Coolant temp never gets above blue zone

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Not normal. Mine gets up to temperature as fast as any car I've owned. Does the heater work well?

FWIW, there was a recall back in 2001 for the thermostat on my '99 328i.

Tom K.

hmm, it has a full BMW service history so am I correct in thinking that if there was a recall this would have been sorted?

sorry if I sound like a noob, its because I am! 5 months into my first!

One would think so, but I would have it checked out as the needle should be straight up after 3-4 miles or so. Of course, its easily possible that the thermostat was replaced and the new one is now stuck open after 5 years.

No problem. Hope you are enjoying your E39.

Tom K.

In the early nineties, on my E30, I got the thermostat stuck open causing rough revving on cold weather on the highway and bad ideling one or two minutes just after. When stopped for 5 minuyes or more, the temperature was almost correct. The dealer changed the four injectors and lotta more under warranty although I was claiming to look at the thermostat since, while driving fast, the needle was pointing towards 1/3 of the scale.

Exhausted of this waste of time and money, I decided to buy a thermostat and to change it. That ended all my problems until theu re-appeared last year after 180 000 km. I changed it again. BTW, if you replace it, make sure you mount it in the correct direction.

Teh dealer "Josh Assing" a écrit dans le message news: snipped-for-privacy@4ax.com...

yes, the heater works really well, positively tropical at 32 degrees (how do you get a degree symbol in Agent!?)

I've got a Haynes manual, I'll take a look and see if its something I can handle!

This is what a stuck open thermostat might look like in cold weather.

Dunno. 32°F? ;-)

If the heater works normally then the gauge must be reading incorrectly. So the engine temperature sensor would be my best bet.

ALT+0176

( 32° )

That's ALT+0176 on the Numeric Keypad, NOT the number keys on the top row of your keyboard ...

like others said; thermostat stuck open OR the sending unit bad. since you said the heater works well it is likely the sending unit is bad indicating the wrong temperature while it is fine. however, if it is the thermostat you are getting more wear on your engine than you want. It stays cold way too long. Thermostats are cheap, replace it I say. then if it's still not working, replace the sending unit.

A-HA! I've always wondered why this never worked for me (though I'm usually attempting the symbol for the British pound). I've only got laptops, so no dedicated keypads on any of my computers. Thanks for solving that little mystery. epbrown

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Kept a very close eye on it today to and from work:

To Work:

first ~8 miles town and country consistent 20-40mph top of blue area ~1/6 of dial

next ~10 miles motorway consistent 70mph middle of blue area ~1/12 of dial

next ~3 miles town stop/start traffic around first white line ~1/3 of dial

From Work:

first ~3 miles town consistent 20-30mph top of blue are ~1/6 of dial

next ~10 miles motorway consistent 70mph middle of blue area ~1/12 of dial

next ~3 miles town consistent 20-30mph top of blue are ~1/6 of dial

And the heater is NOT working, kept it on 32°C and fan on full blast on dash vents - at ~1/12 there was very little heat, at ~1/6 it was warmer and at ~1/3 it was warm but no where near as hot as I think it should be.

So I guess it must be a dodgy thermostat!

So next question is:

What do I need to buy? I've checked a few websites and phoned a few local parts places and there basically seem to be two options, some places only offer the first and other offer both:

2) Thermostat inner ~£15 Thermostat gasket ~£1.50 Thermostat housing ~£10

Now obviously buying separately is cheaper but do I actually need the housing? Most of places which drilled down to my specific model only feature the kit whereas some model specific sites list all 4.

My car is an E39 2000 V plate 528i - do I need the housing or just the thermostat & gasket?

Sorry for such a long post and thanks for all you help!

Generally just the thermostat and gasket. The housing (on mine) is plastic, but was ok when I changed my thermostat.

You'll also need the correct coolant to top up after changing it. A litre plus water should be fine. You'll also need to bleed the system properly - a google should easily find out details.

If the housing is made of aluminium, normammy, you shouldn't need to replace it. I'd rather buy a separate thermostat and the gaskets. Second, you'll probably need to dismount the fan. Usually a 32 mm nut reverse screwed. Just put a spanner on the nut, protect around (obviously) with al old piece of carpet and hit the spanner with a maller, the inertia will help you and the nut would easily release . But, check accurately the spanner dimension on your 528. You will need also to replace a large amount of cooling fluid.

"Shevek" a écrit dans le message news: snipped-for-privacy@4ax.com...

I haven't got a laptop that I can test the theory on, but laptops have a function key that when held (or pushed, or whatever it takes) will give you a numeric key pad. I would assume you would press the function key, then press and hold the ALT key and then press the keys on the numeric key pad that you get by pressing the function key first.

There is a Character Map (Start>Programs>Accessories>System Tools>Character Map) that will give you thousands of key strokes using the ALT Key + the numeric keys. Of course, you can copy and paste characters from the Character Map ...

That's what I do as I'd find it impossible to remember little used codes.