Nitsuj86Iroc

Can someone tell me which one of these is for the sensor that sends to the instrument panel temp guage? Or are either of them the right one? A is what the parts store gave me then B is one that I forgot I had for my old camaro.

I have an 86 Iroc 305 TPI.

A just says "TEMP SENSOR"

B says "SENDER"

thanks for any info on these two.

FatherFrank

Looks like A is the coolant temperature sensor that is, at least in my car, near the water neck on the intake manifold.

The second I'm less sure of, but it looks like the block temperature sensor thats on the driver's side of the block, after the first exhaust port.

If I'm wrong, feel free to shoot me.

Trickster

Item "A" in that picture is like FatherFrank said, it is the Coolant Temp Sensor (CTS) and can also be used as the Manifold Air Temp (MAT) sensor. Item "B" is a Oil Pressure Sender/Switch that is used on some 5.0L & 5.7L engines. If you don't really know what yours looks like, the auto parts store will sometimes give you the wrong one.

Stekman

"B" looks like the CTS for the gauge cluster.

Trickster

You are correct Stekkie, it is the Coolant Temp Sending unit for the temp guage. I knew that number looked familiar. I just went out to the shop and found the one that AutoZone sold me for my car a couple of years ago and it was the wrong one. Mine used the slide over connector and not the spade terminal one. Another good catch for you,

400Z28Racer

iTrader: (4)

A- is CTS and it is located in the front of the engine on the manifold next to the water neck.
B- is CTS for the temp gauge and it is on the driver side in cylinder head toward the front next to exhust manifold.

400Z28Racer

iTrader: (4)

here is a pic

Nitsuj86Iroc

ok thanks guys. A for the ECU to know the engine temp, and B for the temp guage reading. thats good becasue i was waiting for them both to be wrong, but in a way, thier both right haha.

thanks again

Cadillac

Hmmm... lemon trees in the yard. Shorty headers on the block.

Where in CA?

Oh... FatherFrank seems a worthy addition to the boards with his post. Welcome!

camarohendrik

Hey Everybody!

I was just reading the forums because i have got a malfunction code no 15 on my ECM readout, my chilton book says : CTS low. So whats the faulty sensor now? Is this like in Z28 dude's picture sensor B, thus on the drivers side beneath the exhaust port?

So the car doesnt do anything with the sensor on top of the engine, that signal just goes to your gauge in the dashboard?

Hopefully somebody can help me, i have to be sure which sensor to replace because believe me... bying a sensor here in holland will caust me another arm and a leg!


C Ya, thanks in advance

Benm109

camarohendrik, I think I can help, but what's the year of your car, I just want to be sure?

Part A that Nitsuj86Iroc showed is called a CTS (Coolant Temperature Sensor). It should be located in the front coolant passage of the intake manifold, it should be next to the thermostat. The coolant temperature sensor is what the computer uses to know the coolant temperature. This is the sensor that your code 15 is referring to.

Part B is called a coolant temperature sending unit. It should be located in the driver's side cylinder head in between the front two (#1 and #3) spark plugs. The coolant temperature sending unit is what the gauges uses to show coolant temperature.

With all of that said, before you go and buy a new CTS, check the resistance of the current one. All you have to do is disconnect the electrical connection and use a voltmeter with a lead on each pin on the CTS. Here is a chart of the resistance reading compared to temperature:

camarohendrik

Thanks for the help, but thats why i got confused in the beginning...my sensor has only 1 connector on top, just like the sensor in the picture at the top of this thread. How should i measure this one? And i thought this was the one for the gauge, because the dash' gauge is broken and the previous owner placed an aftermarket gauge (also celcius instead of fahrenheit) in the car.

So the sensor thats on top of the engine in front ot intake manifold has just 1 connector, and here they place a non-original wire that goes into the dash, atleast thats what i always assumed because of the aftermarket tempgauge.

Oh yes, the year of my car is 1984, z28 5.0 ho. But anyways, how can u check the resistance with a sensor like that, do you measure at 1 connector and between the threads or something?

Benm109

To check the resistance with just one connector, just disconnect the wire, attach one lead to the connector on the temp. unit and the other lead to a good ground.

The only problem is that I don't know much about the earlier 3rd gens. I was referring to the locations of the temp. units on the later model TPI and TBI cars. The locations may be different on the earlier models.

Well, after a little more research, I found out some things. The CTS should still be in the same place I mentioned earlier (near or in the thermostat housing). My Haynes manual says that all CTS's have two-wire connectors, and according to the wiring diagrams for a 1984 5.0L carb. shows a CTS with a black and yellow wire connector. Do you see anything similar to that on yours?

FatherFrank

*Bows, waves, wipes away tear*

Glad to be aboard! Although I'm sure I'll be spreading enough accidental disinformation that you'll regret ever saying that.

FireBoid

Need help with this issue too. I have 3 "temp related" sensors, or so I'm told. 2 in the front of the intake manafold. One of which identified as the CTS. The other has an injector like connector with the metal release clip. ??? The third is the one on the driver's side head between 1 & 3 plugs. I was told that the one on the head was the one that turned the fans on. My temp gauge just stopped working. Which sender/sensor do I need to retire?

Thanks

Nitsuj86Iroc

My car only has a single fan, but iv read that a secondary fan will have its own sensor on the PASSENGER cylinder head. it just turns ot at some temp and turns it off when it cools some.

And thanks everyone for identifying these, i got lucky becasue i thought one was wrong but i guess they are both right haha.

Bill Speed

I don't know about you, but replacing my therm. was a real chore I don't wish to repeat thanks to the plenum and intake throttle body being in the way and the crap angle needed to access the water neck bolts! UGH! Did I need to consider the sensor there??
My fan/s wasn't working when the fuel pump was replaced, but hadn't been a problem before. The radiator is leaking all fluid currently. Also, if you've read this far, my original radiator is getting pulled but has much better fins for the middle section 'tank' then the one going in, said to be damaged from pulling it out. I plan to correct these by hand as best I can with micro-screw driver. Can these work fairly well if not perfect? It's a shame my broken one looks really good, almost mint!
More UGH!

BILL

Nitsuj86Iroc

Yea, the throttle body is right in the way on TPI. If you did a throttle body coolant bypass it would be easy, just take off 4 bolts and remove TB. i havnt done a TB bypass yet, and it sucked getting in there to change thermostat with the TB.

Id say if the radiator doesnt leak and the fins are straight as possible it would be like new. dont see why not

Bill Speed

I've looked at other pics and not sure how you go about that, but mine is stock. I have the right tools now, but it took a deal of effort. The fins are still mashed together in some areas...too bad to pull back out. I'll just hope it's enough good area to aid cooling. It's a shame really.. I'll hold onto mine for parts in the future
BILL