mooshie

so the car was running cold and changing the thermostat is easy so I swapped in a new one.

Once done however it didnt fix the problem. Takes a long time to warm up and going down hills it drops down as low as 60ish degrees.

I did a bit of reading on the electric thermostat and some testing on the old one, then decided to unplug the element from the new thermostat and give it a go. It then warmed up quite well and was stable between 86 degrees down hills and light load up to an absolute maximum blip of 98 degrees when parked and running back in the garage. Fan is coming on at about 96/97 degrees and gets back down to about 92 before switching off again- all looks good, except.... what about that electrical connector?

From what I read it directs coolant from the engine back to the engine or to the radiator depending on certain conditions but the basic functionality of the thermo is mechanical as demonstrated above. I am concerned that I might do some damage to the motor or cause issues with this unplugged.

Anyone got any feedback or insight?

Cant seem to find this particular issue anywhere. Ambient temps are in the low teens Celsius while doing all of this. On a side note and possibly related, the car has a 1.17 amp draw when parked up and all switched off and just today while doing all this testing a 'check oil level at next fuel fill' message came up on my dash repeatedly (oil is fine- right at maximum and just serviced 1000km ago)

Thanks in advance and great site!

mtrevelino

What year? What engine? Where are you located?
Mike T.

mooshie

sorry, E280 Estate. 2006 Australian Delivered. M272 3.0L 6cyl 170kw variant.

Just got back from a little test run and watching coolant temps using an OBDII sender and my phone. Saw a big spike as I went on to the freeway and it was warming up. 70 degrees then went to 90 as I accelerated and then up a gradual incline at about 70% load it got up to 112 degrees

Had to back off due to speed limit change (bad weather, variable signs/limits) and all of a sudden it plummeted back down to 92 within about 15 seconds. It was above 105 for about 20 seconds in total. Gauge on the dash stayed at around the 90 section the whole time.

I wonder if that little element in the thermostat housing would have opened the flow back around the block and stopped that spike?


No other issues on the drive.

mooshie

Tried a start from cold this morning and same thing happened- got too hot then came back to 90ish quickly.

Would love some other experiences/info on this and any ideas on a fix

note that all of the above are with that element disconnected. Went for a drive tonight with the element plugged back in and its not getting up to temp again. Warmed it up to 40 in the carport then did the same test run as I have been doing. It got up to 57 under load on the freeway and then stabilised there. maximum was 60 and minimum 54 while driving, back under the carport it eventually got to 92 after 10 mins, then I got bored and switched off. .

So it seems the question now is how is the element in the thermostat controlled? I am thinking front SAM which may also explain a couple of the other little issues noted above. Where can IK get one of them from? As I understand it they need to be programmed when installed?

Azeem

What's the ambient temperature when you are test driving. I believe it's winters in Australia.
In South Asia, with Ambient temperature around 35, my temperature guage takes 10 mins to reach 92C.

mooshie

Ambient temperature about 10 degrees C. It gets up to 55ish degrees quickly enough but that's as far as it goes - for some reason it's electronically opening when it shouldn't be.