Overheating Issue!...Well Maybe

  1. Infrequent Poster Joined: Sep 2007 Newcastle Upon Tyne Posts: 130 Mk1 Silver Vtr
    #1
    Having a bit of a nightmare getting my saxo back on the road but down to this last issue now so any help would be great

    Basically when the temperature gauge gets to about 3mm above the halfway mark my overheating light is coming on but the temp needle is nowhere near the red yet? Any one experienced this before or know what could be causing it?

    It takes the expected time once the cars started to get the temp needle to just over half doesn't rise rapidly or unusually slowly. Once the light comes on everything does feel a little hot under the bonnet so I turn it off fearing the worst the fan doesn't kick in before the point I turn it off either.

    I fitted a new thermostat this morning and bled the system properly and it was doing it before I changed the coolant so I guess air lock and thermostat can be ruled out.

    I was thinking faulty sensor maybe but anyone else had this issue before? or have an idea what could be the problem? Its on a mk2 vtr 2001.

    Cheers!
  2. Saxperience Post Whore Joined: Nov 2010 Kent Posts: 8439 Gen 7 Celica 190.
    #2
    Question one really are keeping coolent with in the engine, also is there any mayo looking oil ?

    Also the engine getting hot when warmed up is very normal lol
  3. Infrequent Poster Joined: Sep 2007 Newcastle Upon Tyne Posts: 130 Mk1 Silver Vtr
    #3
    Lol yeah I was putting it nicely it seems hotter under there than normal once warmed up which is why I've been turning it off.

    Also no sign of mayo oil and coolant I took out this morning was fine no mixing and no white smoke from exhaust.

    Not sure what first bit is asking but theres no leaks anywhere either
  4. Saxperience Post Whore Joined: Nov 2010 Kent Posts: 8439 Gen 7 Celica 190.
    #4
    Well that would suggest a faulty sensor then, but get it compression tested if you can
  5. Infrequent Poster Joined: Sep 2007 Newcastle Upon Tyne Posts: 130 Mk1 Silver Vtr
    #5
    Ok that shouldn't be too hard to sort then which sensor is the one I want to change? I'm guessing the upper most blue sensor in the picture?

  6. Saxperience Post Whore Joined: Nov 2010 Kent Posts: 8439 Gen 7 Celica 190.
    #6
    Yer the coolent temp sensor could always try give the connectors a clean as they could be dirty, worth a try it may say you £10 lol
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  7. Infrequent Poster Joined: Sep 2007 Newcastle Upon Tyne Posts: 130 Mk1 Silver Vtr
    #7
    Right spot on thanks for your help m8
  8. Regular Poster Joined: Sep 2008 Posts: 449
    #8
    The lower blue sensor is for the light

    Im presuming your car is a 3 plug ecu.. As i can see two lambda sensor plugs.

    If it was a single plug ecu then the lower blue sensor also does the guage. 3plug cars the ecu controls the guage

    As you say light comes on early then i would look at the lower blue sensor. I had a simular problem.. But on a single plug car.... Light on but guage normal
  9. Infrequent Poster Joined: Sep 2007 Newcastle Upon Tyne Posts: 130 Mk1 Silver Vtr
    #9
    Still got this issue after replacing the top coolant temperature sensor so you may be right scottie looks like it could be the warning light sensor that needs replacing, sits bang on halfway while driving then after its stood at idle for a couple minutes it rises slightly over halfway and red light comes on, but no fan.

    Can any one tell me at what point on the temp gauge there fan would normally kick in please?
  10. Saxperience Hardcore! Joined: Dec 2007 smurfland. Posts: 17346 Ex saxo owner.
    #10
    Is your fan kicking in?
  11. Infrequent Poster Joined: Sep 2007 Newcastle Upon Tyne Posts: 130 Mk1 Silver Vtr
    #11
    fan isnt kicking in but this may be because its not hot enough if the red light is showing far too early due to being possibly faulty but not sure how high on the temp gauge peoples fans would normally switch on
  12. Infrequent Poster Joined: Sep 2007 Newcastle Upon Tyne Posts: 130 Mk1 Silver Vtr
    #12
    ok assumed the temperature gauge was right and the red light wrong so ran it on longer this time and took it to just below the red and no sign of the fan kicking in so I guess this is knackered

    Anyone know if a knackered fan would cause the red light to come on just after half way up the temp gauge? I'm guessing there both at fault?
  13. Saxperience Hardcore! Joined: Dec 2007 smurfland. Posts: 17346 Ex saxo owner.
    #13
    On a mk2 the ecu controls when the fan kicks in.Take the fan off connect direct to the battery & see if it spins.