2003 Lexus IS 200 Loosening water overflow tank

2003 LEXUS IS 200
90,000 MILES • 2.0L • 6 CYL • RWD • MANUAL
Avatar
MBARTIS200
  • MEMBER
  • 3 POSTS
Hi, I have a lexus is200. Aslong as the overflow tank is full it run fine and stays at temp, but when Check the overflow tank after going anywhere it's almost emty. I have plugged it in and it come up with "engine coolant temp malfunction" while plugged in I noticed that them temp sat at 70-80c but when ignition is off it drop to -50 any ideas where to start. Engine temp sensor, thermostat? Many thanks Matt.
May 7, 2014 at 12:12 PM
Advertisement
Avatar
JACOBANDNICKOLAS
  • CERTIFIED EXPERT
  • 110,175 POSTS
Where is the coolant going? Is it leaking? Is there white smoke from the exhaust? Have you checked the engine oil to see if it is mixing with it?
May 7, 2014 at 6:46 PM
Avatar
MBARTIS200
  • MEMBER
  • 3 POSTS
It's not mixing with oil I don't think no mayo on oil cap and water is clean in radiator. I can't see any leaks on pipes only small amounts off water under the overflow pipe, I did notice that the fan do kick in sometime even when not warm?
May 8, 2014 at 1:37 AM
Advertisement
Avatar
JACOBANDNICKOLAS
  • CERTIFIED EXPERT
  • 110,175 POSTS
How much coolant do you lose each time you drive it?
May 8, 2014 at 5:04 AM
Avatar
MBARTIS200
  • MEMBER
  • 3 POSTS
Just over 500ml, I tried an airlock test this morning and seem to have help using little water after 10 mile run, Iv also replaced the pressure cap I the radiator as it didn't look great. Do you think a faulty pressure cap could push the pressure in expansion tank and down overflow pipe as the radiator always seem full. Thanks matt
May 8, 2014 at 5:34 AM
Avatar
JACOBANDNICKOLAS
  • CERTIFIED EXPERT
  • 110,175 POSTS
It could be a problem. Have you pressurized the cap to test it?
May 9, 2014 at 7:30 AM