E39 530d - running cold

[Solo Man]

I recently became the proud owner of a 2003 E39 530d auto. (192000km) Noticed on a long trip that when the temp outside is very cold (like in mid winter), the temp gauge needle will come down a bit from the normal centre position, especially when going downhill.
I have replaced the thermostat with a new one from BMW, but no difference. When it is cold outside, the needle will still fluctuate towards cold, right up to about one quarter position. (The "old" thermostat looked like new when i took it out). I have read on a UK forum that apparantly there is another thermostat somewhere else on this engine, but can't find the forum or the thermostat on realoem. Can anyone please help with this problem? Thanks

 

[Truvalu]

Welcome and enjoy!!

Please post some pics of your ride...

I am not sure if one should be seriously alarmed at the motor running colder, especially when going downhill. Should that not be normal?

I would rather worry if it went the other way...

I have no doubt that you will get your answer on this forum.

 

[andrewbuch]

My E36, When doing long trips when its cold the temp gauge also drops.. Dont think you need to worry about it

 

[Solo Man]

Thanks for the quick response. Regarding the E36, I also have a 1994 316i with the M42 motor which I bought about a year ago with 334000km on the clock. The motor runs like a swiss watch. It had the same problem, coming down Sir Lowreys Pass the temp gauge would come down. Replaced the thermostat and bingo, needle is back to normal all the way.
So, my mind is not at ease yet.

 

[andrewbuch]

My e36 1992 316i has 35000km on the brand new engine replaced by bmw so thermostat should be good. Mine only happens on long trips when very cold outside.

 

[msm]

My 3.0d X5 does the same thing on long distance trips when cold outside. Also, think it's normal.

 

[bmwe34]

My audi a4 runs cold when i use the aircon even if its 31 degrees outside...???

 

[WerriesM5]

The temp can drop slightly but not down to 1/4 or below, the other thermostat is ontop of the EGR cooler, the pipe that runs from the exhaust manifold infront of the engine to the intake. Part nr 14 is the EGR thermostat
Please note!! not all E39 530d's have the cooler on the exhaust pipe.

 

[Philip Foglar]

Welcome to the forum!

Must remember that first of all a diesel engine (BMW in particular) are very efficient meaning they don't waste much heat (energy). I remember the original E46 320d that CAR tested all those years ago noted this too and indicated that as a result the interior heater was aided by an electric heater which from what I understood would help the engine get up to temperature in the cold mornings as well as warm the interior...

But petrol or diesel, modern cars cut off fuel supply to the engine when in overrun closed throttle situations as in going down a long hill like Sir Lowry's Pass. So I would think that to see a drop in engine temperature should be normal, especially if it is could outside.

At least your car has a temperature gauge, my E90 330i only has an overheat warning, and the only way to see when the engine is up to normal running temperature is to constantly check the oil level on the computer which will only register a result once up to temperature...

Yep, post some pics! :thumbsup:

 

[andrewbuch]

My girlfriends corsa does that. When you put the aircon on it turns the fans on so keeps the water temp low. Good thing to know as if it starts running hot turn the aircon on and it should cool it down.

My audi a4 runs cold when i use the aircon even if its 31 degrees outside...???

 

[Solo Man]

I am not a computer wizzard. How do i post pics?? In detail please!!

---

WerriesM5, thanks for the info. Had a look, mine has the watercooler on the boostpipe. It seems though that if that thermostat would stay shut for example, it will not be a major disaster, especially now that Summer is here. Engine temp will probably be high enough not to cause damage?

 

[Philip Foglar]

If you don't already have a Photobucket account you can register for free and then upload your pics there. Then all you need to do is copy the

tag for each pic uploaded and paste on your thread here...

 

[Solo Man]

My 530d
http://s841.photobucket.com/albums/zz334/SoloMan7/
Hope this works

 

[Beast_Power]

Have you replaced temperature sensor, Have had different problems on different types of cars in the last year, even on the M adn ended up being a temperature censor's being the main solution to most of the problems. Some problems were not even temperature related.

 

[andrewbuch]

 

[Philip Foglar]

Awesome looking beast!

 

[Solo Man]

Thanks, am really enjoying the diesel torque. On a trip up to Gauteng, four up with luggage travelling at 120 on GPS i got 15km/l (6,7l/100km). Was really pleasantly surprised. On a round trip to Upington last week gave me going up just under 15km/l and coming back, just over 15km/l. I was alone this time, so it seems that with the EGR vacuum disconnected and plugged it did not make much of a difference to the consumption or performance.

 

[Philip Foglar]

On the open road these diesels are scary good at being economical! But even my 330i is pretty good for what it is and being a petrol - went to Montagu a while ago also four up and the average there was 8.2 l/100 km (12.2 km/l) and when we got back to Durbanville it was 8.4 l/100 km (11.9 km/l). And this was mostly sitting at or just over the speed limit based on what the GPS was showing...