[ade146]

Yes it is an auto and yes both main plus egr stats changed a year ago. There was slight improvement as the egr stat was shot as usual. I didnt think of the auto box cooler but I can report I have had zero problems since my little mod. I even checked it on the way to work after talking about it here. I havent seen it do anything odd and I sometimes check live data with my launch. I will look into your suggestion, thanks.

[G_M_S]

OK - so thanks to all here, I pulled up the temp display hidden menu and took the car for a decent spirited run this morning, up and over the Dukes Pass - so can't imagine that it wasn't fully warmed up.

Normal driving - low 70oC, pushing it up hill 77oC max - stopped at the bottom of the run maximum recorded 81oC before dropping back to low 70's when driving.

Now my challange - does anybody know what BMW's spec is for the car and how would I go about claiming the replacement of the thermostats under my BMW Warranty?

Do BMW acknowledge the presence or validty of the hidden menu as a valid data source?

I've already got quotes from my local BMW dealer for replacement of both thermostats, prices include fitting and VAT, EGR Thermostat £53.88, Main Cooling System Thermostat £305.28 - which I don't think are bad, but given that the parts are probably faulty and I've paid for the warranty I would like to get them done and paid for by BMW.

Thoughts / advice please

[HighlandPete]

Originally Posted by G_M_S

Now my challange - does anybody know what BMW's spec is for the car and how would I go about claiming the replacement of the thermostats under my BMW Warranty?

Do BMW acknowledge the presence or validty of the hidden menu as a valid data source?

I did try and get data on this subject from my friendly BMW garage, but the workshop foreman and one of his techs couldn't find any definitive info for the diesel ECT in the BMW system. So we were none the wiser to whether BMW put a temperature level where a clear 'fault' is recognised in the thermostats, or in ECT fluctuation. The thermostats are temperature rated and there is a tolerance. Rover who used the same main thermostat element in the BMW M47R engine version have a rating and tolerance of 88C +/- 5C. The BMW main thermostat element is stamped 88C.

So I didn't pursue an extended warranty claim, just got on and did the job. There were no clear issues with my car, mpg hadn't dropped off, just knew it wasn't getting to the optimum ECT.

HighlandPete

[G_M_S]

HighlandPete,
Thanks as always...

Spoke to my dealer service manager, whom I get on quite well with and explained the temperatures I was getting, he spoke to their master technician and concurred that it sounded low. Agreed for them to get the parts, if they can find an error code or see that the unit is defective wen removed - they'll pursue a warrant claim on my behalf. If not it will be on my dime.

Economy has never been north of 37mpg and considering that when I had my previous 330i I was getting 32 mpg - I've always been suspicious something's not right.

Any way to physically tell if the parts are faulty? Heard references to the EGR valve being able to be blown through but what about the main thermostat?

Will report on outcome of the dealer visit Wednesday (never had issues getting appointments at short notice with these guys).

[mistryn]

Just a word of warning I remember reading a while back just before I replaced both my thermostats (highland pete will know as I asked a lot of questins and he was kvery helpfull)

I dont THINK it will show up a fault code - maybe dpf (if you have one) will show clogged/blocked and that can show a fault code resulting from engine temp not getting up operating temps to trigger a regen. However BMW may say you do short journeys.

However get them to test the temp when actually on a run, I have read another member who took his in as his was showing low 70's but BMW tech carried out the test while the car was stationary in the workshop - obviosly car still = no air = engine temp rising

for me the egr stat was £30 and the main stat was £44, took me 15 mins to do the egr stat and 4 hours for the main stat - reason why I wasnt too sure so was taking my time. But if I had to do it again I can get both changed in 2 hours to give you a rough idea of labour time

[HighlandPete]

Originally Posted by G_M_S

Any way to physically tell if the parts are faulty? Heard references to the EGR valve being able to be blown through but what about the main thermostat?

Will report on outcome of the dealer visit Wednesday (never had issues getting appointments at short notice with these guys).

You can easily blow through the EGR 'stat at room temperature if it has failed in the open position. Also the measurement at the element head is less.





BTW, as mistryn says, don't be fobbed off by workshop running temperatures. Any decent tech will know that static testing means nothing, for proving a thermostat opening temperature.

The only way to really prove a main themostat is running far too low, is to heat it up in water, with a thermometer to see the opening temperature.

Your signs are almost certainly a failed EGR 'stat, and possibly a low running main 'stat, but you can't prove the main 'stat unless you replace the EGR 'stat first and run again, or test the main 'stat in hot water.

Normal driving - low 70oC, pushing it up hill 77oC max - stopped at the bottom of the run maximum recorded 81oC before dropping back to low 70's when driving.

HighlandPete

[jimbo666]

I replaced both of my stats today. A very easy job. I was only hampered by the rain. Both stats and o-ring were £74.88 from BMW with discount. My car was struggling to get to 73deg. Now it reads a steady 90-95deg.

[G_M_S]

Had both thermostats replaced today by my BMW dealer, with the main stat being covered under my AUC warranty and I paid for the EGR stat - so £58 total outlay.

Exactly as per jimbo666, temp on the run down was 74deg and now its controlling around 93deg. Also as a plus, now getting an additional 5 mpg reported.

Originally Posted by jimbo666

I replaced both of my stats today. A very easy job. I was only hampered by the rain. Both stats and o-ring were £74.88 from BMW with discount. My car was struggling to get to 73deg. Now it reads a steady 90-95deg.

Thanks to all for advice and information.

[G_M_S]

Btw - didn't mind paying for the EGR valve because of course I get 2 years warranty on the part..

[Tony B]

I have a 2010 E91 330D M-Sport auto, which had to have a software update recently (intended to fix auto transmission adaptation problems) and since getting it back from the dealers it has covered nearly 400 miles but is struggling to get up to the previous fuel consumption.

I would say that it is now 10% worse than before. On the same round trips I used to get about 43mpg, sometimes as high as 46mpg and the end of the journey, but am now getting 39-40mpg.

I have checked the coolant temperature and it is currently not going above 87 deg C, even at a fast cruise for more than an hour. Unfortunately I did not check temperatures before the S/W update so have no basis for comparison.

Is 87 deg C hot enough? Current ambient temperatures are typically around 1-5 deg C where I have been using it.

And the S/W update has completely changed the transmission characteristics, with much less of a tendency to part throttle down-change, so I would have thought that this would help fuel consumption, rather than make it worse.

[HighlandPete]

Originally Posted by Tony B

I have a 2010 E91 330D M-Sport auto, which had to have a software update recently (intended to fix auto transmission adaptation problems) and since getting it back from the dealers it has covered nearly 400 miles but is struggling to get up to the previous fuel consumption.

I would say that it is now 10% worse than before. On the same round trips I used to get about 43mpg, sometimes as high as 46mpg and the end of the journey, but am now getting 39-40mpg.

I have checked the coolant temperature and it is currently not going above 87 deg C, even at a fast cruise for more than an hour. Unfortunately I did not check temperatures before the S/W update so have no basis for comparison.

Is 87 deg C hot enough? Current ambient temperatures are typically around 1-5 deg C where I have been using it.

And the S/W update has completely changed the transmission characteristics, with much less of a tendency to part throttle down-change, so I would have thought that this would help fuel consumption, rather than make it worse.

First point, if you are getting up to 87C without any strange fluctuations and it runs a steady 87C, it is not likely to affect the mpg or DPF regenerations. It is likely the main thermostat is tailing off a bit. Just keep an eye on it over the next few months and you will probably find it slowly decreases in the running ECT. Others, have run a while like you are finding, including my 330d. Mine took about a year to get down to low 80's, (without affecting the mpg), when I changed the main thermostat.

Second comment, your mpg. Don't panic until you prove the OBC is still running as before. My 330d was very accurate for the OBC to actual mpg. Then I had a software update for a couple of issues, but not for engine issues. Afterwards the OBC was not accurate anymore, reading ~10% under the real consumption. No idea why, but assume it changed some parameter which affected the OBC.

HighlandPete

[Somerset Jim]

Originally Posted by HighlandPete

First point, if you are getting up to 87C without any strange fluctuations and it runs a steady 87C, it is not likely to affect the mpg or DPF regenerations. It is likely the main thermostat is tailing off a bit. Just keep an eye on it over the next few months and you will probably find it slowly decreases in the running ECT. Others, have run a while like you are finding, including my 330d. Mine took about a year to get down to low 80's, (without affecting the mpg), when I changed the main thermostat.

Second comment, your mpg. Don't panic until you prove the OBC is still running as before. My 330d was very accurate for the OBC to actual mpg. Then I had a software update for a couple of issues, but not for engine issues. Afterwards the OBC was not accurate anymore, reading ~10% under the real consumption. No idea why, but assume it changed some parameter which affected the OBC.

HighlandPete

Sorry for diggin up an old post but it thought I'd ask since I've just changed the stats in my 330d. The temperature before was around 65-70 degrees and now it sits at 86 pretty much all of the time with the new stats. Should I be concerned that I have a duff set of stats and change them again or is this acceptable and won't create any long term problems?

[Buttons]

ok, here's a simple question that might get me shot down..........
how do you check the temperature?! lol

Ive noticed a significant drop in MPG lately (-4/5 MPG) and put it down to the weather!

[Precision Engineered]

Originally Posted by Buttons

ok, here's a simple question that might get me shot down..........
how do you check the temperature?! lol

Ive noticed a significant drop in MPG lately (-4/5 MPG) and put it down to the weather!

There's a hidden menu I think on the dash, also interested how you get into it.

[Somerset Jim]

Originally Posted by Buttons

ok, here's a simple question that might get me shot down..........
how do you check the temperature?! lol

Ive noticed a significant drop in MPG lately (-4/5 MPG) and put it down to the weather!

Try this...

http://e90.wikifoundry-mobile.com/m/...C+hidden+menus

[HighlandPete]

Originally Posted by Somerset Jim

Sorry for diggin up an old post but it thought I'd ask since I've just changed the stats in my 330d. The temperature before was around 65-70 degrees and now it sits at 86 pretty much all of the time with the new stats. Should I be concerned that I have a duff set of stats and change them again or is this acceptable and won't create any long term problems?

There has to be allowance for tolerances in the new thermostats and of course the ECT sensor. We don't have an exact temperature across every build, although typically we'd be reading around 90C, give or take a bit. We'd need to calibrate the ECT sensor to get a true baseline.

I ran my 330d for over a year at 84 - 86C, without any issues. The key thing to note is the engine warms to that temperature before the thermostat opens and regulates the ECT. In other words it goes straight up there in the warm up phase.

HighlandPete

[HighlandPete]

Originally Posted by Buttons

Ive noticed a significant drop in MPG lately (-4/5 MPG) and put it down to the weather!

Quite common to see a 10% (or more) drop in the winter season. Doesn't have to be a thermostat issue, but warm up will be a lot longer and electrical demands are much higher.

HighlandPete

[marklemac]

Originally Posted by HighlandPete

First point, if you are getting up to 87C without any strange fluctuations and it runs a steady 87C, it is not likely to affect the mpg or DPF regenerations.
HighlandPete

My 335d doesn't get up to high temps, usually low to mid 70's but I still get regular 'regens' every few days.

[HighlandPete]

Originally Posted by marklemac

My 335d doesn't get up to high temps, usually low to mid 70's but I still get regular 'regens' every few days.

75C is the figure we need to achieve for regenerations. Even if we do just get there, remember we are needing active regenerations as the means to get elevated EGT, rather than perhaps having some passive regenerations when running a hotter engine. Active regenerations also reduce mpg as we are forcing the temperature up with added fuel.

It is possible we are also having more regenerations at lower ECT, due to less efficient combustion and more particulate matter filling the DPF.

No real 'wins' for low ECT.

HighlandPete

[marklemac]

I notice in the BMWhat app, that is shows two different figures for the regen action. Sometimes it shows '3' and other times '6'.

'3' seems to be a very short regen, compared to 6 which takes longer.

[Somerset Jim]

Originally Posted by marklemac

My 335d doesn't get up to high temps, usually low to mid 70's but I still get regular 'regens' every few days.

How do you know when your car regens?

[marklemac]

Originally Posted by Somerset Jim

How do you know when your car regens?

I can literally feel it. Really hard to describe. (car feels lumpy through the throttle, hesitant).

I use the BMWhat App, and in the live monitoring you can see if the regen process is going in in there.