Arctic Chat

grandam2006 · 12-28-2007, 12:53 PM

How do you tell if your coolant temp sensor is bad?

What will happen if it is bad? sled not run right, or rich?

catryder · 12-28-2007, 05:04 PM

Hard to start cold or hard to start when engine is warm. On mine when the engine was warm it tried to give it too much fuel and tried to flood it when trying to re-start it. The sensor reads coolant temperature to tell the computer how much fuel is needed to make it run correctly. Just like a choke.

**kev** · 12-28-2007, 05:10 PM

On my 95 and 99 they are not that sophisticated. All it does is turn on the light on the dash. If it's bad you might never know. I don't know of any vehicle that uses the coolant sensor to regulate fuel flow. Most cars have many other sensors for that.

catryder · 12-30-2007, 11:23 AM

Had a 98 Dodge Ram 360 EFI come into the shop last Friday for repair because when it sat outside in the cold it would flood itself out trying to start it. Yet when you plugged the block heater in it would start after the coolant warmed up. Changed the coolant temperature sensor and that fixed the problem. The sensor was reading the coolant temp. a lot colder than it actually was and was telling the computer to dump too much fuel into it. When an engine is warm it doesn`t need so much fuel to start it and so the sensor takes the coolant reading and tells the computer that. Actually the computer takes the ohm reading from the sensor and the ohms change as the coolant temperature changes. Any EFI engine works the same way be it car, truck atv or sled. That`s why I said the sensor acts like a choke. Hope this explains it better.
As a side note to this the coolant temperature sensor does not affect sled performance other than starting it.

pld0vr · 01-06-2008, 01:34 PM

<div class='quotetop'>QUOTE (kev @ Dec 28 2007, 06:10 PM) <{POST_SNAPBACK}></div>

Quote:

On my 95 and 99 they are not that sophisticated. All it does is turn on the light on the dash. If it's bad you might never know. I don't know of any vehicle that uses the coolant sensor to regulate fuel flow. Most cars have many other sensors for that.[/b]

Not true... pretty much all cars with EFI use a coolant sensor in the fuel algorithm. I have a stand alone system in my car so I know how this works...

If the engine is cold, the fuel does not vaporize properly and sticks to the intake track, etc, and it needs to be richer, and the car uses the coolant sensor to figure this out.

paintballdude05 · 01-06-2008, 10:24 PM

I thought the ECU took its temp from the outside air not the temp. of the coolant to regulate fuel?

Auggie · 01-06-2008, 10:40 PM

The first part of Kev's statement is true. Disconnect the wire to the temp sensor, start the engine and ground the wire and the coolent light will come on if the bulb is good. The non EFI sensor's are like a light switch, they are either on or off. The only problem with Arctic's coolent sensors is that when they turn on the light its almost too late. I have checked two differant type's and one closes at 248* and the other at 254* and with a 13# pressure cap that is cutting it to close. Do the math.

13 x 3* = 39* + 212* = 251*

So if you have the 248* sensor you may be OK but if you have the 254* sensor the cap will pop and start blowing out coolent before the light comes on. That is not a good thing. I went out and bought a 16# cap.

16 x 3* = 48* + 212* = 260*. Nuff said.

Auggie

paintballdude05 · 01-07-2008, 12:08 AM

Isint the cap rated @ 13 psi? I dont get you're math? On top of that isint the cap suposed to blow before damamge ocours in the system from overpresurisation? Bringing it higher you would risk things poping

. Not arguing here just need a better explication.

insaincat · 01-07-2008, 09:24 AM

<div class='quotetop'>QUOTE (paintballdude05 @ Jan 7 2008, 01:08 AM) <{POST_SNAPBACK}></div>

Quote:

Isint the cap rated @ 13 psi? I dont get you're math? On top of that isint the cap suposed to blow before damamge ocours in the system from overpresurisation? Bringing it higher you would risk things poping

. Not arguing here just need a better explication.[/b]

Well a 13# cap means it will hold 13 lbs. of pressure, a 15# will hold 15 lbs. of pressure. The more pressure in the system, the higher the boiling point. A 13# cap will relieve pressure at or slightly above 13 lbs. of pressure. So a cap really isn't tied into the sensor.

Rick

pld0vr · 01-07-2008, 09:29 AM

<div class='quotetop'>QUOTE (kev @ Dec 28 2007, 06:10 PM) <{POST_SNAPBACK}></div>

Quote:

On my 95 and 99 they are not that sophisticated. All it does is turn on the light on the dash. If it's bad you might never know. I don't know of any vehicle that uses the coolant sensor to regulate fuel flow. Most cars have many other sensors for that.[/b]

On my 94 I have the same system as you and my temp sensor is bad. As soon as I start the sled that light comes on... if I unplug the sensor it goes off.