91 overheating, I'm stumped
#16
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#17
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Have the system pressure tested, it will show if you are actually loosing coolant and if it's in or outside of the motor, it'll give you a better theory to work with. If the pressure tester holds the amount of pressure on the cap, usually 13-16 psi, for 10 mins, your good to go. It is normal to lose a few psi after a few pumps because it's likely there might be a faint amount of air left in the system.
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This will sound absolutely ridiculous,but please try it. Take the car and warm it up then drive it down the road like a maniac and lock the brakes up while nose diving the car watch the gauge. If it goes down ive got some really crazy info for you only seen it once tho. Also how well does the heat work? when you do the nose dive the the heat temp icrease at the vent substatialy?
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SO what happened? I'm having overheating problems as well. Replaced fans and thermostat with no resolve. I don't want to change the water pump but sounds like that's the culprit.
#21
I changed the thermastat, anti-freeze and also changed the radiator cap and my overheating problem was solved...I agree that you should get the system pressure checked as well....
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Im my experience with over-heating if you get top the 4th line and don't shut it down, it will stay pegged on red until something blows. From the sound of it your guage is not accurate.
Replace all coolant temp senors, drain and flush, note to do a full flush, not just the radiator, the 1st gen LS has three coolant bleeders. the one on the radiator, then one on each lower bank of the block. They are a 10mm bolt. Hard as hell to get to. Refill from the top of the thermostat housing, not the reservoir. Make sure you are on level ground too. Refill with toyota red or expect your cooling system to give you more problems than you need. If you still have problems, have the radiator removed and taken to a specialist. It could be clogged. I had mine unclogged in a day for $79, made a huge difference.
Replace all coolant temp senors, drain and flush, note to do a full flush, not just the radiator, the 1st gen LS has three coolant bleeders. the one on the radiator, then one on each lower bank of the block. They are a 10mm bolt. Hard as hell to get to. Refill from the top of the thermostat housing, not the reservoir. Make sure you are on level ground too. Refill with toyota red or expect your cooling system to give you more problems than you need. If you still have problems, have the radiator removed and taken to a specialist. It could be clogged. I had mine unclogged in a day for $79, made a huge difference.
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