I cranked the motor for the first time the other day but I never got a temp reading after a min at Idle. What can I look into besides the sensor and the wire? The sensor is new.
The cooling fans do come on with the AC on but don't come on other wise. I don't think It's over heating but the Headers get pretty hot.

The Hooker LT's are getting really hot? What is going on?
I ran the open headers for the first crank and then threw on the Mufflex y-pipe to help with some back pressure. It will idle fine with the y-pipe on but not very long with open headers. I ran a room fan on the motor as the car ran. I just never got any temp.
There is water in the radiator and block. The electric pump sounds good. The bleeder screws have drained all air in the system. What else may I try?

 

You mean you are not getting a temp reading to your PCM or Dash?

They are two sensors.

1.) Plugs in front of water pump (ECT) and it signals the pcm with the coolant temp. You do not see this one, unless you have a scanner.

2.) Plugs into side of Driver side head, has one wire, and goes to gauge on dash. Normally off about 10-15 degress farenheit to high.

You should definelty see the needle gauge move right after a few 20-25 seconds or so.

 

Sometimes mine will take a little while to rise, like 2-3 minutes. It depends on how warm it is outside.

The headers will always get super hot. They are headers. Seriously though I can drive around the block, come back and cant put my hand near the LT's without them burning my hand.

 

My 383 will idle for several minutes before showing any movement in the temp gague when it is cold at start up. Do you have a scanner to read what the PCM is showing for temp?

 

No, I don't have a scanner. I'd like to have on but I don't know which route to take. There are so many choices out there.

What did you do to protect the plug wire on the Driverside that is real close to the primary?


I didn't see the temp needle move at all not even when turning the key from off to ING or Start/Run. The other needels move a little as the power is sent threw the system. I guess I need to shoot the wiring to check the resistance before changing the sensor since the sensor is new. Im wondering if the coolant has filled the heads yet. Id the T-stat is stuck closed, Is it possible for the sensor to be dry and not have any coolant temp to read?

 

These temp gauge sensor gets ground from contact of the head itself. Make sure you did not use too much silicone or thread sealant on the sensor that will prevent good contact.

Was it working before, maybe the wire is being grounded somewhere, given that wire is very close to the headers. I ziptied it away from there.

Maybe a faulty sensor, check its resistance and use a temp to resistance table to check if it is ok. You can find such table on Injuneer scanmaster write-up. sorry i do not have the link.

 

Is it possible to install the sensor to tight or not tight enought? Would that cause the sensor not to ground itself?

 

Many people including me use to much sealant on the threads of the sensor, therefore preventing the sensor from making contact, or check your engine ground straps. There is one near the coil to the frame and another on the passenger side engine mount / it comes from negative terminal of the battery.

First of all check if the sensor is good, check resistance from the tip of the sensor to a good known ground source. Write the resistance # down and compare it to a resistance to tempature chart. It should match your ambient tempature.

Search for Injuneer (I think I spelled it right) with the search function and look into any one of his posts. Search his posting and the link should be in his signature.

Good Luck

 

i would imagine that after only a minute of idling, you will not see any movement in the temp gauge.

and guess why your headers are getting "very hot". because there is 1000+ degree exhaust throwing though them!!!

 

HA HA you guys are funny. I work on Fighter Jets and I am around hot Engines and exhaust as well as hot oil and hydraulic fluid day in and out. I am used to things being pretty hot but this was so hot that I tapped it with my finger and it dam near burned off my callis from my finger. I was asking because the instructions said to use a external fan when first running the headers because of an increase of heat temps in excess of 1000 or something like that. Know what I mean? James

 

I wouldn't think that the guage would move after a minute of idleing, depends on how warm it is outside. Check to see if your gauge is working, ground out the wire that goes to the sensor and the guage should peg the other side.

If you pull the sensor out, don't drain the coolant at first, take it out and see if the head has coolant in it.

You could have gotten a bad sensor, just because its new doesn't mean anything, I replaced a oil sending unit today and the new one didn't work at all.

the next thing you can do is take the sensor out, plug it up and take a propane torch and quickly heat the it up, the side that goes in the block, this will be the easiest way to see if the whole circut is working. Don't heat it longer than 2-3 seconds, that should be more than enough.

Hope this helps.

Jason

 

Takes more than a minute to get a reading from my guage.
A scanner is an invaluable tool when working on these cars, I learned the hard way if you own a computer controlled car and expect to work on it alot then you need to invest in one, even before mods to tell you the truth.
Makes it SO much easier.

 

Thanks for all the good advice. I am going to work on this problem today. I think I'll check the T-stat first to see if it is working. I will also ground out the wire and check the guage. If that doesn't work I'll remove the sensor and try heating it up with boiling water because I don't have a torch. Thanks For the Ideas. I'll let you all know what happens tonight.

 

Headers get hot merely seconds after starting an engine, thin wall steel tubing with gasses exceeding 1000* F will do that

It takes my car longer than a minute to register any kind of temp on the gauge, especially at idle.

You should be aware that the PCM uses a completely different sensor (in the water pump) than what the dash gauge uses (in the cylinder head). You can completely unplug the cylinder head coolant temp sensor and the car will still run perfectly fine. Take it for a drive when it's together before making the assumption that it's not working right... don't assume it's broke because the headers are getting hot and it's idled for a minute. FWIW I run my car consistently at 170* F and the temp gauge barely registers anything at that temp.

 

OK Here is what I did this morning.
I removed the plug and grounded it out with a jumper wire to a grounding point. The guage and circuit is good because the guage mazed out.
I removed the sensor to check for coolant, in my case plain water for the first few runs to check for leaks and what not. As the sensor came out water leaked out for a few min. So the coolant is going where it needs to go and I assume the T stat is working but havent checked it yet. Do I need to check the T-stat? Could my electric pump be pressurizing the system and causing the water to pressurize the system enough to bleed all the air but not enought to circulate the water?
I tried to heat up te sensor in a hot mug of water boiled on the stove but the guage didn't seam to move. I then tried to ground out the sensor while it was hot to see if that is why I didn't get a reading. The only thing I noticed was when I turned the key after putting it all back together, After I turned the key the needle droped down just a hair.

I beleave the wire and circuit is good and the sensor may be wrong. I'll see if I can get ahold of one today from the dealer.

I still welcome any advice on this or any other situations.
DOES ANY ONE KNOW OF A GOOD SCANNER THAT CAN READ ALL THE INFO FROM THE PCM?