Best way to drive a car with a failing thermostat

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Wed 14 Dec 2011 19:19
Best way to drive a car with a failing thermostat - jimmy_jazz

Hi this is going to sound like a weird question but

my bmw 330cd should run at 90 degs but the temp is only getting up to 65.

I share a lift with 3 people 70 miles and sods law it's my turn to drive this week. so I can't do it untill the weekend.

the question is if I drive in 5th it will go up to 70 degs. but if i put it into 6th it will go down to 60ish.but obvouisly the revs drop in 6th gear.

so what is the best way for best fuel ecomony?

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Wed 14 Dec 2011 19:57
Best way to drive a car with a failing thermostat - unthrottled

6th gear.

There might not be much wrong with the stat.

Diesel engines struggle to get up to full operating temperature when ambient tempereatures are low. The extra weight of will work the engine a little bit harder and raise the engine temperature slightly. Good excuse to drive at a higher speed ;)

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Wed 14 Dec 2011 19:59
Best way to drive a car with a failing thermostat - Collos25
I would suggest that you have other problems .
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Wed 14 Dec 2011 20:07
Best way to drive a car with a failing thermostat - jimmy_jazz

what would be the problem?

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Wed 14 Dec 2011 20:15
Best way to drive a car with a failing thermostat - oldroverboy

what would be the problem?

The problem can be safely cured! swap your driving period with whoever else you drive with and investigate the fault properly!

It's 330d what year what engine what mileage what age?

But first and foremost, investigate before changing bits, and if you do change bits, make sure you bleed the cooling system properly otherwise you will have other problems.

First port of call should be a BMW dealer or BMW specialist indie.

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Wed 14 Dec 2011 20:23
Best way to drive a car with a failing thermostat - jimmy_jazz

I've been dropping hints the last couple of weeks that i had this job to do on my car none of them took the hint.

it's a 2005 with 70k on the clock. 204 bhp.

I know the car has 2 thermostats I've already changed the easy one but it didn't cure the problem so I figured it was the water pump stat?

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Wed 14 Dec 2011 20:29
Best way to drive a car with a failing thermostat - unthrottled

Runninng the cr with a cool engime isn't going to do much harm-otherwise engines would never cope with winter cold starts, would they?

We all put off doing car maintainance in winter-it isn't fun after alL!

How long have you noticed the engine running cool?

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Wed 14 Dec 2011 20:36
Best way to drive a car with a failing thermostat - jimmy_jazz

only since monday

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Wed 14 Dec 2011 20:47
Best way to drive a car with a failing thermostat - unthrottled

Temperature has dropped this week. Big diesel engines loafing along in cool temperatures struggle to reach 90C.

I've known industrial engines struggle to achieve coolant temperatures of over 50C when left idling for extended periods in sub zero temperatures. Used to cause the dreaded phenonenom of bore glazing whereby partially burned diesel formed a varnish on the cylinder bores leaving a shiny surface which couldn't hold a film of oil.

Don't worry, this won't happen. Just get your foot down! If you want ultimate economy the 2.0d will be a better bet. Diesels like to work!

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