Temperature guage not going above ~30%

[Kalimsnor]

Hi!

So I've replaced my entire instrument cluster, as my car was originally USA-spec and I'm from Europe. I have have 325i cluster in my 325e. Sadly this also means my RPM is reading wrong (7k instead of 5k red line), but from what I've understood I need to fix my old SI board and put it in the new cluster. However the old SI board is soldered into oblivion by the previous owner, even a professional electrical shop said they wouldn't want to touch it.

Anyway, on to the "issue". My temp meter never really reads above 30%, even after driving for hours on end in temperatures up to 30 degrees celcius. It also creeps up to this 30% mark really slow. I'm assuming it's just a faulty gauge, and it shouldn't be a real issue. What I'm more worried about is if it ever were to run hot, I'm assuming it would get to 60-70% rather than 90-100%. Can someone clarify this?

[Kalimsnor]

Sneakily bumping this thread

[twright]

Are you sure that the the temperature is real and your thermostat isn't closing properly?

[Contours]

My temperature gauge never goes above 30% either and I have the car for years and done substantial mileage in that time. The car heats up quicker than my woman's modern Audi a3 . I would assume the gauge isn't faulty as this has been it's routine from the start. I could be wrong but I do not think the cluster has a bearing on the gauge reading.

[Kalimsnor]

Seems like the VISCO in my fan needs replacing. The fan turns on early on and is constantly cooling the engine, even when it shouldn't be. I think that's the issue.

Are you sure that the the temperature is real and your thermostat isn't closing properly?

I'm sure temp is good, but didn't test the thermostat.

[Kalimsnor]

So the viscous fan has been replaced and my temperaturemeter still won't go above ~30%

[Brianmoooore]

This was never going to be anything to do with the viscous fan coupling, but is likely to be everything to do with a duff thermostat, IF there is any problem at all.
Correct thermostat is 80 degrees, and that doesn't equate with the gauge needle being very far up the scale. Around the first white line is the correct position.

[Contours]

The viscous fan spins all of the time the engine is running. If it were faulty then your engine would heat up slightly while in traffic with a noticeable upward shift in your temperature gauge and resume back to normal when you're out on the open road. It may be the case that the car doesn't have the problem.

[BristolE30]

Sounds like your car is running perfectly, by the 30% I assume you mean the first white quarter mark on the temp gauge? Standard for a 325i, as it’s around 80c

[Blanca]

Just shift the needle, I did on my gauges for fuel, (reading too low, fill to half full and adjust) and temp (reading to low, get hot) so that under normal warmed up conditions they are at 12-o-clock. Also calibrated speedo using a GPS speedo on my mobile and a tacho on my timing light, they all needed a tweak.

[Brianmoooore]

Just shift the needle, I did on my gauges for fuel, (reading too low, fill to half full and adjust) and temp (reading to low, get hot) so that under normal warmed up conditions they are at 12-o-clock. Also calibrated speedo using a GPS speedo on my mobile and a tacho on my timing light, they all needed a tweak.

If the temp. gauge needle is near the first white line, where it should be, then moving the needle to make it read the middle white line will cause the needle to move into the red "stop the engine now" area when the temperature only rises a few degrees, as it is designed to when idling in traffic. Don't forget that the middle of the gauge is expanded and the end areas compressed.
It's a commonly held misunderstanding that the purpose of a speedometer in a car is to tell you at what you are driving. A speedometer is fitted to a car, by law, to enable the driver to be able not to exceed a speed limit in the area where they are driving.
If the reading on the speedo. is more or equal to the posted speed limit, then you are not in breach of the relevant law.
The speedo has to deal with tyres of varying tread depth, slip, and anything else affecting the rolling diameter of the tyres, and the fact that they are not ultra precision instruments, so all speedos are designed to over read at all speeds.
By all means check the calibration of your speedo, and make a mental note of it, but don't move the needle.
If you check your speed using the OBC display, you'll find it's much more accurate than the speedo.

[Blanca]

Just shift the needle, I did on my gauges for fuel, (reading too low, fill to half full and adjust) and temp (reading to low, get hot) so that under normal warmed up conditions they are at 12-o-clock. Also calibrated speedo using a GPS speedo on my mobile and a tacho on my timing light, they all needed a tweak.

If the temp. gauge needle is near the first white line, where it should be, then moving the needle to make it read the middle white line will cause the needle to move into the red "stop the engine now" area when the temperature only rises a few degrees, as it is designed to when idling in traffic. Don't forget that the middle of the gauge is expanded and the end areas compressed.
It's a commonly held misunderstanding that the purpose of a speedometer in a car is to tell you at what you are driving. A speedometer is fitted to a car, by law, to enable the driver to be able not to exceed a speed limit in the area where they are driving.
If the reading on the speedo. is more or equal to the posted speed limit, then you are not in breach of the relevant law.
The speedo has to deal with tyres of varying tread depth, slip, and anything else affecting the rolling diameter of the tyres, and the fact that they are not ultra precision instruments, so all speedos are designed to over read at all speeds.
By all means check the calibration of your speedo, and make a mental note of it, but don't move the needle.
If you check your speed using the OBC display, you'll find it's much more accurate than the speedo.

True, as far as the sprit of the law goes. Of course Spain has a different slant on things as usual.

What I meant was, If I am driving at 120Kph, normal working temp' and half a tank of gas then that is what my gauges show, not 'near enough' .

[Kalimsnor]

That is interesting, I always thought temp. gauges shold be around 50%. It is indeed at the first white line, so that means it's functioning as it should.

This was never going to be anything to do with the viscous fan coupling, but is likely to be everything to do with a duff thermostat, IF there is any problem at all.
Correct thermostat is 80 degrees, and that doesn't equate with the gauge needle being very far up the scale. Around the first white line is the correct position.

The thermostat and thermostathousing are both replaced a few months ago after my head gasket had blown.

[Brianmoooore]

Never make the mistake of assuming that a new part is either working properly or won't fail quickly. These things follow the well known 'bath tub' reliability curve.
Having said that, I still think there's probably nothing wrong. Posting a pic. of the gauge with the engine up to temp. would settle the issue.
Looking back at your OP, you mention SI boards. The rev. limit of your engine is determined by the engine ECU, and has nothing to do with red paint on the dial, and SI boards are interchangeable.

[Kalimsnor]

Never make the mistake of assuming that a new part is either working properly or won't fail quickly. These things follow the well known 'bath tub' reliability curve.
Having said that, I still think there's probably nothing wrong. Posting a pic. of the gauge with the engine up to temp. would settle the issue.
Looking back at your OP, you mention SI boards. The rev. limit of your engine is determined by the engine ECU, and has nothing to do with red paint on the dial, and SI boards are interchangeable.

Fair enough. The car is away for the winter, but I took it out for a quick spin to prevent it from staying put too long. Here's a bad-quality pic of the temp reading after driving for about 20 minutes and having it run idle for 10 minutes:

[Brianmoooore]

That's a little lower than it should be.
Was the gauge higher when driving? If it's been idling for a while, and the heater is on, then the heater may be putting out more heat than the engine's producing.
Did you change the 'stat yourself?

[Kalimsnor]

That's a little lower than it should be.
Was the gauge higher when driving? If it's been idling for a while, and the heater is on, then the heater may be putting out more heat than the engine's producing.
Did you change the 'stat yourself?

The gauge basically stays around this point. Temperature outside was about 2-5 degrees celcius, but it's roughly the same on warmer days. The heater was on indeed.

I will snap another picture when I take it out again to do some minor work on the fog lights. Might be a while, I'll bump this post when the time comes!

[Kalimsnor]

This is how high the temp goes after ~25 minutes of driving roughly 100km/h. Is there any way to check my engine temperature easily to see if the meter is (slightly) off?

[Brianmoooore]

It's slightly lower than I'd expect ,but only by a couple of degrees, so it's fine.
You can check with an infra red thermometer, or possibly measure the resistance of the blue sensor, and compare it with the published temp/resistance graphs for these sensors.

[Kalimsnor]

It's slightly lower than I'd expect ,but only by a couple of degrees, so it's fine.
You can check with an infra red thermometer, or possibly measure the resistance of the blue sensor, and compare it with the published temp/resistance graphs for these sensors.

OK great, then I'll leave it as is! Thanks

[Kalimsnor]

I purchased an infrared temperature reader to double-check, and the oil gets to roughly 90-95 degrees Celcius if I point it at the part where you can pour new oil into the block.