[bayerischer]

hi, as soon as I was given a car there was something wrong and the car didn't had enough temperature, and my service changed the glow plugs and relay, and i saw a youtube video, that you have to remove coolant hose, so I suspect by removing this, it made thermostat to stuck, is this possible?

[Torqu3]

The thermostat was likely broken before there was any service done to it. It is a common problem on these cars.

[dmanb2b]

From a cold start you can also idle the engine with the coolant cap off to ensure there is no air in the system. You should have a steady stream of coolant flowing across the cap area.

As previously stated, you might have a bad thermostat, or two...I can't recall if the Euro models have two thermostats or one.

[Mark M]

Originally Posted by Torqu3

The thermostat was likely broken before there was any service done to it. It is a common problem on these cars.

Bingo. Thermostat failure seems to be a common issue on these engines. Catch is most times the threshold is not broad enough to cause a check engine light issue.

When the thermostat fails, the glow plugs and controller start working overtime to try and bring up engine temps. As a result the glow plugs and controller burn out.

Anyone replacing glow plugs should also replace thermostat.

[Diesel_Mike]

Is there a recommended mileage or age to replace the glow plugs and thermostats?

[dmanb2b]

Originally Posted by Diesel_Mike

Is there a recommended mileage or age to replace the glow plugs and thermostats?

Negative on glow plugs, no need to replace if good. My therm went bad after 5 years, best bet is to occasionally check coolant temp during long drive. If it is below 80 deg Celsius, it's failed.

[PhotoGuy87]

Originally Posted by Mark M

Bingo. Thermostat failure seems to be a common issue on these engines. Catch is most times the threshold is not broad enough to cause a check engine light issue.

When the thermostat fails, the glow plugs and controller start working overtime to try and bring up engine temps. As a result the glow plugs and controller burn out.

Anyone replacing glow plugs should also replace thermostat.

Is this only on BMW diesels? I've never heard of another diesel motor that uses the glow plugs to bring up the engine temps. My cousin who owns a shop that strictly only works on diesels said the same thing and that glow plugs are only used during starting the motor.

[TorqueAddict]

Originally Posted by PhotoGuy87

Is this only on BMW diesels? I've never heard of another diesel motor that uses the glow plugs to bring up the engine temps. My cousin who owns a shop that strictly only works on diesels said the same thing and that glow plugs are only used during starting the motor.

Here, refer to the following screenshots taken from BMW training manual:

[IMG][/IMG]






I have also attached the actual pdf, if someone wants to dig something else up.

[Torqu3]

Originally Posted by TorqueAddict

Here, refer to the following screenshots taken from BMW training manual:

[Pictures redacted to save space]


I have also attached the actual pdf, if someone wants to dig something else up.

Thank you so much for this! I had the same belief that glowplugs were only for cold starts, but it appears that mine have been running for 60 seconds every time I have started the engine since my engine always has time to cool down, it has been cold out, and my T-Stat is broken. Glad I have a new T-Stat and coolant coming in so I can get that squared away. And thanks for the PDF. Looks like I have something to read now.

[PhotoGuy87]

Originally Posted by TorqueAddict

Here, refer to the following screenshots taken from BMW training manual:

I have also attached the actual pdf, if someone wants to dig something else up.

Thank you for posting that! I learn something new everyday from this forum lol.