I think the temperature sensor you have is intended to be plumbed into a coolant hose.
You can put this on your radiator inlet hose:
http://www.autometer.com/cat_accessoriesdetail.aspx?vid=52

All of the head temp adapters I've seen are 1/8" NPT.

Check out Autometer for some adapters, or maybe one of their sending units would work?

http://www.summitracing.com/parts/atm-5284
Auto Meter

Good luck!

Greg

 

I think the temperature sensor you have is intended to be plumbed into a coolant hose.
You can put this on your radiator inlet hose:
Auto Meter

All of the head temp adapters I've seen are 1/8" NPT.

Check out Autometer for some adapters, or maybe one of their units would work?

http://www.summitracing.com/parts/atm-5284
Auto Meter

Good luck!

Greg

This is the temperature sensor I have.

It is designed to screw into anything in the water jacket with a 3/8" NPT thread. I want it in the head for accurate readings so it is similar to the stock coolant temp sensor.

 

Is there any smaller ones available you can use? What is the diameter of the probe?

 

No clue if there are other parts that will work. I know this one is designed to open up and send ground to the relay to tell the fans to kick on. It seems like it is pretty specific to me.

All of the autometer sensors are just that... sensors. They just relay how hot the water temp is. Nothing designed around controlling the relay.

 

racepak sells the temp sensor you seek.

 

Looks like they just have sensors to me. No tstats.

I cut out a small section of radiator hose and put in a small steel exhaust tube coupler with an NPT bung welded in. My rad is in the rear though, so I had plenty of hose to work with. I also have the tube bead rollers to put a clamp bead in the pipe.

Ain't nobody got time fo dat.

The temperature that thing controls to is much lower than what the stock motor would have been. I know 3rd and 4th gen chevys operate at 210 all day long.

I wouldn't overthink the placement of that sensor since it doesn't shut your fans off until the coolant temp is 175F. They'll probably just run all day long after you're up to temp.

Fans kick off 175. Kick on at 195. Which means it will run hotter than 195 so I should be in the ball park.

I'm not over thinking where to put the sensor. I'd like to stick it in the head cause that is where it is supposed to go.

The hose insert thing you posted earlier looks like another option. I really don't want to split a hose though.

EDIT: I was planning to use this thermostat to run the temp gauge on the dash. But now I'm rethinking whether or not that will even work.

 

I cut out a small section of radiator hose and put in a small steel exhaust tube coupler with an NPT bung welded in. My rad is in the rear though, so I had plenty of hose to work with. I also have the tube bead rollers to put a clamp bead in the pipe.

 

You can buy a similar peice from speedway

 

The temperature that thing controls to is much lower than what the stock motor would have been. I know 3rd and 4th gen chevys operate at 210 all day long.

I wouldn't overthink the placement of that sensor since it doesn't shut your fans off until the coolant temp is 175F. They'll probably just run all day long after you're up to temp.

 

Why are you not letting the computer control your fans via relays? I am and it works perfectly, no aftermarket sensors necessary. (The sensor I did on my rig was for a gauge.)

 

I wanted to. But those pin outs were removed from my ECM. I can add them but don't know how the E38 controls the fan.

 

What year, make, model is your ECM? I'll look up the tune file and see what I can tell you if you want ...

I have an E40 ECM, the one right before yours. I think what people may be thinking of is PWM fans vs. discrete? If so, my ECM allows the tuner to select which type you have. There are some tables to edit beyond that to control when you want the fan(s) on and off, but other than that I couldn't tell without looking at your tune.

 

That is correct. People are all over the place on which way it is. I don't know at the moment but I can find out pretty simple.

I've got that engine/ecm and i'm letting the ecm control hi and low fans.... but don't ask me, just hooked up the ground through realys as i was told to do

did u already rule out the heater ports which are usually plugged anyway? thats where I take my water temp. I did have to space it back with a "street" style nipple so i did not crash the probe into the t-stat.

Do you know the thread pitch size for the heater ports? I can do some research on it myself but just thought I'd ask in case you knew.

 

I've got that engine/ecm and i'm letting the ecm control hi and low fans.... but don't ask me, just hooked up the ground through realys as i was told to do

did u already rule out the heater ports which are usually plugged anyway? thats where I take my water temp. I did have to space it back with a "street" style nipple so i did not crash the probe into the t-stat.

 

I would not be scared if drilling and tapping the head if you take your time and use some grease it will get most the shavings out.

But as mentioned the E38 should control it Here is the pin outs E38 ECM Connector Pinouts

 

I would not be scared if drilling and tapping the head if you take your time and use some grease it will get most the shavings out.

But as mentioned the E38 should control it Here is the ok outs E38 ECM Connector Pinouts

typically, one gets tapped to 3/8 pipe and the other 1/2 pipe, easily, in car.

I want to cross this off the list this evening. So if I jack up the head I'm coming over to each of you'alls house shortly after. :flipoff2::laughing:

 

I just looked up 2008 stock tune files for Escalade, Sierra, and H2. They are all discreet fan systems, but have the option to switch to PWM. All the on/off tables are the same as my E40, meaning you can adjust at what temp they turn on and off. I can post screen shots if you like, but I am certain the ECM can control your fans without additional sensors. I adjusted my on-off temps to run the engine just a hair cooler than 210 since I knew I would be throwing a beat down on it. Its never got above 200* no matter what I am doing. I am probably going to go back to stock parameters though now that I've seen how well it controls them.

 

This is my ideal setup. But I can't tune my own setup yet. And I want to drive this bitch this weekend. I found out last night that there are no pin outs for the fan so I scrambled for something different.

 

You can drive it. Just don't do it long.

You could also wire low speed to one fan and high speed to the other and just run it in stock config until you can get it tuned.

If you're worried about whether it is currently in PWM mode or not, just run the engine up to temp with a volt meter on the wires. You'll see when the ECM clicks the relay and if it doesn't, its in PWM mode and yo need a tune. Chances are very low I would say that it is in PWM mode though.

Is this something to where you want to drive for the first time tonight and then put it away or are you wanting to go on a trip tonight? How desperate are you REALLY to drive it tonight?

 

Just checked a Corvette tune. It was in PWM mode. This makes me think that the Corvettes got the PWM fans and the trucks got discreet.

 

This falls in line with what most people say.

You can drive it. Just don't do it long.

You could also wire low speed to one fan and high speed to the other and just run it in stock config until you can get it tuned.

If you're worried about whether it is currently in PWM mode or not, just run the engine up to temp with a volt meter on the wires. You'll see when the ECM clicks the relay and if it doesn't, its in PWM mode and yo need a tune. Chances are very low I would say that it is in PWM mode though.

Is this something to where you want to drive for the first time tonight and then put it away or are you wanting to go on a trip tonight? How desperate are you REALLY to drive it tonight?

I have been driving it in my drive way over the past few days. In.. out... in... out... Now I'm ready to go get a coke. :laughing:

I don't have to drive it on a trip. But it needs to get checked off the list. Tonight is working on the over flow catch can and the fans. Then the cooling is finished. I'm not waiting two more weeks to figure it out. I do have an event I'm planning to attend in July. So these little things need a solution to make that happen.

 

Also, the low speed wire stays on when the high speed one comes on. I had to use 5-pin relays to get around that with my single, 2-speed fan, basically drawing high speed power AWAY FROM my low speed relay when high speed clicks on.

So if you're using 2 fans and you want to run one most of the time and both only when needed, just use both wires to control each fan independently. Or run both off the lo speed wire and they'll turn on sooner. If you run them both of the high speed wire the fan will turn on at a higher engine temp.

 

210 is what it set at for emissions 190-200 is fine. He'll I would drill it for you if the motor is out you can always in weld the fuck out of it haha if you fuck up.


If you want it this week end just run the fans manually with a switch just don forget to turn them on. Then Setup for he ECM to contorl it When you have time. IIR I thought he truck tunes were not PWM type but not 100% sure.

 

If you want it this week end just run the fans manually with a switch just don forget to turn them on.

Bingo.

 

3/8NPT FML X M16X1.5 CONVERSION ADAPTER

There is a port in the block just above the starter. It's M16x1.5. I considered this location for my Water Temp warning light, but ended up using the heater outlet on my water pump (Tapped for 3/8).

Here is the adapter you will need, but I'm not sure if it's deep enough for your sensor.

Industrial Pipe Fittings - Pipe Fittings | MSCDirect.com

 

I went to the local hydraulic store today and found that fitting. It didn't have enough depth to engage the threads on the sensor.

I went to my normal hardware store on my way home from work. They had the 3/8" tap. But no 37/64" drill bit.

I took it as a sign.

ECM the way I wanted it. Switch for the mean time.

 

LS1 LS2 LS7 LQ4 LQ9 LS3 Automatic Radiator Fan Cylinder Head Switch | eBay

Done...

 

While looking at that I saw this. This is the plug in the head.

 

Thats the plug off the passenger side head next to the firewall.. Where i have mine screwed in.. Then my guage sensor is screwed into the driver side port.

 

I had read online where guys were having issues with the Computer turning the fan on after having it flashed... So I went this route... Right or wrong idk..

Edit: You need the Autometer 2277 adapter for your temp sensor..

 

I had read online where guys were having issues with the Computer turning the fan on after having it flashed... So I went this route... Right or wrong idk..

I don't see how flashing it would affect that unless the tuner switched it to PWM mode. (I've flashed mine countless times, fans still work.) I have seen a lot of "professional" tunes that are literally just plug-in's of the higher performance model of the same engine. IE, LS2 tunes in LQ9's and 4's, Escalade tunes in other engines, etc. If someone loaded a Corvette tune into a truck engine without switching the fans to discrete mode, I think it would result in the fans no longer working.

Also, the tables I posted screen shots of are not fully understood by many folks. It is possible to mess with those values and inadvertently disable the system.

 

I dont make the news I just report it...

Im a newbie at this building a car thing.. Dont know any better..

If you use the Computer to control your fans, can you use the factory sender to send signal to your temp gauge still?? Or does that require a sending unit??
Meaning is the factory signal from the sending unit compatible with aftermarkets gauges?

Sorry for all the questions , 3 months ago I started a similar thread in the Electrical section and I got slaugthered for being a young dumb kid and not using the computer to control the fans.. .. So I figured it out with "Google"

 

The Stock CTS for the ECM will not work with most aftermarket units. There is a three wire early ls1 cts that will work with gm temp gauges. alots of those ones on eBay.


Your talking OS flash right pat?

 

Your talking OS flash right pat?

Yes. I'm not going to say who this came from, but someone sent me their stock tune once along with their tune from a well-known, popular source. Their engine was a truck engine, I forget LQ4/9, and the tune from the tuner was just an OS overwrite of a stock Escalade tune of the same year. Since then I have seen it a few more times from other well-known tuners. I'm not a "tuner" yet. I have the software and know my way around it a good bit but I don't mess with fuel and timing tables much. I have been told by dyno shops and people who know what they're doing that the higher output engine tunes don't really leave much on the table. IE, a stock LS2 / L92 tune is about as much power as you can get without further engine mods. Thus, it makes sense to some to simply plug those tunes into similar engines and let the computer compensate for the rest, which it can do fairly well. I have no opinion as to whether this practice is ethical, proper, or smart. Just know it happens fairly commonly.

So people are running the factory unit to control fans and then they install a temp unit for their gauges???

That's what I did. I don't know if it is the most "popular" thing to do. I didn't ask anyone before doing it. Haven't had an issue out of it and therefore never a reason to bring it up and ask.

Do you think it was a mistake I did not use the computer to control the fans?

Not really. Just more wires and an additional sensor that you didn't really need and it can't be easily tuned. ('Course, if you're having your tuning done via mail order, neither is tuning the ECM.) Also, with the computer controlling them you can switch them on and off individually via the tuning software for diagnostic purposes with or without the engine running. Again, this is only beneficial if you have the software.

 

So people are running the factory unit to control fans and then they install a temp unit for their gauges???

Do you think it was a mistake I did not use the computer to control the fans?

 

Nothing wrong with not using it just easier most have a gm CTS and a aftermarket temp sender. This is typical for most swaps.

 

I have seen pictures of tapping the water pump as well..

 

Stock Sensor Mod?

Alright,
Along the same lines,
Any info on using the LS style Temp senders (Water/Oil) for aftermarket gauges using the same 680 OHM 1/4 watt resister trick we use for the tach signal?

Any worries back-feeding the ECM with more amps/volts?

Thanks
Ron

 

The ECM tuning is set to discrete in EFI Live for your tune, I just checked now that I am back home from my work trip. the temps/power the fans come on at are also at stock values for the Escalade tune you have.

The wires that you may need to control the fan relays are both on the black ecm connector. pin 17 is the high speed relay control and pin 58 is the low speed relay control. I assume you would just use the high speed control but i am not sure.

I am happy to send you wires with the right ECM pin on one end. you could probably also grab the light blue/white wire for the brake signal switch that is in the black ecm connector pin 9 and swap that over in a pinch.

I sent you a pdf with all the ECM connector pin outs for your harness in an email.

 

Thank you! I'm holding on to the ECM for a bit. I may end up sending it back to you in hopes of doing some upgrades. But that is down the road a bit as I just want to drive it for now and make sure no problems pop up.

I purchased the Painless thermostat and should have it tomorrow. I will do that until the ECM upgrades happen down the road.