[Jules59]

Ive observed that thermostat failure does seem to be a recurrent problem with 6 pot diesels and is not a major issue to solve if you know its happening. But these cars do not have a temp gauge and so the problem can go unnoticed for some time with poor MPG and DPF problems being the result.
Would anyone recommend that the thermostats are changed as a matter of course if you are unable to measure coolant temp ?
What would be a sensible change period ?

I use my Android phone app to keep an eye on coolant temp but ofcourse other people do not have or want to be bothered with that ability.

[coopersim]

Maybe just an occasional check of the temperature through the hidden menu?

[oldbilly]

another point is how long it takes to warm up, when I first bought my 330d it took ages to warm up (warm air from heater) about 3 miles, after changing both stats I get warmish air after 1/2 mile and thats in this cooler weather.

[blutak]

Ive been logging the temperature of the coolant for the last 2 weeks and no matter what driving style and current climate my temps always level off around 78-80c Took this to BMW thinking in their genius they might actually look at it but no, got a phone call today saying theres not a problem with them!

Will ring them tomorrow again to question their EGR "testing" methods!!

for what its worth it seems easier to change them yourself!!!

[mistryn]

Originally Posted by blutak

Ive been logging the temperature of the coolant for the last 2 weeks and no matter what driving style and current climate my temps always level off around 78-80c Took this to BMW thinking in their genius they might actually look at it but no, got a phone call today saying theres not a problem with them!

Will ring them tomorrow again to question their EGR "testing" methods!!

for what its worth it seems easier to change them yourself!!!

I can just imagine whats happen there, car goes into the garage they let it idle...gets up to temperature as the car is stationary and no air beng forced into the rad...temp shows 88-91 degrees = Nothing wrong with the stat Sir, that will be £xxx for us to look into this.

what really should happen is they take the car on a test drive and monitor the temp when air is being forced through rad.

Going into hidden menu, take a mechanic out with you on test drive but this is more like annoy the dealer as you should not know about this hidden feature and how dare you tell us what is wrong with the car and should let us investigate, pay us the diagnostic fee to tell you what you already know (you can see I have had expereince with this )

[blutak]

Originally Posted by mistryn

I can just imagine whats happen there, car goes into the garage they let it idle...gets up to temperature as the car is stationary and no air beng forced into the rad...temp shows 88-91 degrees = Nothing wrong with the stat Sir, that will be £xxx for us to look into this.

what really should happen is they take the car on a test drive and monitor the temp when air is being forced through rad.

Going into hidden menu, take a mechanic out with you on test drive but this is more like annoy the dealer as you should not know about this hidden feature and how dare you tell us what is wrong with the car and should let us investigate, pay us the diagnostic fee to tell you what you already know (you can see I have had expereince with this )

I know im not the only one lol! Its absolutely absurd! Why do these moronic dealers test these valves stationary. I want to see the mechanics face tomorrow when i show them the graphs ive made lol

[coopersim]

How did you make this graph? *want face*

[blutak]

Haha, can you tell I'm an engineer.... Just using the torque app for android and a Bluetooth obd scanner. Then export the logs, import in excel and hey presto, instant BMW dealership ammo!!

[HighlandPete]

Originally Posted by blutak

Haha, can you tell I'm an engineer.... Just using the torque app for android and a Bluetooth obd scanner. Then export the logs, import in excel and hey presto, instant BMW dealership ammo!!

Posted a comment in the other thread, I just despair at how some garages perform such simple tasks.

I think one of the problems, the average mechanic doesn't grasp how the BMW coolant circuit flows, and are not aware the EGR thermostat can short circuit and by-pass the main thermostat.

With a flow of at least 3-litres a minute (from a simple gravity flow test) though a failed EGR 'stat, that's a lot of heat loss and equates to about 18kW from 0 - 90C from some quick calcs. Never mind a pumped circuit and the chilling of cold coolant from the low side of the radiator.

If they don't make a road test and get real time temperatures it means nothing, as a static workshop 'warm up' is not a test at all.

HighlandPete

[coopersim]

Originally Posted by blutak

Haha, can you tell I'm an engineer.... Just using the torque app for android and a Bluetooth obd scanner. Then export the logs, import in excel and hey presto, instant BMW dealership ammo!!

Damn you iPhone! Back to pencil and graph paper for me

[blutak]

Originally Posted by HighlandPete

Posted a comment in the other thread, I just despair at how some garages perform such simple tasks.

I think one of the problems, the average mechanic doesn't grasp how the BMW coolant circuit flows, and are not aware the EGR thermostat can short circuit and by-pass the main thermostat.

With a flow of at least 3-litres a minute (from a simple gravity flow test) though a failed EGR 'stat, that's a lot of heat loss and equates to about 18kW from 0 - 90C from some quick calcs. Never mind a pumped circuit and the chilling of cold coolant from the low side of the radiator.

If they don't make a road test and get real time temperatures it means nothing, as a static workshop 'warm up' is not a test at all.

HighlandPete

Thanks HighlandPete, I'm really new to the BMW game lol, and am spending many hours reading up! Thanks for your help. Hope I can convince them tomorrow...

[blutak]

Originally Posted by coopersim

Damn you iPhone! Back to pencil and graph paper for me

Haha there is something similar for iPhones but I'm pretty certain you have to but a WiFi obd reader which are dam expensive!

[philmots]

It would be nice if someone who knows what they're doing could post up a good DIY..

I found one on a PDF but it wasn't that clear.

[Dave_3]

Originally Posted by blutak

I know im not the only one lol! Its absolutely absurd! Why do these moronic dealers test these valves stationary. I want to see the mechanics face tomorrow when i show them the graphs ive made lol

Where did you get your reference curve? Did that come from your app? Has all the info I was looking for : max temperature, and also predicted dynamic time to reach that temp - though that must have some tolerance due to possible varying engine loads during that time? I'm presuming the app requires you actually road testing, and not static (as Pete also pointed out).

Looking into that app now.

Dave

[mistryn]

^^ if I am thinking of the same pdf file I followed that and that was really good bar a couple of things missing

[HighlandPete]

Originally Posted by Dave_3

....- though that must have some tolerance due to possible varying engine loads during that time? I'm presuming the app requires you actually road testing, and not static (as Pete also pointed out).

Dave

Warm up time will not be a constant, can never be, as you say "engine loads". Then there is the ambient temperature and cooling efficiency. There is quite a bit of natural heat loss in the normal by-pass system around the engine, (even with good thermostats) during warm up. Then there is the HVAC demand, made worse at low temperatures.

I know from my own 330d you can even have temperature drop back during a proper warm up cycle. Simply due to coming off load on a long overrun, as there is just not enough waste heat to spare.

HighlandPete

[HighlandPete]

Originally Posted by mistryn

^^ if I am thinking of the same pdf file I followed that and that was really good bar a couple of things missing

There is definitely a good DIY pdf on this forum, attached to one of the thermostat topics.

HighlandPete

[Dave_3]

Originally Posted by HighlandPete

Warm up time will not be a constant, can never be, as you say "engine loads". Then there is the ambient temperature and cooling efficiency. There is quite a bit of natural heat loss in the normal by-pass system around the engine, (even with good thermostats) during warm up. Then there is the HVAC demand, made worse at low temperatures.

I know from my own 330d you can even have temperature drop back during a proper warm up cycle. Simply due to coming off load on a long overrun, as there is just not enough waste heat to spare.

HighlandPete

That is why I was wondering where the reference curve comes in that graph. The incline of the graph up to the stable temperature is probably just a best guess (as we both suggested that varies - so it can't be linear as depicted). But intersted in the source of the graph and whether the stable temperature (Tmax) is a fixed value from the manufacturer's data.

My temperatures are very similar to the graph posted - but probably take a bit longer to get to that temperature. Will be interesting to see how you get along, blutak.

D.

[coopersim]

Changed both mine today and my temp is up to 91 now

[blutak]

Originally Posted by Dave_3

That is why I was wondering where the reference curve comes in that graph. The incline of the graph up to the stable temperature is probably just a best guess (as we both suggested that varies - so it can't be linear as depicted). But intersted in the source of the graph and whether the stable temperature (Tmax) is a fixed value from the manufacturer's data.

My temperatures are very similar to the graph posted - but probably take a bit longer to get to that temperature. Will be interesting to see how you get along, blutak.

D.

No you are correct Dave the ideal temps are just that, a good guess from what people have posted on various forums about running temps etc. I did however get my car back today and as you all probably guessed they didnt change the thermostat. The technician basically said whilst the data i gave them is great and very useful for fault finding they can't use it as evidence of a faulty thermostat.

The tech said he took the car for a test spin around town and it seemed to heat up. It seems that in order for the part to be replaced under warranty it needs to be faulty and since there is no error code produced from this mechanical part they won't replace it. I keep telling them its not that its broken its that its not operating as efficiently as it should be.
Think im just gonna change them myself...

Changed both mine today and my temp is up to 91 now

What guide did you use, think im gonna attempt mine soon. Oh and does anyone know what part numbers to order for a 2006 330d e92?

Thanks!

[coopersim]

Originally Posted by blutak

What guide did you use, think im gonna attempt mine soon. Oh and does anyone know what part numbers to order for a 2006 330d e92?

Thanks!

I used this one (attached below) which is written by a member on here (credit shane55 - thank you!)

From Real OEM, looks like yours will be the same as mine for a 325d (same block, so makes sense)

Main stat: 11517805811 - http://realoem.com/bmw/showparts.do?...65&hg=11&fg=35
EGR stat: 11717787870 - http://realoem.com/bmw/showparts.do?...97&hg=11&fg=50

Don't forget to order this: 11532248435 (O-Ring for EGR stat) and a bottle of BMW coolant at the same time.