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Thermostat Housing -ramblings

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gmerry   
Thu Dec 10 2015, 02:55PM
Joined: Dec 11 2009
Member No: #21
Location: Scotland
Hi all, I've attached a photo of a thermostat housing split open where the two 1/2s are glued together. A five pence coin can easily be inserted into the split flange. There's no sign of brittleness in the plastic: I'm assuming that the glue joint failed due to age, vibration and pressure. The actual failure happened with the engine revving to max, on the limiter and no it was not me with my pedal to the metal. Can't help but thinking this thermostat housing looks like a scorpion ... and can sting like one too!

Anyhow, I managed to pinch the seal when installing the new housing, working in poor light and rushing the job. Hunting for a new seal(s), I've discovered that LandRover stock replacement seals for the joints to the cylinder heads but Citroen don't whilst Citroen stock the O ring #198171 that seals the thermostat housing to the oil cooler, (but LR don't).

Anyhow, keep a vigilant eye out for failures of this component.

Regards
G



3 User said Thank You to gmerry for this Post :
 321dave (10 Dec : 18:26) , cruiserphil (13 Dec : 10:34) , e3steve (14 Dec : 06:53)
cruiserphil   
Sun Dec 13 2015, 10:35AM

Joined: Jan 24 2010
Member No: #38
Location: Celbridge
G,

Was it at MOT? That's were our last tank episode occurred!

Best regards,

Phil C.
1 User said Thank You to cruiserphil for this Post :
 gmerry (13 Dec : 12:07)
gmerry   
Sun Dec 13 2015, 12:10PM
Joined: Dec 11 2009
Member No: #21
Location: Scotland
YES!!!

Completely pointless test for a modern common rail diesel with Particle Filter!

Anyone know how to modify the limiter (maximium revs) in the SID201 ECU?

Regards
G
1 User said Thank You to gmerry for this Post :
 cruiserphil (13 Dec : 21:52)
e3steve   
Mon Dec 14 2015, 07:27AM
Joined: Jan 21 2013
Member No: #1163
Location: Warsash, Hants & Palma de Mallorca, Spain
It's a barstered when it does that. Nothing you can do; not even limp home. It's a real Achilles heel within Ford's 'Lion' engine!

I'm off, back into deepest rural France on Boxing Day and I'm considering carrying a spare! It's been over two years and around 20k miles since mine puked.

I do have this theory, though: perhaps the use of a water-mixed coolant - as opposed to a 'pure' and non-mix - could be causing the issue. My tank split not long after I bought the car, and I have no way of knowing if POs had adhered to the rules of using a dedicated coolant. Water content in a closed cooling system will expand as the temperature rises, whereas a pure coolant (I now only use a recommended BASF Glysantin G30 from 'Comma') creates very little expansion, even if the 'stat was to fail shut. This phenomenon can be proved by removing the cap from the header tank when the engine is at its hottest. There's no dramatic attempt for the coolant to escape under the massive pressure that a water-mix does. Just the merest "fsssst" as the cap's seal is broken.

Just a theory...
1 User said Thank You to e3steve for this Post :
 cruiserphil (15 Dec : 08:04)
321dave   
Mon Dec 14 2015, 04:18PM
Joined: Sep 09 2011
Member No: #614
Location: Dublin
e3steve wrote ...

It's a barstered when it does that. Nothing you can do; not even limp home. It's a real Achilles heel within Ford's 'Lion' engine!

I'm off, back into deepest rural France on Boxing Day and I'm considering carrying a spare! It's been over two years and around 20k miles since mine puked.

I do have this theory, though: perhaps the use of a water-mixed coolant - as opposed to a 'pure' and non-mix - could be causing the issue. My tank split not long after I bought the car, and I have no way of knowing if POs had adhered to the rules of using a dedicated coolant. Water content in a closed cooling system will expand as the temperature rises, whereas a pure coolant (I now only use a recommended BASF Glysantin G30 from 'Comma') creates very little expansion, even if the 'stat was to fail shut. This phenomenon can be proved by removing the cap from the header tank when the engine is at its hottest. There's no dramatic attempt for the coolant to escape under the massive pressure that a water-mix does. Just the merest "fsssst" as the cap's seal is broken.

Just a theory...


Hi Steve, that's a very good point about the use of diluted concentrate versus ready mixed solutions. Is ready mix already mixed with de-ionised water or is it a pure chemical mix, if that makes sense!
gmerry   
Mon Dec 14 2015, 05:18PM
Joined: Dec 11 2009
Member No: #21
Location: Scotland
Hi Steve, same as you I have noticed a reduction in pressure... not sure of the reason because Comma readymix G30 is MEG/Water at about 50 to 60% v/v and vapour pressure of 60% MEG aqueous solution at say 90 degrees C is only fractionally lower than pure water. Another explanation is that the cooling system is running cooler????

Regards
G
e3steve   
Mon Dec 14 2015, 09:51PM
Joined: Jan 21 2013
Member No: #1163
Location: Warsash, Hants & Palma de Mallorca, Spain
According to BASF's recommendations we should be using Glysantin G33, but I've also seen written that G30 is more than acceptable.

G30 comprises just 3% water, has a much-elevated boiling point of >160°C and a freezing point, when mixed 50/50 with water, of below -38°C.

It's also, it seems, their recommendation to use it in a 50% mix... I use it undiluted!
3 User said Thank You to e3steve for this Post :
 gmerry (14 Dec : 23:11) , cruiserphil (15 Dec : 08:03) , 321dave (15 Dec : 12:02)
gmerry   
Mon Dec 14 2015, 11:15PM
Joined: Dec 11 2009
Member No: #21
Location: Scotland
Hi Steve, that is an interesting post.

G30 Readymix is 40-50% water. Are you using the G30 concentrate straight!

Note that G33 is only available in bulk for first fill PSA and Citroen/Peugeot rebranding (not available retail in the UK}. G30 is identical to G33 except for the dye colour.

Regards
G
3 User said Thank You to gmerry for this Post :
 cruiserphil (15 Dec : 08:04) , 321dave (15 Dec : 12:02) , e3steve (15 Dec : 15:49)
gmerry   
Tue Dec 15 2015, 08:24AM
Joined: Dec 11 2009
Member No: #21
Location: Scotland
Hi all, here's some further data on the perils in the use of ethylene glycol as an undiluted coolant. Basically, beyond 68% v/v, the freezing temperature INCREASES, the heat transfer potential reduces and the additives are likely to precipitate out of solution at operating temperatures.




3 User said Thank You to gmerry for this Post :
 Tjensen (15 Dec : 09:35) , 321dave (15 Dec : 12:02) , e3steve (15 Dec : 15:49)
e3steve   
Tue Dec 15 2015, 03:55PM
Joined: Jan 21 2013
Member No: #1163
Location: Warsash, Hants & Palma de Mallorca, Spain
Until I scanned BASF's website I was unaware that Comma Xtreme G30 was actually meant to be diluted! In previous engines I've used Toyota's 'Forlife' coolant, which is a straight, from-the-container non-mix.

I also use Volvo Penta's marine stuff in my other cars, but that's ready-mixed 40/60.
1 User said Thank You to e3steve for this Post :
 J_K (03 Nov : 05:44)
e3steve   
Tue Dec 15 2015, 04:05PM
Joined: Jan 21 2013
Member No: #1163
Location: Warsash, Hants & Palma de Mallorca, Spain
Boom!



Oops...
Dave-Retired   
Tue Dec 15 2015, 04:13PM

Joined: Oct 01 2009
Member No: #1
Location: Northumberland
If you want something to use straight from the can (well plastic container' I use this - Click Here - in the 2 classics...
Website
1 User said Thank You to Dave-Retired for this Post :
 e3steve (16 Dec : 05:42)
gmerry   
Tue Dec 15 2015, 05:36PM
Joined: Dec 11 2009
Member No: #21
Location: Scotland
My local "speedshop" sell G30 Readymix in a 5 litre container so this is probably the most user friendly package. Or they sell the concentrate for diluting with nice soft Scottish water - complete with tannins for corrosion protection.

Regards
G

PS, musing some more on the thermostat housing, the flanges are pretty well held together by the screws for access to the thermostat. The corner with the 5 pence coin probably just needs a crimped metal "hog ring" to hold it together and prevent a "peel" failure of the glueline.


c6kev   
Tue Dec 15 2015, 06:56PM
Joined: Dec 02 2013
Member No: #1508
Location: Wales
I don't think that it is the pressure rise with temperature that causes the problem with these housings. When mine failed, there was only the lightest mist of escaping coolant from idle speed to about 2000 rpm (ie almost all of the time). However, as the revs rose towards 3000, the extra flow from the water pump forced the housing apart turning the mist into a major spurt. I didn't try revving to the red line, but I can see how you could lose a lot of coolant very quickly during a kickdown overtaking manoeuvre - just when the engine really needs some cooling!

I don't remember the detail now, but a couple of tie wraps were used to prevent the joint opening too wide at higher revs for a couple of weeks while I waited for parts - why do these things always happen during the Xmas shutdown?

Can't wait to get my electrical gremlins fixed and get back into the 6. You don't remember how good these cars are until you have do without them for a week or two.

Kevin
speedfix   
Wed Dec 16 2015, 08:27PM
Joined: Sep 28 2012
Member No: #1043
Location: south west
[The actual failure happened with the engine revving to max, on the limiter.]

The Mot states that first a purge of the vehicle is carried out at half the max revs ie 2500 rpm.

Emission testing is carried out in under one and a half seconds on the limiter.


For this to happen IMO the thermosat housing pic shows a real cause of the problem.


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