Gohn 59 Posted November 12 mines a TD converted from an Si (so Si radiator and loom/dash) had a few things going on with my coolant system for a couple of weeks: the low coolant LEVEL warning light has been showing on the dash (but its not low and the system has been bled) and also, the TEMP needle seems to have dropped from where it used to sit when at operating temperature - replaced the thermostat (83deg) - repaired both wires from my coolant level sender which had rubbed exposing wires - and have replaced my coolant level sender now also the low coolant LEVEL dash warning light has now gone but the needle on my dash is still showing the engine is running at a lower operating TEMP the operating temp has always been very consistent Share this post Link to post Share on other sites
welshpug 1,608 Posted November 12 Does it get to 83 and stay there? Share this post Link to post Share on other sites
Gohn 59 Posted November 12 until a few weeks ago the needle would steadily increase until it was nudging the 4th mark from left so just under it, then it would sit there very consistently in the last few weeks it sits just over the 3rd mark or at halfway 3rd to 4th mark dont have any digital temp guages to check what the engine or thermostat is at in degrees Share this post Link to post Share on other sites
DamirGTI 312 Posted November 12 Both thermostat of the same 83C rating ? (there's 80C , 82C , 83C and 88C for TD) replaced thermostat gaskets also along with the thermostat ? .. filled up with fresh coolant 50-50% mix or old reused ? XUD/XUDT uses dual/bypass type thermostat , need to be cautious so you don't mix it with the ordinary/conventional type thermostat . Any change in the ambient temp. down under recently ? Also , could be cooling fan kicking in-out (because of the some wiring/relay fault) at low speed while driving without you noticing/hearing it . Have an IR thermometer ? if so check/measure on the head around thermostat housing , and top and bottom radiator hoses and compare with the reading on the dash . Coolant temp. gauge goes up in 10C increments , starting from 50C to the 110C : Share this post Link to post Share on other sites
Gohn 59 Posted November 13 yeah D the thermostat that was replaced was only 3years old and 83deg the new thermostat is identical 83deg. both OE peugeot thermostat gasket rubber seal ring and thermostat housing gasket both good and re-used coolant about 40% mix with distilled water, 1yr of a 7yr lifespan, reused summers coming here so its just getting hotter week by week changed thermostat just to rule it out as it doesn't seem likely cause maybe go back in and replace both gaskets tomorrow maybe the temp sensors on the thermostat housing need replacing ? at least one looks like it was clunked in transit before it got to me why is there a temp sensor (the rear screw in sensor with Red ring) and a temp sender (front with black ring) ? if your guage degrees are accurate to my guage marks then today the operating temp sat mostly about 75deg and it fluctuates from say 79 down to about 71, in town its lower than highway the lower temp and the fluctuation are both different to normal Share this post Link to post Share on other sites
petert 540 Posted November 13 (edited) Side issue, might be related. The thermostat needs to match the fan switch. ie both 83. The original Si will be more like 95-97. ie the one in the radiator. Edited November 13 by petert Share this post Link to post Share on other sites
Gohn 59 Posted November 14 great thanks, had no idea had noticed a few years ago that the rad fans seemed to kick in much later than expected anyway, went and had a look at the catalog to order the correct part but it confused me (not for the first time ) not sure but doesn't the diesel and Si have a one speed fan, while the GTi has a two speed fan ? still couldn't decipher when the fan kicks on and off in either the GTi , Si, or diesel first pic's the petrol fan switch options: second's the diesel fan switch options: my guess is 126444 although it doesn't have any temp ratings mentioned (the XUD7T usually came in a car with air conditioning which would suggest the correct part is 126445 but the Si body its now in has A/C removed and the Si only has a one speed fan anyway so #126444 should match up to the 83deg diesel thermostat and be what I need ? Share this post Link to post Share on other sites
petert 540 Posted November 14 Si definitely has the two speed fans, identical to Motronic DKZ GTi. Share this post Link to post Share on other sites
welshpug 1,608 Posted November 14 fan thermoswitch 1264 44 is 93/97 -88/92, post 1990 style blue plug with purple ring, 1264 45 is the red ring post 90 sensor, standard on the single fan two speed gti. Share this post Link to post Share on other sites
petert 540 Posted November 15 Does your car have one fan or two? Are there three relays controlling the fan(s)? From my experience, all Aust delivered 205’s had AC. Thus all 205’s had two fans and three relays, to give either slow (fans in series) or fast (fans in parallel). Jetronic models had positive controlled relays, Motronic had negative controlled relays. If your car isn’t as described, it’s been butchered. The fans have nothing to do with the temp sender or temp gauge. They’re totally independent systems. However, if the thermostat and radiator fan switch don’t match, the engine might never get to operating temp, because the fans are always running. Share this post Link to post Share on other sites
petert 540 Posted November 15 Attached is the wiring diagram for Mi16. The Si (and Motronic GTi with A/C) is basically identical, except that the relays are earthed via 58 and 58A via the radiator switch, rather than H114 (the Bitron controller). Share this post Link to post Share on other sites
Gohn 59 Posted November 16 thanks peter, think I've got a few things sorted, what everyone else already knows is sensor is for the dash temp needle reading sender is to set off the dash coolant temp warning light (at 118deg if I've not read it wrong) replaced to check both ok mines regular Si by the way, two fans with three relays (A/C was removed for more space/better airflow in the engine bay) 21 hours ago, petert said: The fans have nothing to do with the temp sender or temp gauge. They’re totally independent systems. However, if the thermostat and radiator fan switch don’t match, the engine might never get to operating temp, because the fans are always running. appreciate that, had a look anyway 126444 (violet/purple ring) switch is on the car and have a spare 126445 (red ring) which is same but operates fans about 5deg higher range got a $35 infrafed thermometer gun basically my dash needle temp is about 10deg short of reality thermostat's working well, engine operating temp is good temp just isn't making it thru from sensor to the dash needle, not sure why ? check the sensor wire and earths ? Share this post Link to post Share on other sites
