The Function and Malfunction of the Diesel Thermostat - Page 13

Jules · 24th February 2013, 15:37

I think the failure after typically 4 years is simply down to a poor quality spring material.

I suspect these stats are opening early in BMW's and Freelander TD4's but the owners may not be aware of it!

Don't forget folks if you are comparing warm up times typically between 5-7 miles, the other factor in the equation is the EGR jacket.
Some M47's were fitted with them and some weren't.
Obviously the water jacket type are going to warm the water system quicker by use of the hot exhaust gases.

Originally I thought these jackets were only fitted to later models with the air temp sensor in the intercooler hose with the 340 ECM's, but discovered the spec seems to be totally random.
ie Very early lower specced cars have them fitted

Mike Noc · 24th February 2013, 15:52

Thought they were only fitted to Autos Jules?

Mike

T-Cut · 24th February 2013, 16:16

Quote:

Originally Posted by Jules

I think the failure after typically 4 years is simply down to a poor quality spring material.

Personally, I can't see coolant at any temperature or age altering the spring temper. The spring provides effective closure (low hysteresis) on cool down. You've noted all failed stats are shut. IMO, it's more likely down to an internal malfunction of the capsule/piston system as described in the referenced patent. So what I suspect is a design factor rather than substandard materials. If that's the case, we'll eventually be reading about failures in replacement OEM stats. I seem to remember there's already one or two on record, but finding them will be tedious. It's an intriguing debate.

TC

Jules · 24th February 2013, 16:22

Quote:

Originally Posted by Mike Noc

Thought they were only fitted to Autos Jules?

Mike

Nope!
Seen many fitted to Manuals.....
Including our very own ZT

HarryM1BYT · 24th February 2013, 16:39

Just to add my 2 penarth...

I spotted the mentions of stat problems some 2.5 years ago and on checking mine found it holding the engine at 82C during the late summer, so got Andy to swap it. The warm up to 82C seemed to be quite normal, with the stat seeming to suddenly open judged by feel the top hose. After swapping it, it holds around the 88C mark. I have never heard the fan cut in even under maximum load and even in the summer, except for the a/c.

FrenchMike · 24th February 2013, 16:46

I guess lot of BMW cars are fitted with the same item,

BMW Ther.jpg

So i wonder if they encounter the same defective rate ?

Mike

NigelOBB · 24th February 2013, 16:49

It would be worth throwing it open to a BMW forum to see

HarryM1BYT · 24th February 2013, 17:05

Quote:

Originally Posted by NigelOBB

It would be worth throwing it open to a BMW forum to see

Good idea - any volunteers?

T-Cut · 24th February 2013, 17:31

I suspect I know what they'll say: http://en.wikipedia.org/wiki/BMW_M47

TC

MrDoodles · 24th February 2013, 17:38

I do seem to remember that there was a re-call when I was at BMW on the 1.9i 8 valve unit that was fitted into E46 316i and 318i and 318Ci models for exactly the same problem (thermostat sticking open) and if you read anything on the M47 engine BMW have exactly the same problem as well!

So must be that they have a poor supplier of thermostats, but you would think by now, that you could buy a thermostat for an M47 engine and that it lasted more than a year!

24th February 2013, 15:37	#121
Jules This is my second home ZT 260 SE Twilight and 10 other 75 ZT's :O Join Date: Jan 2007 Location: Conwy NORTH WALES Posts: 11,094 Thanks: 512 Thanked 1,116 Times in 763 Posts	I think the failure after typically 4 years is simply down to a poor quality spring material. I suspect these stats are opening early in BMW's and Freelander TD4's but the owners may not be aware of it! Don't forget folks if you are comparing warm up times typically between 5-7 miles, the other factor in the equation is the EGR jacket. Some M47's were fitted with them and some weren't. Obviously the water jacket type are going to warm the water system quicker by use of the hot exhaust gases. Originally I thought these jackets were only fitted to later models with the air temp sensor in the intercooler hose with the 340 ECM's, but discovered the spec seems to be totally random. ie Very early lower specced cars have them fitted __________________ [SIGPIC][/SIGPIC] Newbies do now!! 1. Plenum drains..all 3 or 4 year dependent 2. Cooling fan..All speeds functioning 3. Bonnet cable divider block

24th February 2013, 16:39	#125
HarryM1BYT This is my second home 75 Contemporary SE Mk II 2004 Man. Sal. CDTi 135ps, FBH on red diesel, WinCE6 DD Join Date: May 2010 Location: Leeds Posts: 17,273 Thanks: 2,160 Thanked 2,061 Times in 1,586 Posts	Just to add my 2 penarth... I spotted the mentions of stat problems some 2.5 years ago and on checking mine found it holding the engine at 82C during the late summer, so got Andy to swap it. The warm up to 82C seemed to be quite normal, with the stat seeming to suddenly open judged by feel the top hose. After swapping it, it holds around the 88C mark. I have never heard the fan cut in even under maximum load and even in the summer, except for the a/c. __________________ Harry How To's and items I offer for free, or just to cover the cost of my expenses... http://www.the75andztclub.co.uk/foru...40#post1764540 Fix a poor handbrake; DIY ABS diagnostic unit; Loan of the spanner needed to change the CDT belts; free OBD diagnostics +MAF; Correct Bosch MAF cheap; DVB-T install in an ex-hi-line system; DD install with a HK amp; FBH servicing. I've taken a vow of poverty. To annoy me, send money.

24th February 2013, 16:49	#127
NigelOBB This is my second home 04 Rover 75 Contemporary SE - 53 Rover 75 Connoisseur -94 Mercedes W140 - 72 VW Beetle 1300 Join Date: Sep 2012 Location: Sunderland Posts: 4,767 Thanks: 1,379 Thanked 493 Times in 429 Posts	It would be worth throwing it open to a BMW forum to see __________________ [SIGPIC][/SIGPIC] Keep smiling - it makes people wonder what you've been up to.

24th February 2013, 15:52	#122
Mike Noc This is my second home Rover 75 CDT Manual Connoisseur SE, Rover 75 CDT Automatic Connoisseur SE & a Freelander Td4. Join Date: Jul 2009 Location: Hampshire Posts: 11,550 Thanks: 3,470 Thanked 3,119 Times in 2,247 Posts	Thought they were only fitted to Autos Jules? Mike

24th February 2013, 16:46	#126
FrenchMike This is my second home Rover 75 Saloon Join Date: Aug 2007 Location: Avignon Posts: 4,466 Thanks: 94 Thanked 661 Times in 554 Posts	I guess lot of BMW cars are fitted with the same item, BMW Ther.jpg So i wonder if they encounter the same defective rate ? Mike

24th February 2013, 17:31	#129
T-Cut This is my second home Rover75 and Mreg Corsa. Join Date: Nov 2006 Location: Sumweer onat mote o'dust (Sagin) Posts: 21,753 Thanks: 341 Thanked 3,660 Times in 2,924 Posts	I suspect I know what they'll say: http://en.wikipedia.org/wiki/BMW_M47 TC

24th February 2013, 17:38	#130
MrDoodles Banned MG ZT+ V6 190 Join Date: Nov 2011 Location: Spalding Posts: 13,245 Thanks: 369 Thanked 1,196 Times in 818 Posts	I do seem to remember that there was a re-call when I was at BMW on the 1.9i 8 valve unit that was fitted into E46 316i and 318i and 318Ci models for exactly the same problem (thermostat sticking open) and if you read anything on the M47 engine BMW have exactly the same problem as well! So must be that they have a poor supplier of thermostats, but you would think by now, that you could buy a thermostat for an M47 engine and that it lasted more than a year!