Engine temp sensor (1 Viewer)

[aroq]

Hey all,

So I just recently had the timing belt changed and the water pump. I have now vowed to take this task on myself from now on....but never the less, I have an issue since the work was performed.

My temp gauge has been acting up. It stays pegged at the bottom until warm, then bounces until fully warm. In that timeframe, when I rev it , the needle drops to the floor. Is this an indication of the ECT sensor going out or do I have other issues?

2001 LC with 325k on the clock. No Idea when the ECT was last replaced, probably factory.

thanks

 

[nissanh]

Does your RPM come to about 650 to 700 after warming up? If it stays at around 900-1000, then the coolant temp sensor that feeds the ECU has gone bad. I own few toyota trucks and my first experience in failing coolant temp sensor was in my LC (2000). Installed a sensor off of my 92 corolla and the rpm started staying at 650-700 range.

If the needle fluctuates, it can be of few issues. (a) May be there is a trapped air bubble after the T-belt job: Fix, when engine is COLD (NEVER when warm or hot), remove the radiator cap and start the engine and wait for it to warm up on its own. If coolant level goes down, add more coolant. (B) a loose connection at the temp sensor that feeds the needle in the dash. I recently experience this on my 92 corolla. Thought a failing temp sensor, so I pulled the wire plug and cleaned the contacts and replugged it. It's been few days and the needle works as normal. (C) a faulty sensor; use and oem sensor.

 

[flintknapper]

There is a a sender and sensor right together at the front left of the engine up near the intake. The green one is the sensor for the ECU and gray one is the sending unit to dash gauge. Check the wiring and connections on both. Particularly the gray one, it is a single wire and the connection is rather fragile.