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I've been having some minor coolant temp issues with my 95 LS400. Two weeks ago I bled the system using a spill-free funnel directly into the water fill at the top of the front water housing. It took about 15 minutes but I was able to get all the air out of the system. Driving around town for an hour or so and my temp starts moving up and down from the normal mid-point. Never reached the red, but did get close - too high for my comfort. I've also noticed small puddles of coolant on the garage floor after sitting overnight, but didn't notice any when out driving around.
So I put it up on the lift today to check for possible water pump leak - Nope. Followed the trail of dried coolant up after removing all the covers and found this. Most of the coolant appears to be coming from the sender. It's been threaded out and cleaned so I could tell if it was damaged.
The sensor hasn't been replaced for the several years I've had the car and it didn't appear to have any leaks. Anyone seen this before?
The other thing I noticed aside from the small puddle, was that the level in the overflow tank has stayed the same. So I pulled it off and the flow out the nipple to the engine was minimal, so I back flushed it with some tubing and water and is better now.
I was also concerned that maybe one of the coolant passages in the engine is blocked . I loosened the left drain plug on the block and used low water pressure at the fill plug to flush the system, so nothing obvious there. The thermostat (a couple years old) has been removed and tested and still functions properly. With all the hoses removed I also back-flushed the radiator & was getting good flow there.
What else am I missing that could cause pressure to build up on the engine side and not draw coolant from the reservoir? None of my manuals show the complete cooling system with all the coolant paths so I'm hoping someone's BTDT.
TIA,
Gerard
Last edited by 3d914; 11-23-17 at 04:34 PM.
Reason: spelling
I've been having some minor coolant temp issues with my 95 LS400. Two weeks ago I bled the system using a spill-free funnel directly into the water fill at the top of the front water housing. It took about 15 minutes but I was able to get all the air out of the system. Driving around town for an hour or so and my temp starts moving up and down from the normal mid-point. Never reached the red, but did get close - too high for my comfort. I've also noticed small puddles of coolant on the garage floor after sitting overnight, but didn't notice any when out driving around.
So I put it up on the lift today to check for possible water pump leak - Nope. Followed the trail of dried coolant up after removing all the covers and found this. Most of the coolant appears to be coming from the sender. It's been threaded out and cleaned so I could tell if it was damaged.
The sensor hasn't been replaced for the several years I've had the car and it didn't appear to have any leaks. Anyone seen this before?
The other thing I noticed aside from the small puddle, was that the level in the overflow tank has stayed the same. So I pulled it off and the flow out the nipple to the engine was minimal, so I back flushed it with some tubing and water and is better now.
I was also concerned that maybe one of the coolant passages in the engine is blocked . I loosened the left drain plug on the block and used low water pressure at the fill plug to flush the system, so nothing obvious there. The thermostat (a couple years old) has been removed and tested and still functions properly. With all the hoses removed I also back-flushed the radiator & was getting good flow there.
What else am I missing that could cause pressure to build up on the engine side and not draw coolant from the reservoir? None of my manuals show the complete cooling system with all the coolant paths so I'm hoping someone's BTDT.
TIA,
Gerard
Replace the sensor AND crush washer.
Use OEM for best results.
Present your image to the dealer to be sure you receive correct sensor..
11-23-17, 04:33 PM
Leaking Temp Sender - Anyone seen this?
