TEMP GAUGE WAY UP!! car running great though.

[savegoodautonfg]

Ok if you read my threads alot you already know that i got the rebuilt motor and everything. well tonight im driving home on the parkway by me and i get into town and i see my factory temp gauge all the way up. Now, i get home and turn the car off and the needle goes up so high you can barely see it. 20 mins later i go back outside turn the car on and the temp gauge is sitting half way. I don't understand what is going on?

Could it be the temp sender and if so where exactly is taht located? Maybe a picture of something please.

Thanks again

 

[vristang]

The gauge sending unit is easy to find. It has one wire coming out of it, and it is threaded directly into the lower intake toward the front passenger side.
Make sure you have a good connection, and there is no corrosion in the connector.

How long since the new motor went in?
It is very common to have some air pockets in the cooling system after replacing the coolant.
You may just need to burp the system a little better.

What T-stat are you using? 180? 195?

Can you provide more details on your cooling system?

jason

 

[savegoodautonfg]

I'm using 180 and the engine just went in a week ago. since i got it back its been running beautifully.

ALso you stated taht

The gauge sending unit is easy to find. It has one wire coming out of it, and it is threaded directly into the lower intake toward the front passenger side.

Can i get to it from the top of the engine with no problem?

 

[savegoodautonfg]

Can you provide more details on your cooling system?

TO answer taht

I have stock radiator, new water pump, fairly new thermostat...

 

[HISSIN50]

The gauge sender is on the driver side from my normal perspective. It's close behind the dizzy.

You definately can remove it and swap it in about 2 mins easy. It's very accessible.

Jason's got some great ideas about burping, etc.

Good luck.

 

[savegoodautonfg]

If it is connected completely right, could the sender just be faulty?

 

[Roland69]

airlock's make some crazy temp problems happen. it's like the little green coolant devil lol

 

[vristang]

As JT mentioned it is pretty easy to get to the sending unit. It would be a quick change, and probably less than $20.
It should be posssible to test the sending unit with heated water, a thermostat, and an ohm meter, but I don't know the specifics as to what resistance you should see at a given temp.

The sensor could be bad.
Since the motor was just built though, I would lean toward the sensor being fine, and the problem being air pockets.
Air in the system can be very frustrating. It will show up at odd times, and sometimes seem to disappear.

Try this...
Jack the front drivers side of the car up a little. You are trying to elevate the cap of the radiator so that it is the highest point in the cooling system. Then go through the normal process of burping the cooling system.
With the cap off, start the car and let the motor warm up. Remember to never pull the Rad Cap when the motor is hot! I had a Football Coach in High School who did this, and the entire front of his chest and arms were scared from the coolant burns.
Let the motor run for a while and run the heater on max to help purge air from the heater core.

Others may have more ideas?

jason

 

[HISSIN50]

If you get a parts store sender, I paid $4.19 at CSK for one.

Jason's burping thoughts sound good to me. If you have an old retired turkey thermometer, you can use it to check the temp of the coolant in the radiator. And Having something over the rad hole (at least a shop rag or something) might be wise - on some cars coolant comes flying out pretty good.

The air in the system is the place to start. You can remove the ECT to help purge air if you think it was deep. Using a stat with a jiggle valve helps a lot with bleeding.
Good luck.

 

[savegoodautonfg]

Try this...
Jack the front drivers side of the car up a little. You are trying to elevate the cap of the radiator so that it is the highest point in the cooling system. Then go through the normal process of burping the cooling system.
With the cap off, start the car and let the motor warm up. Remember to never pull the Rad Cap when the motor is hot! I had a Football Coach in High School who did this, and the entire front of his chest and arms were scared from the coolant burns.
Let the motor run for a while and run the heater on max to help purge air from the heater core.

jason

For one my heater core went so i have it bypassed im doing that within the next 2 months. and also im new at this whole mustang thing so i dont know how to burp the cooling system?

 

[jrichker]

.) The secondary power ground is between the back of the
intake manifold and the driver's side firewall. It is often missing or
loose. It supplies ground for the alternator, A/C compressor
clutch and other electrical accessories such as the gauges.
Any car that has a 3G alternator needs a 4 gauge ground wire
running from the block to the chassis ground where the battery
pigtail ground connects. The 3G has a 130 amp capacity, so
you wire the power side with 4 gauge wire. It stands to reason
that the ground side handles just a much current, so it needs to
be 4 gauge too.

If that doesn't fix it, replace the gauge sender.

 

[woodyy24]

For one my heater core went so i have it bypassed im doing that within the next 2 months. and also im new at this whole mustang thing so i dont know how to burp the cooling system?

ok say you have a bucket of water and a cup, if you put the cup in the bucket upside down and push to the bottom whats trapped inside? AIR, how do you get the air out? make a hole near the top.

sometimes when filling the cooling system air get trapped near the top of the engine in the heads and intake (this is true of any car) an easy way to get the air out is loosen the temp sensor thereby making an escape path for the air.

old ass pic of my engine, the ECT sensor is circled in red. its not a stock intake but its in the same location. (i think)

 

[savegoodautonfg]

.) The secondary power ground is between the back of the
intake manifold and the driver's side firewall. It is often missing or
loose. It supplies ground for the alternator, A/C compressor
clutch and other electrical accessories such as the gauges.
Any car that has a 3G alternator needs a 4 gauge ground wire
running from the block to the chassis ground where the battery
pigtail ground connects. The 3G has a 130 amp capacity, so
you wire the power side with 4 gauge wire. It stands to reason
that the ground side handles just a much current, so it needs to
be 4 gauge too.

If that doesn't fix it, replace the gauge sender.

Ok thanks for the informative reply. Now i have a powermaster 1 wire alternator. so i don't know if this pertains to me?

 

[jrichker]

Ok thanks for the informative reply. Now i have a powermaster 1 wire alternator. so i don't know if this pertains to me?

Yes.

Hopefully you added a 4 gauge wire & fuse to the power side, now you need to add a 4 gauge wire to the ground side. That insures that the ground current doesn't all flow through the undersized stock ground.

For 99% of the automotive circuits, the power and ground wiring need to be the same size. A bigger ground wire is OK, but a smaller one isn't the best plan.

 

[savegoodautonfg]

Yea but how do i do that when, when i got the alternator it came with just one wire i had to connect to the battery. i thin its 8 gauge. and for the ground i did'nt touch anything with the ground.

 

[savegoodautonfg]

Well i found out one thing the hose that goes from the bottom of the overflow tank to the top where the radiator cap is. at the top part there is a slice in the tube. could this be anything?

I'm going out right now to change the hoseing.

 

[jerryD]

in the pic above, the sender circled in red is the temp sender for the gauge. the ECT would be on the heater heater tubes on the passenger side of the intake.

if you are going to have the coolant low enough to change the sender, now would be a good time to add a aftermarket temp gauge on there, cause we all know the factory gauges are iffy.

 

[The Shape]

Since the engine is newly installed, burbing the system from air is probably going to be the thing to do. But I once changed my intake gaskets on my GT and the temp gauge was working fine before. As soon as I cranked the car it pegged the gauge to the top. I don;t know what happened to the sender but it died on me just like that. Less than 5 bucks I was good as new though.