E91 330d Temperature Reduced

Somerset Jim · 12-02-2013, 07:02 PM

Hi folks,

I'm a newby here and have recently bought an E91 330d having had an E39 525d and an E46 320d previously but never had any need to seek advice previously!

The car I've just bought has 70k on the clock and seems to work fine in most departments apart from a broken voice recognition system and faulty bluetooth but I'll deal with these bits later.

The issue I have at the moment is that the engine seems to be running cooler than it should when on the open road (Motorways, A roads and B roads) at around 70 - 75 degrees centigrade. Once warmed up but in traffic for any length of time it'll get up to 88-90 degrees and stay at this untill the car is moving for a few minutes and it'll drop down to the previous mid to low 70's temps. This seems to be haing an adverse effect on the economy of the car as I'm averaging 29mpg with about 50% motorway driving and 20% town driving.

Can anyone here advise as to which thermostat this would suggest is broken and would it be a DIY replacement? I have experience tampering about with marine diesel common rail engines on my boats present and past but haven't tried much on cars.

All input would be greatly appreciated.

Digitalize · 12-02-2013, 07:11 PM

Based on dropping 20c, most likely the main stat, but change both. Been discussion on this, no need for another thread.

Somerset Jim · 12-02-2013, 07:31 PM

Ok thanks.

Are there any DIY's on replacing the main stat?

tmarshall57 · 12-04-2013, 03:55 PM

Quote:

Originally Posted by Somerset Jim

Ok thanks.

Are there any DIY's on replacing the main stat?

Yes - -here

http://www.e90post.com/forums/showth...ght=thermostat

Somerset Jim · 12-05-2013, 07:17 PM

Quote:

Originally Posted by tmarshall57

Yes - -here

http://www.e90post.com/forums/showth...ght=thermostat

Thanks.

Have changed the egr stat today since that's the easy one to do and will find out the results tomorrow... Fingers crossed there's an improvement.

Digitalize · 12-06-2013, 07:50 AM

I highly doubt just EGR will fix, may give you a few degrees.

Somerset Jim · 12-11-2013, 06:47 PM

All done and changed in about 2 hours this afternoon

Economy now improved by at least 10 mpg from a quick 20 mile test.

There was oil in the pipe leading to the turbo which has to be removed to replace the stat. Is this a regular occurrence or should I be worried? I have checked the oil level and all seems fine. This hasn't been altered since the last oil change just under a year ago.

I have taken a photo of the new versus old thermostat. I'll let you have a guess as to the old one!

12-02-2013, 07:02 PM	#1
Somerset Jim Captain 23 Rep 617 Posts Drives: E93 M3 LCI DCT & F01 730d SE Join Date: Nov 2013 Location: Wellington, Somerset iTrader: (5)	E91 330d Temperature Reduced Hi folks, I'm a newby here and have recently bought an E91 330d having had an E39 525d and an E46 320d previously but never had any need to seek advice previously! The car I've just bought has 70k on the clock and seems to work fine in most departments apart from a broken voice recognition system and faulty bluetooth but I'll deal with these bits later. The issue I have at the moment is that the engine seems to be running cooler than it should when on the open road (Motorways, A roads and B roads) at around 70 - 75 degrees centigrade. Once warmed up but in traffic for any length of time it'll get up to 88-90 degrees and stay at this untill the car is moving for a few minutes and it'll drop down to the previous mid to low 70's temps. This seems to be haing an adverse effect on the economy of the car as I'm averaging 29mpg with about 50% motorway driving and 20% town driving. Can anyone here advise as to which thermostat this would suggest is broken and would it be a DIY replacement? I have experience tampering about with marine diesel common rail engines on my boats present and past but haven't tried much on cars. All input would be greatly appreciated.
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12-02-2013, 07:11 PM	#2
Digitalize Photographer 407 Rep 2,635 Posts Drives: 320D Join Date: Jun 2013 Location: UK iTrader: (0)	Based on dropping 20c, most likely the main stat, but change both. Been discussion on this, no need for another thread.
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12-02-2013, 07:31 PM	#3
Somerset Jim Captain 23 Rep 617 Posts Drives: E93 M3 LCI DCT & F01 730d SE Join Date: Nov 2013 Location: Wellington, Somerset iTrader: (5)	Ok thanks. Are there any DIY's on replacing the main stat?
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12-06-2013, 07:50 AM	#6
Digitalize Photographer 407 Rep 2,635 Posts Drives: 320D Join Date: Jun 2013 Location: UK iTrader: (0)	I highly doubt just EGR will fix, may give you a few degrees.
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12-11-2013, 06:47 PM	#7
Somerset Jim Captain 23 Rep 617 Posts Drives: E93 M3 LCI DCT & F01 730d SE Join Date: Nov 2013 Location: Wellington, Somerset iTrader: (5)	All done and changed in about 2 hours this afternoon Economy now improved by at least 10 mpg from a quick 20 mile test. There was oil in the pipe leading to the turbo which has to be removed to replace the stat. Is this a regular occurrence or should I be worried? I have checked the oil level and all seems fine. This hasn't been altered since the last oil change just under a year ago. I have taken a photo of the new versus old thermostat. I'll let you have a guess as to the old one! Attached Images
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