jmcdpereira

Not so simple in my case
the rubber tube was very hard and can not be removed, and the other end was stuck because of the cuff. is a special car: (
What matters is that everything is fine now.

Thanks
jmcdpereira

madein

After couple of weeks after changing both of my thermostats and water pump as well my temperature was reaching 90 degrees only occasionally, almost never. I went to the dealer asking about warranty for those parts, and they said only leave the car to test it, so I have decided to buy new EGR thermostat insted and changed it - of course didn't help. I have longer run than my usual 10 miles in the morning or afternoon about 40 miles with the outside temperature about 8 degrees and the car was mostly about 80 degrees. I'm really confused now, do I need to change the main thermostat again? Or the problem can be somewhere else?

Within 5 minutes and first few miles about 50-60 degrees without any problem, than after an hour still 80 degrees
changed main thermostat, EGR thermostat 2x and still can't reach every time properly 90 degrees.

pszyman

If you have auto or manual gearbox? I read about some thermostat in the auto gearbox but I can't any details on RealOAM

neo61uk

Hi to all

Ive just read every page of this long ongoing topic.
Its great that so many of You guys have fixed Your cars

But to be honest with You
If Your car is running fine with around 85 degress ii is absolutely fine.
Thermostat is just a piece of metal spring which change a size according to temperature.
Once it is in your car and running, Your water temp is affecting it all the time.
There is no way that it will hold the same temp all the time.
I can bet that most of guys that changed their thermostats about a year ago and was having 90 deg then, have about 85 deg now.
I cant also believe that Youre going to replace them every year to keep temp at 90 deg.
85 deg is perfectly fine as long as it keeps above 80deg.
Your Diesel Particle Filter need 75 deg to operate correctly, and your fuel consumption is not going to change when operating temp is just 5 deg lower!!

I was driving a nearly Brand New 530d loaner 2009 with 1500 miles on a clock and the running temp was 85 deg all the time, and never get higher.
So Youre not gonna tell me that it was broken already in a new car with 1500 miles on a clock , are You??

Reassuming:
If Your car gets 60-70 deg it is definately time to replace both termostats
If it gets more than 80 but slowly - I would go for EGR Thermostat and do nothing else. It will hold the same, maybe a bit more and get warm a lot quicker.
If You have 90 deg and after 6 months it dropped to 87 dont worry, its normal,

Thermostat is not an Ellectronic Part that can be adjusted, it is just a bit of metal
Trust me I am a metal Engineer and work with loads of that crappy metal stuff

So stop worrying too much and start Enjoying Your cars Guys!!
Life is too short...

mrbarry

A thermostat isn't strictly 'just a bit of metal'. It isn't even simply bimetallic. Its a spring closing valve that is opened via the thermal expansion of the media inside its core, a basic wax. Think of the mercury in a thermometer, as it heats it gets bigger.
As the operation of a thermostat in a car is analogue it can control the temperature very closely to its set point regardless of road/air speed and ambient temperature although they WILL effect it a small amount, as will driving style and air fuel ratios of the engines burn. A thermostats ability to control temps varies due to its operation being comparable to a proportional integral amplifier, only mechanical, for it to correct an error it must detect an error, if it fixes the error fully it will have no point of reference to operate and shut down. Typical uncorrected error for a thermostat is 2 or 3% So 2 or 3 degrees if you like.
As they age the operation temps will change a little, up or down! When to change for a new one, I would agree 80/82 ish.
As for fuelling altering with temps you can only know what at what temprature the ecu starts to add fuel if you have access to the fuel table in ecus maps, you can alter these tables so temps don't alter fuelling as and when BMW dictate, my car doesn't alter fuelling until under 65 degrees now, but thats another matter and not recommended for most peoples needs.

E60Sim

Got both thermostats changed. The car was running at 83-86 C before, and it now runs stable at 90-92 C. The fuel consumption dropped by 15% on the same commute to/from work, after the change.

madein

Lucky you, I will need to come back to the dealer, will see what is going to happened.....

Jarlo

Can anyone explain, why coolant temperature starts to drop, if I'm driving on higher engine rpm? For example if I go to manual shifting mode and I'm driving on 3000 rpm constantly, then coolant temperature started to drop slowly from 90 to 85 (after 5 minutes drive). It sounds logical if there is higher rpm, then temp goes higher not lower....
My friend had the same case. Mine car is 525d, friend's 530xd

Vista

I'd guess because the water pump is circulating water through the radiator faster and the flow rate isn't being properly regulated by the thermostat. i.e. the correct ratio between the rad and engine recirculation circuits isn't being maintained at the right level for the ideal running temperature

madein

I had 60 miles motorway trip and the temperature was on 82 degrees maximum, any idea what else can I check?

thx