1.6HDi temperature / thermostat

[Robho]

Hi, 

What with this cold weather, I wonder if my engine is running at the correct temperature...

When fully warmed up, after say, 20 miles - the temperature gauge is showing a little over 70-degrees, whereas I believe the correct temperature is 83-degrees?

I replaced the temperature sensor as a cheap 'test'...in fact the new sensor reads as above (slightly lower than the previously-fitted one).

The thermostat doesn't look that straightforward  (unlike popping one in a saucepan of hot water to test it a few years ago!)..and isn't exactly cheap, and if all is correct I don't want to waste money on another.

I'd appreciate any feedback / tips from others' experiences 

many thanks.

[Gryffindor]

I don't have an answer, but before this coldish snap my 1.4 would get up to the very high 80s and stay there, but at the moment on very early morning runs (~4am), it struggles to reach 80 for the first 15 mins or so of running (maybe 7/8 rural miles?), and then rarely goes over 80. Also the cabin heater is not at all effective!

Every time I set off for work I wished I'd put a bit of cardboard in front of the rad (I only commute 10 miles so it wouldn't cause major issues for the cooling system), but every time I get home I forget all about it! So it must be running warm enough during the day for me not to notice anything.

[Robho]

I don't have an answer, but before this coldish snap my 1.4 would get up to the very high 80s and stay there, but at the moment on very early morning runs (~4am), it struggles to reach 80 for the first 15 mins or so of running (maybe 7/8 rural miles?), and then rarely goes over 80. Also the cabin heater is not at all effective!

Every time I set off for work I wished I'd put a bit of cardboard in front of the rad (I only commute 10 miles so it wouldn't cause major issues for the cooling system), but every time I get home I forget all about it! So it must be running warm enough during the day for me not to notice anything.

[Robho]

I don't have an answer, but before this coldish snap my 1.4 would get up to the very high 80s and stay there, but at the moment on very early morning runs (~4am), it struggles to reach 80 for the first 15 mins or so of running (maybe 7/8 rural miles?), and then rarely goes over 80. Also the cabin heater is not at all effective!

Every time I set off for work I wished I'd put a bit of cardboard in front of the rad (I only commute 10 miles so it wouldn't cause major issues for the cooling system), but every time I get home I forget all about it! So it must be running warm enough during the day for me not to notice anything.

Yes, that's similar to my experience currently (ie early morning, cold for 10-15 mins, heater indifferent till really warm, but mine's not getting as warm as your 'high 80s' on  a longer run

[Gryffindor]

Took it for a good drive today - 60 mile round trip on the M25 and A12. It got up to about 84 and the cabin was warm, but that was it.

[Sol]

My B9 as usual, this morning was cold (at -2 outside temp) till the first 3 miles then gets to 70 then by 5 miles it's at 80, fully warmed up it sits at 90 and the internal heater is roasting hot. That's in the city centre at 30mph. On the motorway from cold it hits 90 pretty quickly (3 or 4 miles)

[Robho]

My B9 as usual, this morning was cold (at -2 outside temp) till the first 3 miles then gets to 70 then by 5 miles it's at 80, fully warmed up it sits at 90 and the internal heater is roasting hot. That's in the city centre at 30mph. On the motorway from cold it hits 90 pretty quickly (3 or 4 miles)

I'm guessing the newer model is more efficient at warming up, that sounds much more like it!

I thought I'd try a small experiment this morning:

Once warm (well about 70-deg on the gauge), I sat with the car at a fast idle for a while. It reached the higher end of the 70s, that's all.

Now, the replacement temperature sensor, or the gauge I suppose, might not be that accurate of course. 

Also, it seemed like the temperature came back down to the mid-70s towards the end of my test - as though the cooling fan had cut in (though I wasnt able to check it this time.)

Thus, I think I can try:

- to test the thermostat...if anyone can tell me if this is feasible
- investigate if the fan is cutting in early ...if anyone can help with the temperature it should operate, and any tips on how to test it pls?

Cheers.

[Sol]

Ah if I park up, the HDi like all modern diesels, makes very little waste heat when not working hard and will drop back to 70 and stay there. It will not hold over 70 when idling. They're so thermally efficient.

A thermostat still tests in the normal way, drop it in a pan and heat the water on the cooker with a thermometer and watch the temperature it opens at. Usually 85.

[Sol]

If your internal heater is poor, the matrix may be crusted up inside or the controls are not sending fully hot water to the inside rad (matrix). 70 degrees is still far hotter than a human can stand, so once warmed through, even parked, the interior hot air on full setting is roasting hot even if the gauge is dropped back to 70.

At this point all of the metalwork should be at the same temperature so the heat is transferred to the blower air. You may have other issues not related to the engine temperature. Or the thermostat could be missing or stuck open. The probe for the gauge has no part in the heating temperature.

[jj9]

In cold weather my car takes a long time to warm up, after about 7 miles (15 minutes) of general driving the gauge is just hitting the 80° mark, the thermostat opens when the gauge gets around the 90° mark then drops back slightly and runs somewhere around 85°ish.

The thermostat is built into the plastic housing so you would have to remove the whole housing to test it.

I don't think the radiator fan comes on until north of 95°.

 

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