_ethrty-Andy_ 2132 Report post Posted August 22, 2012 (edited) so the car is not warming up ever. i replaced the gauge sender first because i thought its probably that which is the issue. i tested the wire by grounding it and then applying 12V fromt he battery and gauge movs as its supposed to. put the engine all back together and still minimal gauge movement. the needle is about 1mm off the bottom of the scale when the car is totally off, and goes about a mm past the lowest line when "hot". only time i have EVER seen it go further is when it was idling in my friends driveway charging her battery for about 5 minutes, it was just past the max-blue mark then. i dont take the car for long drives often, but on the weekend drove from Karori to my house (about 50km or so) so should definately hot. I decided i would check the temperature using my multimeter which has a thermister attachment so immediately after getting home i took the radiator cap off and apart from a slight hiss of pressure no difference to if the car had sat for 3 days etc. multimeter read 55degrees celcius after it adjusted. I didnt believe it so boiled the kettle with the thermistor inside and seems to be fairly accurate! I also drove to see belicose and back in this car a few months back with a trailer on the back, nonstop drive, was at his for about 10 minutes then all the way back. NEVER left the blue. coolant mix is 30/70 and havent had to top up water since. water pump looks reletively new and belts need replacing but shouldnt cause this issue anyway. radiator seems to be working fine. thought i wonder if the coolant lines in the block are clogged so maybe the block is overheating, but there is no loss of power when ready, compression is remarkably very close to when the engine was new etc. am i right in thinking this is the thermostat thats jammed open? surely it would still eventually get hot coolant though? better running too cold than too hot i guess..... but still! Edited August 22, 2012 by _Ethrty-Andy_ Quote Share this post Link to post Share on other sites
Jono51 59 Report post Posted August 22, 2012 so the car is not warming up ever. i replaced the gauge sender first because i thought its probably that which is the issue. i tested the wire by grounding it and then applying 12V fromt he battery and gauge movs as its supposed to. put the engine all back together and still minimal gauge movement. the needle is about 1mm off the bottom of the scale when the car is totally off, and goes about a mm past the lowest line when "hot". only time i have EVER seen it go further is when it was idling in my friends driveway charging her battery for about 5 minutes, it was just past the max-blue mark then. i dont take the car for long drives often, but on the weekend drove from Karori to my house (about 50km or so) so should definately hot. I decided i would check the temperature using my multimeter which has a thermister attachment so immediately after getting home i took the radiator cap off and apart from a slight hiss of pressure no difference to if the car had sat for 3 days etc. multimeter read 55degrees celcius after it adjusted. I didnt believe it so boiled the kettle with the thermistor inside and seems to be fairly accurate! I also drove to see belicose and back in this car a few months back with a trailer on the back, nonstop drive, was at his for about 10 minutes then all the way back. NEVER left the blue. coolant mix is 30/70 and havent had to top up water since. water pump looks reletively new and belts need replacing but shouldnt cause this issue anyway. radiator seems to be working fine. thought i wonder if the coolant lines in the block are clogged so maybe the block is overheating, but there is no loss of power when ready, compression is remarkably very close to when the engine was new etc. am i right in thinking this is the thermostat thats jammed open? surely it would still eventually get hot coolant though? better running too cold than too hot i guess..... but still! yip thermostat Quote Share this post Link to post Share on other sites
polley 916 Report post Posted August 22, 2012 surely it would still eventually get hot coolant though? nope, especially not in cold weather. with full flow through the radiator the engine cant heat the water enough. Quote Share this post Link to post Share on other sites
Greg111 13 Report post Posted August 22, 2012 Sit on the go pedal whilst stationary, see if it goes up then, if so, go for a drive and watch the needle go back down-thermostat. Quote Share this post Link to post Share on other sites
polley 916 Report post Posted August 22, 2012 Just replace it, its like $50 and its good maintenance. Quote Share this post Link to post Share on other sites
hotwire 352 Report post Posted August 22, 2012 ^^^^ Surely diagnose the problem first - easy enough to do. Not disputing your logic in this case but I always like to confirm a problem. Quote Share this post Link to post Share on other sites
_ethrty-Andy_ 2132 Report post Posted August 22, 2012 Sweet have already priced it with Gavin sounds like a nobrainer! Will post back either way next week with result Quote Share this post Link to post Share on other sites
_ethrty-Andy_ 2132 Report post Posted August 25, 2012 wohoo all fixed. was the original BMW 1989 thermostat! pics etc Visit My Website Quote Share this post Link to post Share on other sites
