauge/speedo/tach, most of the later model cars dash gauges are idiot gauges. They never move in relation to real-time sensor change except in the fashion I spoke about.

GM's gauges are mostly real and actually have temp figures demarcated with moving needles as the sensor gives real-time feedback.

Ford and BMW do not demarcate their gauges. My experience with the E36 gauges, on track (its a track only car so lots of high rpm, full load driving), is it doesn't move unless there is "No heat, Heat or Over heated" situation.

Hence the original question. I may not be right and my car my be unique so YMMV. The lack of numerical demarcation and the behavior I observed on track is what led me to that presumption.. and presumptions are meant to be broken.

Anyone know if the gauge is an idiot gauge or real? I also agree, I prefer a gauge with a warning light... which is what I switched to for peace of mind.

John

[Schitzo]

Maynor you are correct, some gauges do that. For example for my E39 I had to get a separate VDO temp gauge because the stock E39 gauge is a dummy gauge. When warmed up, it moves to the mid position and never moves unless the engine overheats or cools down. Thats unacceptable for me.

[Pzary3233]

Brrrrraaaaaaaaaappppppp - (Where did you come up with that user name? lol)

Can I send you an OBD I sensor and have you test it so we have concrete data keeping all other variables the same? ie test instruments etc.

That way we can map a curve and get this resolved for good.

Another Paul

[BRAAP]

I understand all that. That's what a dash based temp gauge SHOULD do. But I know for certain, that's not what they ALL do. Ford for example, except for the gas gauge/speedo/tach, most of the later model cars dash gauges are idiot gauges. They never move in relation to real-time sensor change except in the fashion I spoke about.

GM's gauges are mostly real and actually have temp figures demarcated with moving needles as the sensor gives real-time feedback.

Ford and BMW do not demarcate their gauges. My experience with the E36 gauges, on track (its a track only car so lots of high rpm, full load driving), is it doesn't move unless there is "No heat, Heat or Over heated" situation.

Hence the original question. I may not be right and my car my be unique so YMMV. The lack of numerical demarcation and the behavior I observed on track is what led me to that presumption.. and presumptions are meant to be broken.

Anyone know if the gauge is an idiot gauge or real? I also agree, I prefer a gauge with a warning light... which is what I switched to for peace of mind.

John

Maynor you are correct, some gauges do that. For example for my E39 I had to get a separate VDO temp gauge because the stock E39 gauge is a dummy gauge. When warmed up, it moves to the mid position and never moves unless the engine overheats or cools down. Thats unacceptable for me.

Hmmm… Interesting, in all my years building and racing sports car, I have not run across this style of temp gauge, (we mostly cater to the old Datsun Z cars, Rusch Motorposrts LLC), nor do I like the sounds of it. One thing I have learned since I started in the high performance sports car industry is regarding any OE gauges, whether it is temp or oil pressure, numbers on the face does not indicate a gauge is calibrated with any sort of accuracy vs another gauge that doesn’t have any numbers/figure/demarcates, one just has numbers that "loosely" represent the figures depicted, either one is really no more or less accurate than the other and could be calibrated to indicate more accurately if one takes the time to mess with the gauge, needle, tik marks, etc. This 3 step indicator thing is as step blow the idiot light! The idiot light at least glows to get the drivers attention!

Brrrrraaaaaaaaaappppppp - (Where did you come up with that user name? lol)

Can I send you an OBD I sensor and have you test it so we have concrete data keeping all other variables the same? ie test instruments etc.

That way we can map a curve and get this resolved for good.

Another Paul

Sure thing. I'll PM you the shipping address.

BRAAP came from the local sports car club I Auto-Cross with since the late ‘80’s. My first Datsun Z with the inline 6 had an incredible exhaust note, club called the car BRAAP due to its exhaust note. The name stuck, I was young and stupid then, bought vanity plate, use it only the track cars now.
One of many Z cars I have had over the years…

BRAAAP… BRAAAAAAAAP….. BRAAAaaaaaaaaaa………….

[Schitzo]

This 3 step indicator thing is as step below the idiot light!

Couldn't have said it better.



by the way sweet Z

[M5Hunter]

I will agree that the late model fords(04+) trucks have "dummy" gauges. There is a range that puts the needle right in the middle of the "normal" zone, when it ecceeds that range, it jumps to the red

[BRAAP]

I will agree that the late model fords(04+) trucks have "dummy" gauges. There is a range that puts the needle right in the middle of the "normal" zone, when it ecceeds that range, it jumps to the red

Soooo friggin retarded and pointless.

Now where did I set my Rogue Brewery, Dead Guy Ale? ...

[mateo m3]

wow crazy looking z!!!!

[Maynor]

I love the old Z cars. Nice niche to focus on Braap! You know one car pic isn't going to be enough... post another thread with a selection of cars please. And you're right, idiot gauges are a step of below a simple warning light which will catch you're attention..

[bimerok]

For reference:

12 mm x 1.5 mm GM LS1 sensor on the right. 12 mm x 1.5mm 96+ BMW sensor (95% certain) on the left, with an epoxied two wire pigtail to fit a stock 93 318i dash water temp gauge plug. Both are out of my LS2 engine'd E36. The BMW sensor is for sale if anyone is interested.



You can see the differences in length (marginal) but the BMW sensor plugs right into the stock heads on an LSx head without any modifications necessary. It also reads correctly on the stock water temp gauge.

I moved onto a dedicated electronic water temp gauge and disconnected the dash gauge entirely.

John
E36 LS2

Not sure if that is BMW e36 96+ sensor as they have round connectors. Here is the pic of my 96+ sensor