Overheating 1.8 - Page 5

planenut · 9th December 2020, 16:05

As to the "double stat", is it really necessary to leave a "b!ank" in the position of the original one, or is it okay to leave it empty?

T-Cut · 9th December 2020, 21:40

Quote:

Originally Posted by planenut

As to the "double stat", is it really necessary to leave a "b!ank" in the position of the original one, or is it okay to leave it empty?

The 'blank' is actually there to seal the stat housing together. The outer ring/annulus of the normal thermostatic valve has the case sealing ring bonded around it, somewhat like an O-ring. Since a PRT system precludes the usual K-series thermostat, MGR decided the easiest way to seal the now empty housing is to just replace the outer ring/seal. The ring is sometimes referred to as a 'flow orifice' or similar technical terms. It's basically a mounted o-ring seal.

TC

planenut · 10th December 2020, 06:33

Quote:

Originally Posted by T-Cut

The 'blank' is actually there to seal the stat housing together. The outer ring/annulus of the normal thermostatic valve has the case sealing ring bonded around it, somewhat like an O-ring. Since a PRT system precludes the usual K-series thermostat, MGR decided the easiest way to seal the now empty housing is to just replace the outer ring/seal. The ring is sometimes referred to as a 'flow orifice' or similar technical terms. It's basically a mounted o-ring seal.

TC

My apologies to e30325itourer for what may seem like a "hijack".

TC - so as the "o-ring" is not structural, it could be ommitted totally?

T-Cut · 10th December 2020, 10:55

Quote:

Originally Posted by planenut

TC - so as the "o-ring" is not structural, it could be ommitted totally?

EDIT: Looking at the Rimmer drawings, the rubber seal around the disc is supplemented by a separate seal. Even in the version for a PRT system, both seals are used, so I'm not sure it would work without using the orifice plate as well.

See: https://rimmerbros.com/Item--i-GRID001696

TC

e30325itourer · 15th December 2020, 15:07

Hi folks sorry it took me a while to get back to this, I have now removed the prt and pouring boiling hot water into the end with 1 opening it does not open but if I pour it in the end with 2 openings it let's water flow but very slowly, is this working properly? Also when shaking it there appears to be something loose inside.

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SD1too · 15th December 2020, 16:07

Quote:

Originally Posted by e30325itourer

... I have now removed the prt and pouring boiling hot water into the end with 1 opening it does not open but if I pour it in the end with 2 openings it let's water flow but very slowly, is this working properly?

I'm afraid Thomas that you'll need to be more scientific than that!

The usual testing method is to place the thermostat in a pan of cold water with a thermometer as close to the wax capsule as you can get. Now slowly heat the water and watch the thermostat closely. Note the temperature at which it begins to open and again when it is fully open. Now turn off the heat source and allow the water to cool, ensuring that the thermostat closes at the rated temperature as well.

Simon

COLVERT · 15th December 2020, 16:43

Quote:

Originally Posted by e30325itourer

Hi folks sorry it took me a while to get back to this, I have now removed the prt and pouring boiling hot water into the end with 1 opening it does not open but if I pour it in the end with 2 openings it let's water flow but very slowly, is this working properly? Also when shaking it there appears to be something loose inside.

Sent from my POT-LX1 using Tapatalk

Merci, monsieur T-Cut.

T-Cut · 15th December 2020, 21:25

Refering to the above drawing, the green valve is the one you test in hot water. The other is not involved. The wax capsule (brown) is what opens the green valve when the temperature is right. Pouring hot water in from the right hand port won't heat the capsule, so little if anything will happen. If you filled the left side chamber with hot water, by holding the stat upright(turned 90 degrees clockwise), then the capsule would be heated and may get hot enough to open the valve. The water would drain out as the valve cracked open.

EDIT: Some leakage past the green valve may occur because it has a jiggle valve to bleed air out. This is probably what rattles when a PRT is shaken.

TC

e30325itourer · 21st December 2020, 14:56

Checks done as recommended Simon the prt opens at 90 and closes fully at 64, does this sound ok?

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SD1too · 21st December 2020, 15:58

Quote:

Originally Posted by e30325itourer

Checks done as recommended Simon the prt opens at 90 and closes fully at 64, does this sound ok?

Thanks Thomas. The opening temperature is good but I'm a bit surprised that it's so slow to close. However, what's needed now is a test drive with the digital temperature display activated in the instrument pack.

Please report back!

Simon

15th December 2020, 15:07	#45
e30325itourer Loves to post mgztt190/bmw e30 325i tourer Join Date: Sep 2015 Location: Ballyclare Posts: 316 Thanks: 50 Thanked 50 Times in 41 Posts	Hi folks sorry it took me a while to get back to this, I have now removed the prt and pouring boiling hot water into the end with 1 opening it does not open but if I pour it in the end with 2 openings it let's water flow but very slowly, is this working properly? Also when shaking it there appears to be something loose inside. Sent from my POT-LX1 using Tapatalk __________________ My MGZTT This vehicle was the 2,432nd ZT-T to run off the production line, out of 8,249 This vehicle was the 847th ZT-T 190 + to be made out of 1,756 This vehicle was the 100th ZT-T in Starlight Silver (code: MBB) to be made out of 1,134 Starlight Silver ZT-Ts Last edited by e30325itourer; 15th December 2020 at 16:06..

15th December 2020, 21:25	#48
T-Cut This is my second home Rover75 and Mreg Corsa. Join Date: Nov 2006 Location: Sumweer onat mote o'dust (Sagin) Posts: 21,752 Thanks: 341 Thanked 3,660 Times in 2,924 Posts	Refering to the above drawing, the green valve is the one you test in hot water. The other is not involved. The wax capsule (brown) is what opens the green valve when the temperature is right. Pouring hot water in from the right hand port won't heat the capsule, so little if anything will happen. If you filled the left side chamber with hot water, by holding the stat upright(turned 90 degrees clockwise), then the capsule would be heated and may get hot enough to open the valve. The water would drain out as the valve cracked open. EDIT: Some leakage past the green valve may occur because it has a jiggle valve to bleed air out. This is probably what rattles when a PRT is shaken. TC Last edited by T-Cut; 15th December 2020 at 21:32..

21st December 2020, 14:56	#49
e30325itourer Loves to post mgztt190/bmw e30 325i tourer Join Date: Sep 2015 Location: Ballyclare Posts: 316 Thanks: 50 Thanked 50 Times in 41 Posts	Checks done as recommended Simon the prt opens at 90 and closes fully at 64, does this sound ok? Sent from my POT-LX1 using Tapatalk __________________ My MGZTT This vehicle was the 2,432nd ZT-T to run off the production line, out of 8,249 This vehicle was the 847th ZT-T 190 + to be made out of 1,756 This vehicle was the 100th ZT-T in Starlight Silver (code: MBB) to be made out of 1,134 Starlight Silver ZT-Ts

9th December 2020, 16:05	#41
planenut Regional Secretary Rover 1.8T Tourer Join Date: May 2007 Location: Heathrow Posts: 6,948 Thanks: 1,551 Thanked 2,036 Times in 1,264 Posts	As to the "double stat", is it really necessary to leave a "b!ank" in the position of the original one, or is it okay to leave it empty?