Official Operating temperature of an engine?

rG-tom

rG-tom

rG-tom

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Joined
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Hey,

I'm having some problems with BMW claiming that my thermostat is not faulty.

They are basically saying that because the ecu does not have a fault code, it is not faulty, despite the coolant temperature in the workshop menu not going above 65c even after hours of operation, sometimes as low as high 50s! When i first bought the car it sat around 90c all the time, 88-89 ish.

I have provided a photo of the workshop menu after an hour of driving etc but BMW service are saying that because I'm not supposed to access this menu they refuse to accept it as evidence, and are flat out saying there is nothing wrong with the car because the ecu has no faults.

326C73E6-7658-49F8-9192-F9BAA39B0365-2602-000002304A6C37DC_zps75fa51e1.jpg



At first he actually said it was the outside air temperature (59c in england at 11pm in february lol) until I provided him with the definitions below:


07.00 KTMP-MOM = Temp. Cooling Fluid (celcius)

07.01 ATMP-MOM = "Aussentemperatur" Temp. Outside (celcius)

I'm trying to find BMW's official stance on operating temperatures on the engine in the 335D so i can at least present this to them as well...anyone have any idea where to look? Once i have this I will be approaching the service manager instead of dealing with this service desk monkey.

any help would be appreciated.
 
That does seem very low. Arent most coolant gauges set between 75-100 (as the middle mark) meaning that normal temps should be between that range?

Does it still not go above 65 degrees even when revved for a bit and stationary?
 
it will go up if you force it like that but drop almost immediately, it wont sustain temperatures. As far as I am concerned and all bmw forums everyone is saying 90c, which rings true with my experience, but i need to find this officially.
 
You probably won't find it anywhere officially.

It's faulty though, you have 2 thermostats and one of them is broken. There is a main one and an EGR one.
 
[TW]Fox;23836529 said:
You probably won't find it anywhere officially.

It's faulty though, you have 2 thermostats and one of them is broken. There is a main one and an EGR one.
Click to expand...

Oh I know this, but trying to get BMW to accept this since "computer says no" is proving difficult.

This is extremely annoying as they had the car for four days to fix this and an issue with the glow plugs...they fixed the glow plugs but not this! I have a buyer for the car too waiting for this problem to be fixed :(

Tom.
 
The operating temp should be between 89-93 degrees. The DPF wont regenerate if its below 75 degrees and its at this point when the DPF blocks most people find out the stats are shot. The engine wont throw a fault code for failed stats and will just throw extra fuel in for cold runing temps, it doesn't work out how long the engine has been running against temp and just works the fueling out. Also be carefull with BMW diagnosing the car as they will watch the temp rise with it running in the workshop which has no airflow over the rad. You need them to watch the temps with the car being driven. They will cover the sats you just have to get the dealer onside.

If your anygood with a spanner you can do them yourself in a couple of hours easily.
 
Just had this reply:

I have checked with my warranty dept, we can look into this fault for you but it would not be covered on your warranty policy because there is
no diag code and no faults in the system, hence we are not prepared to take this any further.
Click to expand...

How would you play this fox?
 
Your thermostat is toast, the temp should get to around 90 or whatever the BMW spec is, within a few miles and stay near enough 90 degrees. I had a duff thermostat on my TT, and the temp would struggle to get to 75 cruising around. When ragging it around, it would get to 90, but then drop down to 75 again when your cruising it again.

Your fuel economy will be hurt by this, as the ecu will richen the mixture to get to the target temp, and oil temp won't be right. Just not good all round.
 
[TW]Fox;23836578 said:
Given where you live I would just go to another dealer, you have quite a few within 30 miles or so?
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It's getting the car to a dealer that is the problem, I am on borrowed time now and most seem very busy and cant fit me in for over a week :( This was the only dealer i could get to fit me in! I need this fixing this week if not before Thursday, I already lost last weekend due to them taking longer to fix the glow plugs than they said.


Will try speaking to their service manager first and then another dealer.
 
It's a real poor attempt at turning you away, saying "there's no fault code". Is there a fault code for a dodgy wheel bearing? A seized caliper? A knocking noise from the engine?
 
How much is the repair if you insist and pay?

I had a front drop link repaired under warranty (parts warranty as under 2 years old).

In the end I had to visit the dealer twice to get it rectified. In hindsight I should have bought the part for £25 and fitted it myself. It'd of been much less hassle.
 
The two stats and a litre of coolant comes to about £85. BMWs labour is about £170 per hour and the book time is about 1.5hrs. I did mine myself so BMW never knew for warranty purposes.
 
[TW]Fox;23837320 said:
How did you manage to tell which thermostat was faulty from his post?
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How did you come to the conclusion that i think the stat is faulty based on my post?

the OP asks about the operating temp of the engine. I have told him the opening temp of his termostat. is that not a good indication of the target coolant temp? what conditions would the water temp be out of that range?
 
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