Changing your thermostat:
I decided I was going to change the thermostat in my 20v silvertop since I was experiencing overheating after driving more than 5 blocks, I knew something weird was going on because my new coolant temp gauge was not increasing at all, essentially the coolant was not leaving the engine to change the reading on my new sensor. I figured it was the thermostat which was stuck closed, causing the coolant to stay in the engine and leading to overheating. Two nuts hold the thermostat cover on, fairly easy to remove. Once off, you can pull the thermostat out along with the black rubber seal. Comparing the old vs new thermostat raised some questions. Why do they look so different? I purchased the new thermostat from Toyota and I was sure I had the correct part number. I test fit the new thermostat but found that it was SLIGHTY too small. I am talking ~1mm smaller in diameter than the old unit, this allowed for some play back and forth when the thermostat was installed. I didn’t like this, so I removed the new unit and put the old one back in. I returned the new unit and am still confused as to which part number is the correct one for the 20v engine.
Note: It turned out that my old thermostat was fine. What happened was that during my engine rebuild, I had stuffed all the coolant openings with shop rags to keep the engine from dripping on my garage floor. I removed all of these rags EXCEPT one at the thermostat. This had effectively plugged the out line for my coolant and caused overheating. Always check your engine over twice after a rebuild!
Changing your thermostat:
I decided I was going to change the thermostat in my 20v silvertop since I was experiencing overheating after driving more than 5 blocks, I knew something weird was going on because my new coolant temp gauge was not increasing at all, essentially the coolant was not leaving the engine to change the reading on my new sensor. I figured it was the thermostat which was stuck closed, causing the coolant to stay in the engine and leading to overheating. Two nuts hold the thermostat cover on, fairly easy to remove. Once off, you can pull the thermostat out along with the black rubber seal. Comparing the old vs new thermostat raised some questions. Why do they look so different? I purchased the new thermostat from Toyota and I was sure I had the correct part number. I test fit the new thermostat but found that it was SLIGHTY too small. I am talking ~1mm smaller in diameter than the old unit, this allowed for some play back and forth when the thermostat was installed. I didn’t like this, so I removed the new unit and put the old one back in. I returned the new unit and am still confused as to which part number is the correct one for the 20v engine.
Note: It turned out that my old thermostat was fine. What happened was that during my engine rebuild, I had stuffed all the coolant openings with shop rags to keep the engine from dripping on my garage floor. I removed all of these rags EXCEPT one at the thermostat. This had effectively plugged the out line for my coolant and caused overheating. Always check your engine over twice after a rebuild!