Temp Sending Unit
Thread Starter
Instructor
Joined: Oct 2003
Posts: 135
Likes: 0
From: Phoenix AZ
Temp Sending Unit
Problem: Temperature rizing to 240+ quickly, few minutes.
Its not the antifreeze, not the thermostat, not the fans, not the hozes, the engine is not even hot to the touch. I used a temp gun (point and measure) at many points in the engine and radiator hoses and they are all low, around 100 +. Even the exhaust was only a little over 100.
I'm thinking its got to be the temperature sending unit. Can anyone give any advice on finding this and fixing this. Or if it can be anything else.
Its not the antifreeze, not the thermostat, not the fans, not the hozes, the engine is not even hot to the touch. I used a temp gun (point and measure) at many points in the engine and radiator hoses and they are all low, around 100 +. Even the exhaust was only a little over 100.
I'm thinking its got to be the temperature sending unit. Can anyone give any advice on finding this and fixing this. Or if it can be anything else.
Racer
Joined: Mar 2006
Posts: 270
Likes: 0
From: los altos ca
air might be traped in your engine..
check your heater does it still work properly? if it does not blow out hot air then your ac lines may have clogged causing air to build up inside the engine....this happened to me once, I cleaned out my ac lines with a pipe cleaner, and ran the engine hard to push out the air...what happened was the air was trapped where the temp sensor was in the cooling system, given that air heats up much faster than the coolant, the engine gets a false indication of real temp....hope this helps...
Thread Starter
Instructor
Joined: Oct 2003
Posts: 135
Likes: 0
From: Phoenix AZ
I changed the temp sending unit. Its now runs a little different, but still has problems. The temp will rise like before, but will fluctuate. For example, it will go to 240, after a couple of minutes it will start to drop to 220, then up to 230, then 215, then 240, ... The temp will change every 3-5 minutes.
The heater works fine.
Whats left? Could this be the gauge itself, air in system? Any tips on removing the air out of the system.
The heater works fine.
Whats left? Could this be the gauge itself, air in system? Any tips on removing the air out of the system.
Team Owner
Joined: Mar 2001
Posts: 21,325
Likes: 3,841
From: small town in S.E Pa. PA
St. Jude Donor '03-'04
Have seen several temp sensor failure reports here over the years... not common but would appear to be your problem.. inexpensive sensor, contact gene culley at fred beans a forum vendor. Also have your vin # handy.
gculley@fredbeans.com
gculley@fredbeans.com
Team Owner
Joined: Mar 1999
Posts: 22,025
Likes: 192
From: At the beach in little Rhody
Originally Posted by AZBrewer
Any tips on removing the air out of the system.
I have never tried this, but take the line from the head cross-over off of the throttle body. Hook up a Miti-vac and pull a little vacuum on the block to see if any air comes out. If you keep the hose high, you might be able to get any air if there is some. Honestly though, I have my heads off right now and have inspected the block with a boroscope and I don't think you could trap air in the block.
