[docwalker]

Hi all

Hope you can advise me, over the past while I have found the fuel economy of 330d dropping pretty substantially.

So after doing some research I decided to check the coolant temperature and low and behold I found it was running low 70's and and briefly getting up to 77 at a maximum.

So I felt the EGR stat was probably at fault, so I changed this for a new BMW part and did the air filter at the same time. However during the change I lost a fair amount of coolant for some reason, so I tried to bleed the system via the EGR stat screw, I have now checked the car and on 2 occasions the temperature hasn't improved i.e still sitting around 71-74.

Any thoughts, could the main stat be at fault or have I not bleed the system enough?

Cheers

Steve

[mistryn]

Most likely the main stat will be the issue and need changing. If the the egr stat has gone generally the main stat is not far behind. it is a bit of a pain to change but do'able

[foxy-stoat]

+1 ^^^

I had the same temps on my 320d and changed both stats and now its solid 90 degrees after a short run.

Get the main stat changed asap.

[docwalker]

cheers guys, makes sense wasn't sure if I should expect an increase in to the 80's by the changing the egr alone.

I might book it in to get the main changed, on the plus side the car feels a load better with the air filter changed which isn't surprising I guess as it probably has been changed since new and now at 80k

[foxy-stoat]

If you still have your old egr stat, blow thru it, if you can then its donald duck'd. Ask the garage to give you the old stat, just so you can test it yourself.

If both stats are gone, then changing one and not the other probably wont do anything.

[docwalker]

hi there

I checked the old one and yes I could blow through it, was just surprised that it made no apparent improvement, but as you say if the main stat is gone that is fairly unlikely.

Cheers for the help, looking forward to getting the mpg back up again!!

[oldbilly]

I change both thermostats on mine,its not worth doing just the one!

[ade146]

Main stat and FWIW the euro car parts main stats are not OEM so use with extreme caution. I had to do mine twice. I really should know better by now.

[docwalker]

cheers guys

Used the dealers for the egr stat and will do so for the main stat, the prices aren't much different to eurocarparts anyway.

Will get the main stat replaced and report bad.

[K1 cgt]

Any progress on this, fear my 330d needs the same, egr stat was knackered, temps on long runs sit about 80, mpg suffering of late

[mistryn]

Originally Posted by K1 cgt

Any progress on this, fear my 330d needs the same, egr stat was knackered, temps on long runs sit about 80, mpg suffering of late

Main stat will need replacing, as above it is DIY

[ljw350]

hi, looking to buy a 330d manual, what should the avarage MPG be and how do you check the engine temp as can't seem to see a gauge on the dash/clocks. thanks

[foxy-stoat]

1. add up the last 5 digits of the vin number
2. With the key out of the ignition press and hold trip reset button
3. insert key with the trip button still depressed
4. press trip reset button 18 times so you have 19th menu wait untill lockon appears and wait for code 00 to appear
5. press trip reset button so the answer to step 1 appears next to the number 19
6. you should go back to 1st menu. press trip reset button 6 times to 7th menu
7. start the car up and you should get "ktmp-mom" and the temp will be displayed

Dont know about the real world mpg of a 330d

[mistryn]

If you fancy having a DIY bash, see Shane's excellent guide here
http://www.e90post.com/forums/showthread.php?t=632656

[ade146]

Real world mpg of mine roughly 15% sheer lunacy 15% town and 70% open roads with light foot is 39mpg. Thats over last 4 months since reset. Last time I reset before a 75mph motorway run I got around 42.5. I have modified it since and it is slightly better. They are ok but nothing fantastic. As so many threads have said before on diesel vs petrol I think its more of a case buy the engine you like.
On another note it is possible to fit an additional thermostat in the top hose. Im not saying you should but it is possible making it easy to change next time.

[E92Dan]

I get 43mpg out of mine.

[HighlandPete]

Originally Posted by ade146

...On another note it is possible to fit an additional thermostat in the top hose. Im not saying you should but it is possible making it easy to change next time.

I know what you are suggesting, but just be cautious, as there is not the same flow and preheat to the wax element, for an in-line top hose thermostat, as the OEM placement. The cooling system is not so reactive when instant cooling is required. Plus the OEM unit is not just opening to radiator at high temperature, it is controlling the by-pass and open internal coolant circuit. A faulty main thermostat left alone will be running too much coolant during warm up, even if you have a thermostat in the top hose.

The Rover guys with the BMW M47R engine are doing what you suggest in the Rover 75 cars. They have had to play with thermostat type and the bleed hole size, or the coolant system temperature is fluctuating all over the place.

OEM thermostat position is best placed for cooling in all circumstances.

HighlandPete

[ade146]

Sure it doesnt affect the egr bypass but water cant flow into the rad. Works well on mine. Cant remember the pilot hole size but whenever I check my temp its 86 to 90. I have not data logged it but it looks ok to me. I have changed both stats which didnt cure it so I added my own. I appreciate that it isnt the way to go but its worked well so far. I will one day get around to fitting yet another main stat.

[HighlandPete]

Originally Posted by ade146

Sure it doesnt affect the egr bypass but water cant flow into the rad. Works well on mine. Cant remember the pilot hole size but whenever I check my temp its 86 to 90. I have not data logged it but it looks ok to me. I have changed both stats which didnt cure it so I added my own. I appreciate that it isnt the way to go but its worked well so far. I will one day get around to fitting yet another main stat.

You mean you changed both ERG and main 'stat and it didn't get the temperature up to normal?

Are you driving an auto? Could be the gearbox oil cooler 'stat has failed, that would be helped by a top hose thermostat, as it stops the short circuit of coolant caused by a failed gearbox cooler 'stat.

HighlandPete

[Mr Singh]

I checked temperature today.

55°C on start
60°C after 60 secs of driving
70°C after 3 mins or so
85°C after opening her up down the bypass
95°C once I got back to where I started and let it idle for 60 secs.

I'm gutted, I wanted it to be broke so I could pick up my my 3-4 mpg from changing the stats

[shane55]

Originally Posted by HighlandPete

You mean you changed both ERG and main 'stat and it didn't get the temperature up to normal?

Are you driving an auto? Could be the gearbox oil cooler 'stat has failed, that would be helped by a top hose thermostat, as it stops the short circuit of coolant caused by a failed gearbox cooler 'stat.

HighlandPete

There's a gearbox cooling stat ;-) ?? Oh no, another Saturday with grazed knuckles coming up for someone!

[HighlandPete]

Originally Posted by shane55

There's a gearbox cooling stat ;-) ?? Oh no, another Saturday with grazed knuckles coming up for someone!

Problem is it is integral with the oil cooler itself, so not a cheap part. Same for E60/1 cars, needs a full replacement.

HighlandPete