[Mk2] [NA] Low coolant temperature

[DB Mr2]

Hoping you can help guys. Temperature goes from half to around quarter and then back up to half way even after 30 mins driving.
I have bled the system about 5 times over the last month bit still an issue.
Heater works fine and is pumping out warm air ( maybe could be hotter?)
This is always included in the bleeding. The left side of radiator doesn't seem to be getting that hot though?
So now I'm thinking that this could be a thermostat of water pump issue?
Are there tests I can do to determine which?
The coolant was replaced by Toyota at end of summer.
Sorry to bring up another coolant thread but I'm fed up of stinking of coolant and taking of spare wheel every weekend!

[mrfil13]

When my Thermostat was stuck open the temp gauge was always low, if stuck in traffic then it would creep up slowly but then drop once i got moving again.

Toyota thermostat is about £25 so worth a try.

[raptor95GTS]

certainly sounds like the thermostat esp since the radiator isn't getting warm. The rev2 stat is the smaller of the options.

[DB Mr2]

Thanks guys new thermostat is on order, I'll get saving for cambelt kit incl water pump for the summer I think.

[Zeppozen]

have the same problem.

Just had the garage change the thermostat.

looks like temp gauge is faulty im told. I tested the sender on engine to earth but needle on gauge didnt move.

Cant help thinking its still open thermostat tho !!

let me know how you got on as it might save me replacing a new thermostat again!

thank you

[DB Mr2]

I spoke with a friend at Toyota that stated they had this issue with a rip off rad cap, mine was a blitz one from when it was imported so I've changed it over but still an issue. I haven't got round to changing thermostat yet but will update thread when I have with the results!

[Canopus]

To test the gauge, with the ignition on you disconnect the engine temperature wire and earth it. The gauge should then read maximum. The sender units work by progressivley reducing the resistance as the temperature goes up.

Mine was reading low and occassionaly fluctuating betweem 1/4 and 1/2 when one day it just stopped reading. Cost is quite minimal and if you do it quickly you don't loose much coolant. Since I've replaced the sender the temperature gets to half way much quicker. No real change but the gauge is just reading the temperature quicker.

Geoff

[Baker]

lose.

[Zeppozen]

thanks for the help. The test does not move the gauge !!

also there is no voltage from the live wire to the sender? ( when earthed with a multimeter) should there be a voltage ?

ta