"under"heating??

[jaymac]

During my GT40P swap, I flushed and filled my coolant (flushed ALOT), and put in a 180* stat. Ever since, The gauge only reads to the first white line all day long, which by my guesstimations is less than 160* If I let it idle for awhile, it might reach the second white line.
After a pass at the track, it will reach the halfway point (200 by the stock gauge), so it does respond to actual increase.
Before the swap, it would usually ride around at the halfway point, then if I was sitting in traffic, it would climb 1 or 2 notches above that, which is not surprising, considering how VISCIOUSLY dirty the system was when I flushed it!!!!!

ANSWER TO 1ST QUESTION:
yes, it is a stock gauge.
Yes, I want to get an aftermarket one. I'm thinking electrical, unless someone can steer me in the other direction.
I jusr want to know if it's normal (or possible) for the engine to operate where the gauge currently "says" it is.
Thanks!
J

 

[Paul Perreca]

factory gauge is prob off...

 

[mackey]

The temp reader sucks. I have both in on my car and the stock one is way off.

 

[HISSIN50]

Agreed. I like the gauge error idea.

FWIW, I prefer mech temp gauges because of the full sweep. An elec gauge's needle can be worth 20* in its width.

What one can do: On a cold motor, one can pop the rad cap and stick a turkey thermometer in the rad orifice and start the motor (Be very careful of splashing hot coolant, moving accessories, etc). Watch the thermo as the car warms up and see how it corresponds to the stock guage.

Good luck.

 

[jaymac]

I will most likely go try the turkey thing, as well as a new gauge anyway.
W/ the different gauges, do I need to buy/install new sending units, and /or drill & tap new holes as well, i.e., remove and install the upper intake???

 

[jaymac]

Ok, update:
I started the car w/ the meat thermometer, and let it warm up. After about 10 min., the stock gauge read about 150, and so did the meat thermometer.
I capped it and drove home (5 min.). The gauge still read 150, but I left the car runing and using a towel, took off the radiator cap, stuck the thermometer back in, and it went up to about 177*, while the gauge still read 150sih.
Gauge problem?
Seems like at this point...
I swapped my stock temp sensor over to the new mainfold when I put it in- any chance I did something to it when I swapped it, or are they pretty durable, straightforward pieces?

 

[Kerpal]

My gauge has been indicating lower temps than normal for no apparent reason lately... and it's the hottest right now it's been all year. After installing my Griffin radiator and 180* stat the gauge usually never moved from 1/3 up, but this past week it's been at more like 1/4.

I'm thinking it's gotta be the sensor...

 

[HISSIN50]

The senders are pretty straightforward. About the only thing one can do to one is ground it (can help if a ton of thread dope was used on the threads). The stock gauge is just a POS (my stocker always read ~20-45*F cooler than the temps read from a mech gauge mounted in the stock location).

I still definately like your getting an aftermarket gauge idea (even if just a cheaper one from the parts store).

FWIW, with a 180*F balanced stat, when it is open my stock gauge sender location (front of the lower intake) can read 175*F or so. Just different temps in different spots IMHO (the stat works and all that).

Good luck bud (and dont use that turkey thermo for living consumption again. ).

 

[jaymac]

how do I ground it- just run a ground strap from the sending unit's post to any existing ground?
I did use teflon tape on the sender...

 

[HISSIN50]

how do I ground it- just run a ground strap from the sending unit's post to any existing ground?
I did use teflon tape on the sender...

No! If you put a ground on the sending unit's post (where the sending wire attaches), you will just peg the gauge on high.
You want to affix a ground wire to the body of the sender, somewhere away from the sender wire and connection. You can even zip tie or duct tape the wire to the sender's body to do a quick check (or hold the wire to the sender body if you have an assistant).
You could ohm out the sender instead, but most folks prefer to just ground the sender.

Good luck.

 

[jaymac]

OK, so I installed the gauge today.It was VERY hot and muggy
Got it done, and temp reads right to 180. In the uture, I'd like a nice full sweep, cuz -just like you said- the difference between 180 and 200 is very small. But at least for now, I have a more acurate idea of what's going on!
Little PITA, though!!
Thanks for your help!

 

[HISSIN50]

Glad to hear you got it installed. Even the electric is much better than the stocker, as you can see.

 

[jaymac]

do you have a mech. full sweep?
Pics?

 

[HISSIN50]

I have a mech (full sweep) temp gauge in both stangs. I am not one to post pics (or have an avatar or sig). LOL (I am a caveman).

 

[jaymac]

wow...11,492 posts and NO pics....that's actually quite impressive...

 

[HISSIN50]

wow...11,492 posts and NO pics....that's actually quite impressive...

I dont know how to do that stuff so I just post. I probably do have a record or something though, even if just because of my lack of computer savvy.
Andy, Patrick and some of the guys have sent me avatars that I could use. Chris and a few others have offered to host pics for me. I just never really cared that much. Y'all have much nicer stuff than I do anyhow.

 

[jaymac]

Y'all have much nicer stuff than I do anyhow.

Hmm...for some reason I don't believe you...
Even if you had CRAP, you have TWO pieces of crap, so if one breaks or is undergoing a project, you still have another stang - you win!
But either way, i don't necessarily believe you...