E36 coolant temp sensor in LS1

[Maynor]

That picture is a little deceptive. Its a round plug but the angle really doesn't show it.

[BRAAP]

Guys,
Don't take this wrong but, why do you guys keep adding confusion to things that are not confusing? (that was a rhetorical question, please don't answer it).

Bimerocks new sensor is the later "round" 4 prong sensor, 12mm threads, the same exact one that I tested a couple posts back. It is NOT the same as the early square shaped Bosch style connector, temp sensor that Maynor pictured.

What is unknown right now is the ohm to temp values of the early square sensor.

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

Raaaaoooooo......

[mateo m3]

lol i love this place.

[RahgBag]

I didn't read the entire thread, but can't you just use something like this to use the early e36 sensor with the smaller LS1 hole?

http://www.muepro.com/index.php?id=10321

[M5Hunter]

you could, but you'll notice there is no m12 to m14 listed, they are basicly non-existant

[Pzary3233]

Braap,

very nice Z car! There is a 280 XP car in our region with a VQ35 swap. Very cool car.

Anyways, I was not able to get the sensor out to you on friday, so I should get it sent via UPS to you tomorrow!

[BRAAP]

Braap,

very nice Z car! There is a 280 XP car in our region with a VQ35 swap. Very cool car.

Anyways, I was not able to get the sensor out to you on friday, so I should get it sent via UPS to you tomorrow!

By chance would that VQ powered Z by a gorgeous Metallic Dark Blue with Carbon Fiber hood, black flares?

No problem on the temp sender. Don't forget to include the address you me to return it to.
I also ran a couple other senders/sensors through the same test and logged them all at 60, 70, 100, 160 and 200 degrees F, entered them in a spreadsheet that shows their resistance curve against each other in a line graph, I'll post that after I get yours and plot it out as well.

[Pzary3233]

By chance would that VQ powered Z by a gorgeous Metallic Dark Blue with Carbon Fiber hood, black flares?

No problem on the temp sender. Don't forget to include the address you me to return it to.
I also ran a couple other senders/sensors through the same test and logged them all at 60, 70, 100, 160 and 200 degrees F, entered them in a spreadsheet that shows their resistance curve against each other in a line graph, I'll post that after I get yours and plot it out as well.

Paul,

No, this one is a red one, lexan, glass, etc, etc, etc.



That's the only picture I could find of it... Going to Chicago to get the Autronic Standalone wired - this was their first VQ.

Here is his build thread: http://midsouthscca.org/PNphpBB2-vie...order-asc.html

While on the subject of Z cars... I LOOOVE this one:

http://www.reactionresearch.com/280yzgallery.html

That's the Darius Z guy that has built some wild cars.

Anyways, back to the subject at hand, I'm including both the DME and Cluster sensor so we can verify they are the same.

Paul

[BRAAP]

Don't know the Red, one. Quite familiar with Darius's Z (and his other combustion engine powered toys), he's a member on our HybridZ forum.

Yeah, were getting too far off topic, sorry guys.


I'll post the results of both sender and sensor when they arrive.

[Pzary3233]

Maybe we just need a Conversion Forum chat thread... heh...

Anyways, sending units SHOULD be to you Wednesday or Thursday.

[RahgBag]

you could, but you'll notice there is no m12 to m14 listed, they are basicly non-existant

Whoops...I thought it was a M12 to M10 reducer we were looking for.

[Pzary3233]

^ Sorry that was my fault, I had a brain fart and posted the wrong sizes.

-Paul

[RahgBag]

It's a M14 to M12 with 1.5 thread pitch we need, right? I haven't actually looked at mine yet, spent all day on other stuff.

In which case, would this work?

http://www.amazon.com/Spark-Plug-Thr.../dp/B000J4K0AM

[BRAAP]

Update!
First off, thank you to Pzary for his help.

Water temp sendors AND sensors, BMW EFI, BMW Gauge and LSx, measured, (Senders and sensors tested were BMW BOSCH connection/square 2 prong; Black top, Green Top, Brown/Tan top, 4 prong prong round top, early Datsun EFI and GM LSx. Of interesting note is that all the BMW 2 prong EFI and Datsun EFI sensors were within 2% of each tother from 60-20 degrees F).

First the good news.
The resistance values-vs-temp values for the instrument gauges on ALL E36 cars, '92-'99 are the same! We all have been speculating they were different, come to find out they aren’t. BMW originally utilized two separate sensors/senders, (one for the EFI, other for the gauge), on the ’92-’95 cars then in ‘96 combined them into one housing for the later cars, the 4 prong sensor/sender and retained the same exact values for both DME and gauge.

Now the great news!
What that means for anyone doing the 92-’99 E36, (318, 323, 325, 328, M3,) LSx conversion is the ’96+ 4 prong sensor/sender works with their gauge and threads directly into the LSx head, no drilling, tapping, bushings, adapters etc to use the earlier 2 prong sensor, unless you want to. Just deduce which 2 prongs for the gauge, (easy to do with the Bentley manual and an OHM meter), and you’re there.

As for the pig tail, many other BMW’s used this same connector, easy to find in wrecking yards on other cars.

The just ho-hum news.
The LSx PCM sensor has a slightly different curve/slope compared the BMW EFI temps sensor, enough so that you wont want to use the BMW DME sensor for the LSx PCM, (see chart below). One could possibly adjust the CLT values using one of the tuning suites, I am pretty sure it’s just easier to install the GM temps sensor in the other head and be done with it. For what it’s worth, ALL GM temp sensors coolant and air temp have the same resistance to temp values, across the board, Pontiac, Olds, Chevrolet, etc, applicable to all GM Multi Port EFI vehicles.


LEGEND!
X axis= Degrees Fahrenheit.
Y axis = resistance in OHMS.
BMW EFI I = OBD-I DME temp sensor.
BMW EFI II = OBD-II DME temp sensor.
BMW Gge I = OBD-I gauge temp sender.
BMW Gge II = OBD-II gauge temp sender.
LSx EFI = PCM temp sensor.




As mentioned earlier, There is a down side to these BMW temp gauges. I spent a bit of time researching this and here is what I found.
BMW incorporated some form of buffer within the instrument cluster itself that holds the temp needle straight up, middle of the gauge when the engine is between 140-230ish degrees F. If the coolant temp breaches 230-ish then the gauge will swing from the middle up to HOT, not an incremental climb as one would expect or hope for as the engine gets warmer. The sender itself is analog like any other sender for a temp gauge, this buffering is done in the instrument cluster. Some feel the Euro cluster has less of a buffer but I was not able to find any evidence to support or deny that claim. There is a bit of speculation as to why BMW did this, turning a perfectly useful analog gauge into useless cold hot dial, beneficial no one. (theories such a people are getting so stupid that when they wee gauge move from center they panic and take their car to the dealer so this prevents unnecessary warranty claims, etc). Regardless, I see no point in trying to figure out why BMW did this, it is what it is, any discussion should really be centered around a possible solution to obtain a true analog temp gauge. Some have talked about trying to remove the buffer in the instrument itself, others have successfully replaced the internal guts of the temp gauge with VDO guts, stock needle and now have a gauge that indicates temperature on an analog scale. If someone finds a way to eliminate the buffer itself or other way so to get around this, please share, for now, here is what I found;


The issue, for those interested in reading;
http://forums.bimmerforums.com/forum....php?t=1208832

http://forums.bimmerforums.com/forum....php?t=1480682

http://m3forum.net/m3forum/showthread.php?t=324399

Fixes;
http://forums.bimmerforums.com/forum....php?t=1105631

http://forums.bimmerforums.com/forum...d.php?t=776813


Hope this helps someone.

[M5Hunter]

Now thats dedication.
All good info, thanks for takking the time to break it down

[Pzary3233]

Awesome Paul!

Just plain AWESOME!!!

So now you just need to get your Euro Cluster to test, or I can try to get mine out at some point and send it to you for testing.

357I can you edit your post with a quote of Braap?

[RahgBag]

Wow, great work. I'll be ordering a new style gauge and pigtail adapter asap.

[bimerok]

Here are the pins to use (Looking at the connector's end. X20 pins based on 1996 328is):


Connector Part # 12521703571 - Need One
Connector Pins # 61130007657 - Need Two (usually comes with short wire and seal)

[rao]

Oh wait, I was right all along, who would have guessed

[BRAAP]

For those doing LSx conversions in other BMW cars, here is a list of BMWs that use the same temp-resistance value sensors as the four prong BMW sensor that fits the LSx head therefore works for these cars temp gauges, (not that anyone with a Z8 would perform such a swap)

E31 8-series;
840i/Ci ’94-’97 M60/62
850Ci, ’91-’97 M70/73
850 CSi, ’94-’95 S70


E32 7-series;
735i/iL, ’88-’92 M30
740i/iL, ’93-’94 M60
750iL, ’88-’94 M70


E34 5-series;
525i, ’89-’95, M20/50
530i, ’93-’95 M60
535i, ’89-’93 M30
540i, ’93-’95 M60
M5, ’91-’93 S38


E36 3 series;
318i/is/ti, ’92-’999 M42/44
323i, ’98-’99 M52
325i/is, ’92-’95 M50
328i, ’96-’99 M52
M3, ’95-99 S50/52

E36/7/8 Z series;
Z3, ’96-’03 M44/52/54/S52


E38 7-series;
740i/iL, ’95-’01 M60/62
750iL, ’95-’01 M73/N


E39 5 series;
525i, ’01-’03 M54
528i, ’97-’00 M52
530i, ’01-’03 M54
540i, ’97-03 M62
M5, ’00-’03 S52


E52, Z series;
Z8/Alpina V8, ’99-‘03 M62/S62


E53 5 series Sport-ute;
X5 3.0i/4.4i/4.6is/4.8i ’00-’06 M54/62N62







Ps.
I did try a single pin gauge temp sender from an ’88 E28 5 series, values are totally different, much lower resistance values.

[Thaniel]

As mentioned earlier, There is a down side to these BMW temp gauges. I spent a bit of time researching this and here is what I found.
BMW incorporated some form of buffer within the instrument cluster itself that holds the temp needle straight up, middle of the gauge when the engine is between 140-230ish degrees F. If the coolant temp breaches 230-ish then the gauge will swing from the middle up to HOT, not an incremental climb as one would expect or hope for as the engine gets warmer.

From my experience the guage does not appear to work that descretely or binary to me. On my swap I used the BMW EFI sensor an wired it in. Due to the resistance difference which you have documented in detail (thanks) the gauage always reads high. Since I know what the range is I can still keep an eye on things. And it gives me comfort to know it'll light the overheat red light if temps even stray a little above normal operating temps (not anywhere close to overheating temps).

So on my car when the engine is at operating temperature the gauge always reads above center. I've compared against OBDII temp readings from the LS1 temp sender to know how the gauge compares to the real temps. Anyway it does happily set to the side of center. The fans come on at something like 210 and comparing with the EFI sensor that occurs just under the red mark on the temp guage. So between the center and the red mark the guage does float between the two. However if it does cross into the red, lighting the light it does seem to hold it up there until the temp drops well below the red.

Suppose if someone wanted to verify they could connect a variable resister and move it around and see how the needle tracks. How about BRAAP? You seem to be good at collecting data

[BRAAP]

...Suppose if someone wanted to verify they could connect a variable resister and move it around and see how the needle tracks. How about BRAAP? You seem to be good at collecting data

I did try that in my car, no joy.
Using a 0-10k Linear taper POT, (variable resistor) across the two wires from X20, Brn/Yellow pin #11, Brn/Vio pin #12, connected my battery, turned the key to ON, the instrument cluster light up with the bulb check including the overtemp light then went out, but could not get the gauge to budge or the over temp light to light up with the POT. All other wires in X20, X69 and X6031 are currently disconnected. Possibly the instrument cluster may need one or more of those other wires connected before it will read the water temp signal? Haven't got that far with the wiring yet.
Maybe someone else would be willing to try a 0-10k POT on their car, in-place of the gauge water temp sender? How bout it Thaniel?... (If anyone else tries this and is not familiar with electronics, probably a good idea to use a 100 or 200 ohm fixed resistor in series with the POT as protection when testing the hotter range of the gauge.).


Ps. My wife has taken interest in your EV-36 project.

[Thaniel]

Here are the pins to use (Looking at the connector's end. X20 pins based on 1996 328is):

Connector Part # 12521703571 - Need One
Connector Pins # 61130007657 - Need Two (usually comes with short wire and seal)

Need some help here. I ordered the conector an the pins and a 96+ sender (sender # 13 62 1 703 993). The connector fits perfect into the sender. However the pins I recieved are male pins same as whats in the sender. So obviously won't fit together.

From those that have done it did they send me the wrong pins or is the part # 61130007657 not the right one?

Maybe someone else would be willing to try a 0-10k POT on their car, in-place of the gauge water temp sender? How bout it Thaniel?...

Sorry missed your post back. Sure when I go to install the new sender I can try a pot (if I can find one). Thinking I could video tape the guage as I turn the pot to show the lag if any.

Ps. My wife has taken interest in your EV-36 project.

It's a fun little project. I should update my blog. It's horribly out of date. Still no where near finished but I give people joy rides and let them drive it around the neighborhood right now. Hey had a thought. The temp wires on my EV36 are dangling waiting to be attached to something (haven't decided what). I could easily hook them to a pot and test it the next warm dry saturday (no garage at the moment).

Thaniel.

[bimerok]

Need some help here. I ordered the conector an the pins and a 96+ sender (sender # 13 62 1 703 993). The connector fits perfect into the sender. However the pins I recieved are male pins same as whats in the sender. So obviously won't fit together.

From those that have done it did they send me the wrong pins or is the part # 61130007657 not the right one?

Thaniel,
from what I understood, they send out universal pins male/female. You just need to carefully cut the very ends of male and it becomes female. Weird, I know.

[Thaniel]

Thaniel,
from what I understood, they send out universal pins male/female. You just need to carefully cut the very ends of male and it becomes female. Weird, I know.

Ah. Yes weird. I had thought cutting one might get it to work but never thought that was the correct way guess I'll try to cutting them. Thank you for the info.