Here is what the scanner read

Here the temp gun reading pointed at wp

Driver head



The gauge read close to where the head were

 

I was experiencing identical if not similar issues with my wife and I's beater Civic a couple years ago and traced it down to a coolant leak, enough of a leak to drop the level down too low after a week or two. Have you confirmed that the coolant level in the reservoir stays consistent from day to day?

Sounds liked you've bled the hell out of the thing but have you been bleeding it exactly per the directions on the Shbox site?

Good luck, it's the dumb **** like this that can be annoying AF sometimes.

 

Easiest way, and biggest PITA for you to figure out if there's air in the system is to drain the block and radiator and measure what was in there. I do believe the system has a 16qt. capacity. Go to shbox's site to verify.

 

man tell me about it. I took it to a real good radiator shop out here in the sf bay area and they bled it real good. I have no coolant leaks. i think it's a electrical issue thought . My scanner would say 200 but temp gun will say 162 or 165. If which is confusing cause the temp in the motor and what the pcm sees is completely different.

 

I don't think there's air in system anymore after that last flush. I think this is electrical problem Cause why would the pcm read a different temp then what the motor really is? Its like the pcm thinks the motor is hot but really not. The pictures above shows and yesterday while warming it up i was getting -40 sec temp drop on the scanner. I tested the ECT sensor wiring harness while back and it came up 4.9v, that's the normal range. Do anybody know the real part number to temp sensor on the wp? Maybe i got the wrong one again.

 

Sorry if I missed this but did you try a new temp sensor? According to the ACDelco parts lookup, RockAuto and Summit, there's several GM/ACDelco sensors that should work and it appears the GM one you have is correct. Have you fixed the wiring?

As crazy as it may sound, I'd bleed it again and I'd follow the shbox directions to a t.

 

I tried to replace the w/p sensor some years ago for no apparent reason. Just to put a new one in when I did a cam swap. Ordered one from Autozone, put it in, started the engine and immediately got an SES light and the fans kicked on. Have never tried to replace it since.

Water pump sensor GM part number:
15326386


https://www.summitracing.com/parts/ado-213-928

https://www.gmpartsdirect.com/oem-pa...ensor-15326386

 

Hmm maybe I got another defect, it's a ac Delco but it's from Amazon. I check the wire volts earlier that goes to the temp sensor on wp and this what i got

I even test the black lead that pcm uses with the ohms setting like stated on shoebox site and i got a 4.53. I don't know if that a good or bad range.



When i plugged in the scanner i got some unexpected codes. I did pulled the ECT sensor plug to test it, i don't know if that would trip these codes.

​​​​​15326386 is the wrong one, that's for a 2011 Cadillac. AZ gave that one when i gave them that part number. The correct one 213 4396

 

ALSO i pulled the maf sensor and the iat sensor and no ses light came on or fans. But when i pulled the ECT sensor plugged then light came on and fans. I'm confuse that on that part, is it cause i have tune? I smell bad pcm for some reason. Or the alternator could be causing all these issues, it does make a squeaky sound and clacking sound and i be having voltage drops.

 

What I supplied is a GM part number for specifically for the w/p sensor. Must be out of date now.

 

I'm even skeptical about the the correct part number, cause when i search it up its discontinued. I wouldn't be surprised even Amazon sent me the wrong sensor. Why do all of gm temp sensor looks identical?

 

The original PN for the sensor in the WP(93-95) is 12146312...that was superseded by 15326386. Rockauto lists Delphi TS10075 as an equivalent replacement for 12146312 and 15326386. 15326386 is not discontinued.

 

Thanks. I'm gonna buy the part # I'm gonna also purchase a new alternator cause my car be having voltage drops.

 

Go here....
https://www.mediafire.com/?40mfgeoe4ctti

Download the '95 service manual....do some reading. Page 2401 is DTC 42 with some diagnostic charts. Scroll on down for DTC 51. That is a PCM checksum error.....if you clear it, does it come back? That's a little concerning as it means various memory/program segments are not in their expected values.....possible corrupted program or memory. If you don't see the code return after clearing it....I'm not sure I'd worry about it....but it might point to a wiring or voltage issue. You mentioned voltage drops....how do you know you are having voltage issues?

Off the wall question.....do your headlights pulsate high and low(bright/dim) at night?

If code 51 comes back after clearing it.....I'd reflash the PCM with a known good program(good checksum value) to see if it corrects the error. However.....there is the possibility that a reflash may fail if the memory is having trouble. I'd have a known good backup PCM on hand before trying it if you depend on this car as a daily driver.

The other thing to make sure of is that there are no wiring/voltage supply/ground issues.....especially if you replace the PCM. You don't want it zapped should the present one turn out to be bad.

I saw where you called on Shoebox and Injuneer(or maybe it was another guy that did this....). Shoebox does come by here, but Injuneer is on another forum.
https://www.camaroz28.com/forums/lt1...engine-tech-9/

 

FYI, the cooling fan relays are on the air pump relay circuit on a '96(and I assume '97). Edit....I don't see the same thing on a '95.....so the air pump is not on the fan circuit for '95(and maybe earlier years).

I warped my heads due to that fuse blowing. I let the engine idle while pulling the air pump code it set when the fuse blew....I didn't know the cooling fan relays were on that circuit until I smelled coolant, looked up and the temp was pegged at 260.

 

Today was the first time I've seen that 51 code. It cleared and hasn't came on since. Yes, when the voltage drop my light dim out then come back to normal. I notice on the scanner that my battery voltage drop to 12.8 to a 12.4 most of the time its around 13.0 to 13.5. I would have to check all the grounds to see if there fine.

 

Sheesh that's terrible. The smalls thing can turn to the biggest problem with these motors. Your car didn't throw a ses light when your fuse blew? the fans will kick on to prevent overheating. When Mines blew it threw a code and ses light and fans came on.

 

Alrite guys so i got a couple things in mind that I'm gonna do. I just order a new ac Delco alternator cause i realized the one i have is reman one with that I'm changing belt and tenisioner. See if that fixes the voltage drops.

I also got temp sensor p/n 12146312 on the way, all parts should be here by Tuesday. If this doesn't workout im thinking pcm is corrupt. Cause I've done a lot of testing to kinda rule out things.

 

I notice while expecting the front that the upper part to the low air dam that feeds air into the radiator is not bolted up. Will this cause lack of flow while cruising?

 

How's it going guys, and happy new years. I know this thread hasn't been so active in the past weeks but I'm still trying to figure this problem out. Recently I just replace

1. Acdelco alternator (Cause the one i had was reme)
2. Belt Tensioner
3. Accessories Belt
4. ECT sensor (The right one)
5. Battery

And I'm still getting voltage drops (Mainly when put in gear) , my scanner see 13.4 but occasionally it drop to 12.4 I checked the wires to both alter and battery and they look good. I use my dmv while the motor was running and got a 14.53 which is a good range in idle, but when put in gear car acts like it wants to die and at that moment my scanner says 11.7 There are some grounds that's look dirty, I should clean those.

And also I still have the weird temp rising issue, the new temp sensor and bolting up the upper air dam flap thing kinda help cause when I'm on the freeway the temp will stay steady and drop at sometimes. But once I get off the freeway and drive in some stop and go in the city it's immediately start rising. Like it can be at 188 and next thing you know it's at 200. Even the fans comes on at different temperatures, and like stated above I have a tune where my fans should come on at the temp it's set at. But when i check the ir temp gun, it reads 162-169 at the waterpump. Cooler then what the temp says on the scanner and gauge. I think the pcm is bad because of that code 51. Hasn't came on since, but doesn't mean its not bad. That could be a hint that it is and all these weird behaviors that I'm experiencing is actually the pcm. All these symptoms but no check engine light, not even stored codes are present. I sent my old pcm to my tuner to flash the same tune that I got on the service one in my car and will see what happens. I'll update you guys soon after.