can i move my coolant temp sensor to the other side of the intake?

JuicinJake · 11-01-2009, 09:45 PM

i am running a ported cobra intake on my 306 combo. ive deleted the coolant tube and heater core. i am running the bbrc style fuel rails from kurgan motorsports. i am having trouble with finalizing a mounting solution on the coolant temperature sensor. i have a 1/2" npt port on the passenger side where the coolant tube originally mounted. i have a 3/8" npt port on the drivers side of the intake that i believe was originally plugged. i need a 90 degree adapter on either side because of the way the ends of the rails flare out. i cant find a good looking non-brass 1/2" npt male to 3/8" npt female 90 degree adapter anywhere. so i considered getting a 90 degree 3/8" npt adapter and moving it to the drivers side. does anyone see any problem with mounting it here as far as the cooling system is concerned. i know ill have to extend the wires, thats NO problem. let me know what you guys think. thanks!

AllMotorNotch · 11-01-2009, 10:01 PM

at the driver's side front of the intake the port your talking about would be used for the coolant temp gauge. i dont think there'd be a problem moving the sensor to that spot but where are you planning to use the sensor for the temp gauge?

linkmustang1235 · 11-01-2009, 11:36 PM

I'd also thought of doing this but what are u doing withe the hose from the water pump to the tube what u doing with it

JuicinJake · 11-02-2009, 12:21 AM

i am running a meziere water pump (the one without the pulley). i just run an alternator. thus those hoses are plugged at the pump. there is no coolant tube.

linkmustang1235 · 11-02-2009, 12:40 AM

cool id like to do that to what t stat housing u useing
but i have ps steering so i dont know what one to use

JuicinJake · 11-02-2009, 04:46 AM

i cant really help you on the bracket selection but i can tell you that i used aaron price's pass side mount setup for a 302. as for the t-stat housing im using a billet piece i got off of ebay thats really nice that i dont think they sell anymore. my friend bought a similar one and his wasnt as nice. anyone else got any ideas on mounting the sensor? in regards to the t-stat housing i have a screw in fitting that i believe to have AN threads with a hose end on it that goes into the water pump. i thought maybe i could find an an fitting to npt adapter (hopefully) and mount it there...

liljoe07 · 11-02-2009, 04:56 PM

Cobra intake should have another port at the back of the passenger side of the intake. My heater tube is deleted also, and I used that port. Just extended the wires.

JuicinJake · 11-02-2009, 09:14 PM

yea the thing about that is i think my plug for the rear port is "permenantly" bonded via corrosion and its also been powdercoated over. this is a super pita for such a simple thing.

95cobraguy · 11-02-2009, 10:59 PM

the coolant temp sensor needs to be in the front of the intake, NOT the back

JuicinJake · 11-03-2009, 02:26 AM

this is what i thought too. thats why i asked about the drivers side spot. the engine harness isnt back on the car yet so i forgot about the guage sensor... has anyone seen a suitable fitting to go 90 degrees from 1/2" npt to 3/8" npt. i dont want a two piece deal really, esp if its brass. that looks cheap to me and the rest of the bay is really nice. let me know...

JuicinJake · 11-04-2009, 02:01 AM

ttt

Michael Yount · 11-04-2009, 07:05 AM

Mounting the ECT on either side of the intake isn't a problem -- it will work just fine in either location. You should NOT mount it at the back of the intake however. It will register low temperatures in that location ---- you want it to measure the temps of the coolant LEAVING the engine -- and it will when mounted at the front of the intake.

LILJOE - you should relocate yours.

liljoe07 · 11-04-2009, 08:05 AM

I've checked the voltage levels coming out of the sensor. Its absolutely fine. Around 3-5* different than my autometer gauge(which is at the front of the intake). I made sure of this before I put it there permanently.

TomR · 11-04-2009, 08:51 AM

If you move the sensor you might not be measuring what you think you are measuring.

The reason they place the sensor near the water outlet is that point is the mixture of all water exiting the engine, both left and right bank.

If you move it somewhere else, like near the firewall or on the side away from the exit point, you measure only half the block and will not include any overheating from the passenger side.

When the engine is running light load and full of water that probably is not an issue. It would only be an issue if the side you were no longer measuring overheated from a localized problem to that side.

If I was watching temperature I'd probably want to see what the overall temperature for both sides was AFTER it flowed through the heads at the water exit point.....but that's just me. Other people might not care if 1-4 are boiling water (by monitoring near number 5), or even if both heads are boiling water (by monitoring at the back).

Tom

liljoe07 · 11-04-2009, 09:39 AM

Are we not talking about the ECT sensor here? And not the sending unit for the gauge?

I was under the impression that's since the Heater core hard line was removed that we were talking about the ECT sensor. For the ECM.

Michael Yount · 11-04-2009, 08:19 PM

ECT or sender for the gauge - it matters not. It should be located at the front of the intake where it senses the temperature of ALL the water exiting the block and the heads -- if you want a measurement that's indicative of what's happening temp-wise with the coolant.

rstoff · 11-04-2009, 10:34 PM

Mounting either of the temp senders in an extension off the manifold is not a good idea. They are designed to be in contact with the medium they are measuring. Putting them in an elbow or straight fitting above the collant passage will put them in an area that will trap air and give a false reading.

JuicinJake · 11-04-2009, 10:57 PM

while i know you are right in theory, im having my doubts about this actually being a problem with a small elbow. im wondering if anyone actually has trouble with this in practice. does anyone see anything seriously functionally wrong with mounting the ect in an elbow 1-1.5" in tract length away from the coolant stream? i dont think you are going to see a very big variance an inch away from the "action" but i could be wrong. someone with some experience here, please chime in...

liljoe07 · 11-04-2009, 11:13 PM

Quote:

Originally Posted by Michael Yount

ECT or sender for the gauge - it matters not. It should be located at the front of the intake where it senses the temperature of ALL the water exiting the block and the heads -- if you want a measurement that's indicative of what's happening temp-wise with the coolant.

While I agree on the Temp sender. But the ECT has a large buffer before it makes any large changes in timing or A/F once it gets above a certain temperature. For a certain Temp range almost nothing is done.

Quote:

Originally Posted by JuicinJake

while i know you are right in theory, im having my doubts about this actually being a problem with a small elbow. im wondering if anyone actually has trouble with this in practice. does anyone see anything seriously functionally wrong with mounting the ect in an elbow 1-1.5" in tract length away from the coolant stream? i dont think you are going to see a very big variance an inch away from the "action" but i could be wrong. someone with some experience here, please chime in...

Never tried it personnaly, but I was trying to help one guy on another forum. He had his ECT mounted in a T-fitting above the intake, in a coolant line going to the heater core from the manifold port. No matter how long he let his engine run, the ECT would throw a code for being out of range. This would send the ECM back into open loop. In stock form, if the ECT sensor doesnt see temps of 160° or above for a drive cycle, then it will go in to open loop. His only fix was to mount the ECT directly in a coolant passage

Ray III · 11-04-2009, 11:38 PM

You can pipe any way you want for an oil pressure sender, but coolant temperature senders need to be in the stream.

Michael Yount · 11-04-2009, 11:59 PM

x2 - in fact, if the elbow is 'above' the coolant stream, air is usually trapped in the fitting and the sensor isn't in contact at all with the medium it's supposed to be measuring.

liljoe - don't confuse the fact that the ECT/ACT may tolerate large temp ranges without impacting outputs of the ecu too much with whether you're measuring what you should be measuring. Any sensor that's supposed to be providing the ecu with a coolant temp needs to be in the front of the manifold. There's simply no way around it.

JuicinJake · 11-05-2009, 03:27 AM

well this is all VERY interesting and VERY helpful. i really appreciate every single person that has contributed to this thread so far. it seems the real question now is: WHAT should i do with the sensor? it seems that the drivers side port is the best bet, as the passenger side requires a pipe thread reducer, which increases the installed height. herein lies the problem. thats what i dont have. im going to go out to the shop in the next day or two and try to get the sensor screwed in under the rail on the drivers side. then i can see if its possible to install the engine harness with the fuel rails on. ideally id mount it right on that thermostat housing but i just dont think there is enough room to have a reducer in there. i think the hex head alone would interfere with the main part that the radiator hose connects to. nonetheless ill try to find an adapter at the speed shop. it looks to me like an 8an o-ring fitting. and id need that to transition to a 3/8" pipe and that makes for a very thin, and likely nonexistant fitting. what is everyone else doing? running stock rails?

liljoe07 · 11-05-2009, 08:22 AM

As I've stated. I've measured the voltage coming out of the sensor. At operating temp.

I know it works in the rear passage.

The temp range is 60-70* before any significant changes are made. If you have that much of a difference between banks, you have other problems. The temp range before the ECT throws a code, is below 50* or above 250*. About 220ish it starts to retard timing and mess with the fuel enrichment.

There is more than one way to skin a cat Mike.

Fact is the ECT is not that finicky of a sensor. But it is important.

Michael Yount · 11-05-2009, 08:45 AM

What it does Joe is measure A temperature in the rear passage; not THE temperature the ecu is expecting to see. Sometimes they may be close to the same - but not all the time. The coolant hasn't picked up all the heat it will until it's leaving the engine through the front of the intake going into the t'stat. As stated before - the fact that it's 'working' the way you have it doesn't mean you have it in the proper location. Where you have it located has you exposed to the ecu getting data that's not reflective of the actual operating conditions of the coolant. You may be comfortable with it located there - but it's important for everyone else following along to understand the limitations of your choice of position for the gauge and/or senders. As mentioned before -- there's no way around it. Your choice of location is suboptimum at best; problematic at worst. The simple fact is it's not 'working' unless it's sending the data the ecu expects across the full range of operating conditions it could see. And it can't 'see' the full range of possible conditions (especially problem conditions) where you have it located because the engine hasn't put all the heat into the coolant that it can/will at the back of the block/heads/intake. The coolant flows from front to back in the block and then enters the heads at the back and flows to the front before heading to the rad to reject the heat. You must measure where it's LEAVING the engine if you want an accurate reflection of temperature for your sensors/gauges. There may well be more than one way to skin a cat, but there's only one way to deal with the physics of coolant flow and heat transfer in these motors.

" If you have that much of a difference between banks, you have other problems. " No question about it -- and with the sensors at the back of the intake, the data coming from the sensors isn't likely to highlight the problem for you - which is PRECISELY what the sensors are there for. To point out potential problems. They can't do that if they're not located properly.

liljoe07 · 11-05-2009, 02:22 PM

I get where you're coming from about it not being in the correct spot.

But if the ECU is expecting to see a certain temp, then what is that temp? That Temp range is wide. The ECT just looks for a given range in temps.

With the ECT sensor having a large range that it does before making adjustments, an expectant temp is not going to had.

It does nothing until temp are in the 220 range, higher for the ACT. The Water Temp gauge will be the life line. Its still going to read temps in both banks(considering a aftermarket gauge is used). And if you pay attention to that gauge, you will know something is wrong way before the ECM does. Specially with a 200* range before the Check Engine Light comes on from an ECT sensor out of range code.

But I admit, its not considered proper, but it works.

I've had it this way for about 2yrs. Car gets 23mpg on average on the highway, with 4.10's mind you. Performance has not suffered considering the MPG's and rear gearing I have. Hell, most don't get that with a numericaly lower rear gear.

Michael Yount · 11-05-2009, 05:42 PM

We're zeroing in on alignment Joe -- it hasn't been an issue because everything is working as it should. Placement in the rear of the intake becomes an issue when things DON'T work as they should -- you simply haven't had that occur yet. Great job on the mileage. I took mine on a trip to Augusta, GA a few weeks back -- got 27.5 mpg on the trip down. 3.73's and a slightly shorter tire than on the Stangs (makes it like a 3.90 on a Stang). Fuel to the top of the neck on both fills and an accurate speedo. Not bad for a brick.

liljoe07 · 11-05-2009, 06:45 PM

This is how I see it Mike, even with the sensor in the factory location, if there was a problem on the left bank with let's say a 40* higher temp or 40* lower temp, the ECT readings is still not going "highlight it" as a problem. There is just to much tolerance in the ECM to make a change.

Its been fun Mike, as always.

I have family in Augusta haven't been there in a while though.

27mpg's is damn good. I too run a small tire 245/45's, at 65 MPH, it turns around 26-2700 RPM's, only weight reduction I have is a rear seat delete and Smog and A/C removed.

lonnie1952 · 11-06-2009, 02:02 AM

Quote:

Originally Posted by JuicinJake

i am running a ported cobra intake on my 306 combo. ive deleted the coolant tube and heater core. i am running the bbrc style fuel rails from kurgan motorsports. i am having trouble with finalizing a mounting solution on the coolant temperature sensor. i have a 1/2" npt port on the passenger side where the coolant tube originally mounted. i have a 3/8" npt port on the drivers side of the intake that i believe was originally plugged. i need a 90 degree adapter on either side because of the way the ends of the rails flare out. i cant find a good looking non-brass 1/2" npt male to 3/8" npt female 90 degree adapter anywhere. so i considered getting a 90 degree 3/8" npt adapter and moving it to the drivers side. does anyone see any problem with mounting it here as far as the cooling system is concerned. i know ill have to extend the wires, thats NO problem. let me know what you guys think. thanks!

It should Work.
We have built a few EFi systems...Put it anywhere on the intake you should be fine.
Even mounted in the cylinder head worked fine on some engines
The cylinder head temp will actually be the hottest spot under load if their is room for it

While keeping it near the outlet the way the factory did is maybe the best you will see NO issues Moving it
You should see no more than about 2-4 deg variance in temps from front to back of the intake

You will find that with a custom EFI install... the sky is the limit for mounting sensors (too a Point)

1952

gupthefish · 11-07-2009, 12:35 AM

I am running a t fitting on my stanag because mine is a daily driver, and when i switched intakes, the threads twisted off the old coolant pipe, so thjis thread is interesting to me, because i feel mine is not getting the most accurate reading because the sensor is mounted on the top of the "T" so my suggestion/question is...... can we get a 1/2" thread sensor???? then i could just t off a coolant hose and run that to the heater core. just a thought, or am i missing something??

95cobraguy · 11-07-2009, 02:17 AM

i deleted my heater lines as well and run a 1/2 to 3/8 npt reducer for the coolant temp sensor and have had no problems.

gupthefish · 11-07-2009, 03:11 AM

Quote:

Originally Posted by 95cobraguy

i deleted my heater lines as well and run a 1/2 to 3/8 npt reducer for the coolant temp sensor and have had no problems.

my bad, when i said mine was a daily driver, i ment mine still had the heater hoses. sorry to confuse. yes, im running a T , so one side comes from the intake, one goes to the heater core, one goes to the ECT .

TomR · 11-07-2009, 08:38 AM

A lot of wrong stuff can make people happy. People will swear by some silly things that make no sense.

If you move the sensor to the driver's side front you measure temperature of coolant only from the driver's side of the block, but at least it is after coolant passes through the one head where it picks up a lot of the heat.

If you move it anywhere on the back, it only measures block temperature without direct heating from the heads. The block and head stay somewhat close to the same temperature at low speed low power operation because they are bolted together and only insulated by the head gasket, but not close at all at a higher load.

If you put it near the water exit where it has flowing water from both sides of the manifold, you measure the mean temperature of it all.

If I had a gauge that said "water temp" or an EEC that used it, I would at least want it to be the water temp. This is why tachometers are not driven from the drive shaft, and speedometers are not driven by the crankshaft. We want them to read what we want to measure under all operating conditions, not just some of the time.

If you have trouble getting special pipes and fittings, get away from parts stores and hardware stores. Go to McMaster-Carr Supply.

Tom

liljoe07 · 11-07-2009, 10:03 AM

Your Tachometer and Speedometer example is just terrible. Your talking about 2 things that measure an exact. Then trying to compare it to a sensor( ECT, Not the one for the gauge) that measures a wide range. Range that has no effect on what the ECM makes corrections for.

We will use this chart.
http://www.veryuseful.com/mustang/te...sModifiers.gif

Now tell me this, If I have a bank running 120° and one running 210°( extreme case I know, and will probably never happen, but it helps get the point across), what does the ECM do?

Going by that chart, your reasoning is backwards. There is more of a change at low loads then at high loads for a given Temperature and Load range when concerning the ECT sensor and Air/Fuel.

Timing.....Nothing is done in the range between banks that I listed above.

So how important is it for the ECT to be the Factory location?

You have a 80° or more range where the ECT does nothing to timing, a 30° or more range where it does nothing to Air/fuel at low loads, and a 60° or more range at high load where nothing is done on the Air/ Fuel side either.

And when it does do something, its fairly mild.

TomR · 11-07-2009, 11:02 AM

Quote:

Originally Posted by liljoe07

Your Tachometer and Speedometer example is just terrible. Your talking about 2 things that measure an exact. Then trying to compare it to a sensor( ECT, Not the one for the gauge) that measures a wide range. Range that has no effect on what the ECM makes corrections for.

That makes no sense. My example was simply to show when we measure something, it is generally best to measure in a way closest to what we are really trying to measure with the least amount of error.

Quote:

We will use this chart.
http://www.veryuseful.com/mustang/te...sModifiers.gif

Now tell me this, If I have a bank running 120° and one running 210°( extreme case I know, and will probably never happen, but it helps get the point across), what does the ECM do?

You are confused. The charge temperature is an extremely variable number because the time air spends getting warm varies with airflow, the time spent inside the manifold and other areas that heat outside air varies with how fast the air is moving through the system. You are comparing the charge temperature to something with high thermal lag or latency; the entire block, heads, manifold, and cooling system.

The water temperature delta is entirely different. The water is heated by the cylinder walls, but also significantly heated by the combustion chamber and exhaust port area of the heads. The heads are thermally connected to the block, the thermal resistance would be that of the metals in the path with some insulation caused by the head gasket. If things are running at low temperatures compared to coolant flow, the rear of the block or any area inside the system would have close to the same temperature.

If you suddenly run wide open throttle the temperature delta between the outlet of the heads and inlet to the block gets a whole lot greater.

Now if you don't care what the water temperature leaving the heads is, which is the hottest point, and you really only care about the water in the block which is someplace between the radiator cold water exit (lowest temperature point in the entire system) and the highest temperature point, then measure at that point.

Myself, I want to know the maximum temperature of the water in the system at any instant of time. I don't want to know some meaningless temperature that can be anywhere between the temperature of the radiator exit and the head exit points.

So if that rows your boat for you, measure the wrong place and be happy.

Quote:

Going by that chart, your reasoning is backwards. There is more of a change at low loads then at high loads for a given Temperature and Load range when concerning the ECT sensor and Air/Fuel.

That has nothing to do with the coolant system.

Quote:

You have a 80° or more range where the ECT does nothing to timing, a 30° or more range where it does nothing to Air/fuel at low loads, and a 60° or more range at high load where nothing is done on the Air/ Fuel side either. And when it does do something, its fairly mild.

If we don't care if the water is really near boiling or not, or the computer doesn't care if if the ECT is 20-50 degrees off, then obviously it doesn't matter where we measure things. Measure the radiator outlet or the block water someplace.

In my case I really want to know what the highest temperature of water in the cooling system is and the EEC wants to know what the intake manifold is seeing, so I will measure the spot where the system is most likely to show the correct reading.

As a general rule it is always best to not compound errors by doing something foolish, although we can argue how foolish "foolish" really is endlessly.

Tom

liljoe07 · 11-07-2009, 12:05 PM

Dont side track the Topic, This is about the ECT sensor and its reading to the ECM. ONLY. And you totally side stepped every question I asked of you. Your trying talk about heat transfer through the block and heads, and every one else is talking about the ECT SENSOR and what effect the ECM makes from its readings.

Technically, having the ECT in the back of the manifold on the Passenger side, would be measuring the Temp coming out of the Head, Thats the point where it crosses over to the other side. While the Temp gauge measures everything.

Remember ECT sensor ONLY. WIDE RANGE where nothing is done to TIMING or A/F. So explain why you need a wide tolerance sensor in an EXACT SPOT?

Quote:

In my case I really want to know what the highest temperature of water in the cooling system is and the EEC wants to know what the intake manifold is seeing, so I will measure the spot where the system is most likely to show the correct reading.

Thats what you have a gauge for!!!!!. The ECT is not going to do this. Period. Failure code range is 250 damn degrees.

You can argue all you want, there is too large of a range to say the ECT needs/has to be where ford put it. How about accessability for the sensor is why its there.