Temp Gauge Sender?

michbc3

michbc3

Well-Known Member
#1
#1
Can anyone tell me where I might be able to buy a temperature sender for the temp gauge? The sender on my car is brass with a single stud connector on the end. A green wire coming from the wiring harness with a slide connector attached mates with it. This sensor threads into the front of the intake manifold (I believe it is the center hole in front?).

I did a quick search at Advance Auto Parts and their photos show a sensor with a 2 pin weatherpack type connector - and that's not what I have.

I would appreciate knowing the part number and a source where I can find what I need.

Thanks, Bob
 
Nick Wise

Nick Wise

Well-Known Member
#2
#2
I wouldn't buy form advance or autozone( I don't trust anything electronical from them). Should be able to get it from NAPA. I just ordered an ECT from NAPA. not sure which one I am getting though, whether it is the gauge sensor or the one for the computer(2 wire) I will let you know the part # if it is the single for the gauge. Forgot they have 2 when I ordered and they didn't ask which one it is.
 
WS6

WS6

Stay thirsty my friends
#3
#3
You probably already know, but it's GM #25037346 and Delco #213-80.

It shows it on the right side of the intake w/button terminal.

And it is still available for around $40 from GM


..
 
michbc3

michbc3

Well-Known Member
#4
#4
WS6 said:
You probably already know, but it's GM #25037346 and Delco #213-80.

It shows it on the right side of the intake w/button terminal.

And it is still available for around $40 from GM


..
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Nope. Didn't know. Great information. Apparently this is one of the few parts that GM still carries for this car. Yes, a button terminal is a good way to describe it.

I'm on travel right now (Tampa, FL) and researching this is difficult. Maybe I can call my Pontiac dealer in VA and have it when I return.

I had the weirdest thing happen to me yesterday. My new engine has 300 miles on it and my tuning has been progressing well. A loud black Mustang convertible squared off with me, so I decided to give my engine it's first "test" run. Annihilated that Ford without difficulty, then the car would not idle - almost stalled. Had to double foot it to keep it from stalling. Being only a mile from home, I got it home OK, then noticed that engine temp was 220 on the gauge and 224 as read by the laptop, high speed fan was already running like crazy. Usually that only turns on about 30 seconds after engine shut down for a few minutes. Opened the hood and it didn't seem like the engine was unusually hot. I could still hold the upper radiator hose with my bare hand with no discomfort. The hose had pressure - but was not hot like it would be if the coolant was really at 220. Could also feel the fins on the radiator - not very hot. So since this sensor both drives the temp gauge and feeds the ECU, it's probably the culprit.

If the sensor tells the engine that it's at 220, the idle fueling would be very different than when it is at 175 (like it is normally). I just disconnected the battery to stop the "fast" fan from draining it after a couple minutes.

Thanks for the help. I'll give GM a call tomorrow. Bob
 
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WS6

WS6

Stay thirsty my friends
#5
#5
michbc3 said:
So since this sensor both drives the temp gauge and feeds the ECU, it's probably the culprit.

If the sensor tells the engine that it's at 220, the idle fueling would be very different than when it is at 175 (like it is normally). I just disconnected the battery to stop the "fast" fan from draining it after a couple minutes.
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I think you may be mistaken a bit here or I am, there are 3 different coolant "switches" One for the gauge only, one for fans and one for the ECM reference.
See picture attached...just be sure you get the right switch, and I believe they are all still available..

..
 
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michbc3

michbc3

Well-Known Member
#6
#6
Thanks for the pics. You've got me thinking. If the ECM sensor is separate than the gauge sender, then my detective work is wrong somehow. This will require more investigation. I will tell you though that the radiator hose just didn't feel like 220 degrees hot. And the engine compartment didn't seem very hot either when I opened the hood. Well, my "sense" of heat using my hand is uncalibrated of course. When I get home, I'll have to do some more testing. In the meantime, I'll hold off on buying any sensors. Thanks!!

Bob
 
michbc3

michbc3

Well-Known Member
#7
#7
I'm surprised that some have not yet suggested a blown head gasket yet. I guess that's because nobody wants to hurt my feelings I'll bet!!

Anyway, I just got home from Tampa, FL an hour ago. I will set aside some time this weekend to do a leakdown test. Hopefully this is not a big deal, but it will get fixed, regardless..

Best, Bob
 
michbc3

michbc3

Well-Known Member
#9
#9
I didn't experience any danger signs. The A/F is set at 12.4 from 0 up to 11 lbs of boost, then 12.1 A/F from 11 psi to 15 psi (wastegate set at 15). No strange noises (rods or valvetrain) coming from the engine. This power burst was less than 1/8th mile. No knock noticed. I have to also wonder if the primary fan was operating. I forgot to check that with key on, engine off on Sunday when I noticed that it was hot.

Well, I'll start with a leakdown before driving it anywhere. That has to be done anyway. I turned the key tonight. Ran fine cold. Didn't want to run it long until I know more. Thanks for following along.

Best, Bob
 
WS6

WS6

Stay thirsty my friends
#12
#12
I dunno, that's over ragged edge of detonation, in my mind anyway. I target 10.5 and most of my KR happens above 10.8 and I spray alky.


...
 
michbc3

michbc3

Well-Known Member
#13
#13
WS6 said:
I dunno, that's over ragged edge of detonation, in my mind anyway. I target 10.5 and most of my KR happens above 10.8 and I spray alky.


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Regardless WS6, I appreciate hearing different opinions. At power, my exhaust is so rich already that it blows black smoke. Tuning books that I've read have recommended as rich as 11.7 A/F at full power for highly boosted engines. 15 psi was the factory boost setting, so I don't really consider that high boost.

Though I was not watching my knock gauge, I heard no knock and didn't experience any stumble - just smooth power. I have yet to see any white smoke come out of the exhaust - which would indicate a blown head gasket to me. I'll let everybody know what I find out on Saturday - after the leakdown test.

This is not the original block and heads - which are intact and stored in the garage. So if this turns out to be a "learning" experience, so be it. No worries.
 
WS6

WS6

Stay thirsty my friends
#14
#14
So, this is a new motor?

Are you logging any runs that can show A/F's/boost/ MAF and KR throughout the run?


Matters not though...you've got a handle on this now
 
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michbc3

michbc3

Well-Known Member
#16
#16
WS6 said:
So, this is a new motor?

Are you logging any runs that can show A/F's/boost/ MAF and KR throughout the run?


Matters not though...you've got a handle on this now
Click to expand...
New engine. 350 miles. 8.5 to 1.0. No. Not doing any runs or logging at all. This was about a 6 second "push" on the gas on the street. No MAF. GEN7+ is a speed density system. If stock boost is 16.5, then all the better that I was at 15 psi. I'll get back to you all.

Best, Bob
 
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michbc3

michbc3

Well-Known Member
#17
#17
Probably False Alarm

Ok. Last night I checked operation of the low speed cooling fan by grounding out the sensor - worked fine. The high speed cooling fan has been working as you know.

Did leakdown and compression tests. No problems found. While doing the leakdowns, I also looked for bubbles in the radiator - saw none. The radiator initially looked like it was one or two inches down yesterday. But it only needed one to two cups of antifreeze to top it off. Also, when I looked at the oil yesterday, it looked a little emulsified to me (probably jumping to conclusions). But today in the sunlight, it looked normal. Results of tests below:

Cylinder Leakdown % Compression

1 24 165
6 20 165
5 16 170
4 21 165
3 19 165
2 19 165

I recall that the ring gap on #1 was wide when I put this together, so 24 is not a bad number on that cylinder. The engine started and ran fine when cold. I plan to take it out this afternoon to see if it stalls when warmed up. I don't expect any trouble. Looks like this was a false alarm. Whew.

I'm going to keep a closer eye on temperatures. Though the fan itself works, it's indeed still possible that the low speed fan sensor could be bad. Better install another one just to make sure.

BC3
 
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