Change Engine Coolant Sensor
Thread Starter
Instructor
Joined: Jan 2012
Posts: 108
Likes: 5
From: Lawrenceville NJ
Change Engine Coolant Sensor
I have a stock 1994 base coupe with the LT1 engine and automatic transmission. The analogue engine coolant gauge doesn't work. When I had the car checked out I was told that the temperature sensor was damaged. I think I can change this myself. I can see the sensor on the engine between the spark plugs. Is there any advice on how to remove it? Also, do I need to drain the coolant before I do this? Any help would be appreciated. I do have the fsm manuals but could only find a passing mention that this sensor even existed.
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
Make sure it's not the Display first. Grounding the reference (or wire) should peg the gage hot and when it's not touching anything, it should be cold.
It would probably help to drain the radiator or system below the heads because what's ever above that hole is going to run out when you remove the Sender. Trying to screw a new one in with coolant pouring out of the hole isn't wise - you could strip the threads if you rush the job - and you want a dab of Locktite or Sealer on the threads anyway (some come with it).
It would probably help to drain the radiator or system below the heads because what's ever above that hole is going to run out when you remove the Sender. Trying to screw a new one in with coolant pouring out of the hole isn't wise - you could strip the threads if you rush the job - and you want a dab of Locktite or Sealer on the threads anyway (some come with it).
Le Mans Master
Joined: Aug 2005
Posts: 7,392
Likes: 216
From: Merritt Island, FL
Make sure it's not the Display first. Grounding the reference (or wire) should peg the gage hot and when it's not touching anything, it should be cold.
It would probably help to drain the radiator or system below the heads because what's ever above that hole is going to run out when you remove the Sender. Trying to screw a new one in with coolant pouring out of the hole isn't wise - you could strip the threads if you rush the job - and you want a dab of Locktite or Sealer on the threads anyway (some come with it).
It would probably help to drain the radiator or system below the heads because what's ever above that hole is going to run out when you remove the Sender. Trying to screw a new one in with coolant pouring out of the hole isn't wise - you could strip the threads if you rush the job - and you want a dab of Locktite or Sealer on the threads anyway (some come with it).
Trying to rush the job, especially with aluminum heads, is a bad idea. It only takes a few minutes to open the radiator petcock and drain out enough coolant to prevent leakage when you remove the old sender.
Last edited by VetteMed; Aug 12, 2012 at 11:01 PM.
Instructor
Joined: Dec 2011
Posts: 136
Likes: 3
From: pittsburgh pa.
KEEP THE OPTISPARK DRY!!!!!!!!!!!! i dont know if yours is like my 92 , but you have to bleed the air out of the system when you refill it. mine has 2 bleeder valves 1 on thermostst housing and 1 on front of throttle body.
Instructor
Joined: Mar 2012
Posts: 116
Likes: 0
From: South Lake Tahoe CA
I would drain the coolant at the radiator but also take out the knock sensor on the passenger side to drain that side of the engine, then remove the sensor, should be either a 3/4" wrench/socket or 13/16". No need to worry about silicone but make sure the threads in the head are dry and clean. Re-install, add coolant, and test.
