320D Possible Thermostat Issues?

[hazzer321]

My car hasn't been reaching the correct temperature in recent times and i have noticed a drop in MPG, i realise now winter has set in it will take longer for the car to warm up and mpg will drop a bit but tonight i started the car from completely cold and it took nearly 45 minutes to reach 73 degrees whilst idling and no heating on. (picture below)

this was the temperature after driving the car about 7 miles 68 degrees

i have already changed the EGR thermostat but this doesn't seem to have made a difference, so im wondering if it is going to be the main thermostat.

how long should i expect to wait for my car to get to temperature from idle?

what temperatures should i expect whilst driving?

one final question is, are there any DIY guides online as if it is the thermostat ill probably do it my self

thanks for your time

[Ashpotter1991]

Mine does the same , I have being told that its the main stat mine stops at about 62 and will only ever go up to half way in heavy traffic stop starting , as for the guide I'm sure there is one its a case of taking the fan out for access , draining the coolant ect swapping the stat and re bleeding coolant

[Rich_D]

same with mine, changed the EGR thermostat and it made no difference, so I've bought a main one, need to get it fitted, lots of people on here are having the same problem

it will take forever to warm up at idle only, but when driving it should get into the 80's in a few minutes

there is a DIY on another forum, will find the link and post it on here

Edited December 16, 2012 by Rich_D

[Ashpotter1991]

http://tis.spaghetticoder.org/s/view.pl?1/04/53/62

[hazzer321]

Mine does the same , I have being told that its the main stat mine stops at about 62 and will only ever go up to half way in heavy traffic stop starting , as for the guide I'm sure there is one its a case of taking the fan out for access , draining the coolant ect swapping the stat and re bleeding coolant

whats your MPG like then as mine has reduced not massively but enough to notice?

thanks for the link

[Ashpotter1991]

Mine has been like it since I got it .. Only had the car about 6 months . As for the mpg I've all ways thought it wasn't excellent but then I do give it some beans now and again plus it's being remapped so I haven't anything to compare to. But they are the symptoms of a bad thermostat , bad temp, bad mpg ect . I will be attempting this soon and probably change the fan belts and tensioner at the same time while I'm down there . Just finding time to do it but if I get to it before you do I will share my experience of the job ( where I f**ked up)

[snipey]

Definitely main stat needs doing! My 320d is up to temp after about 5 miles (start-stop through traffic) or about 3-4 miles if I get on the motorway.

Bear in mind this time of year will see a drop in MPG because of driving through the denser cold air AND because a lot of people will fire the car up to let it defrost before driving off!?

[james@ M Developments]

They also put adatives in diesel at this time of year to prevent it freezing, this drops economy.

Certainly sounds like a main stat issue, i did mine not too long ago and noticed a significant improvment in warm up time, not too bad a job, just involves removing the EGR cooler.

Edited December 17, 2012 by james@msd

[deano1986]

mines the same......been meaning to do it for 12 months now....strangely when i park on a hill, facing down (bonnet down, rear up), the car heats up much much quicker

[Jason seery]

years old I know but for anyone new reading  .Its the main thermostat not the egr thermostat but change both anyway at the same time, mine use to take ages to get up to temperature but then drop down to just above the blue mark and then at idle sit at 12 o clock position, changed the egr just to chance it but no luck then changed the main one and car warms up after a few miles and doesnt budge from 12 o clock positon, mpg improved

Edited June 7, 2020 by Jason seery
update

[tom47]

I replaced egr and main, temp today at outside of 0c was showing 72c and did drop to 68c..

 

I chose an average main stat not oem....

 

Im going to replace the main stat again, what was the OEM brand fitted to the car ?? MPG is not good, dropped to 38mpg which is very bad, any ideas

 

It was all bled properly btw

 

thanks for your help

[dontpannic]

Definitely sounds like the stat still - I used genuine BMW for the EGR stat (however I've now completely removed the EGR and cooler. For the main stat I've used Circoli. Takes around 5-10 miles to get up to 86c and stays there. That's a 330d though, the 320d might take a different time.