| Author | Message | ||
     Gordon Norris Frequent User Username: crewes_missile Post Number: 64 Registered: 2-2005 |
In 2002, a new thermostat was introduced (PG 58252PA) that is backwards compatible to 20000 cars onwards. (Cars prior to 1987 must still use the old thermostat UE36600) The service bulletin simply states "the specification of the thermostat has been revised to ensure optimum coolant temperature" The new one no longer has the lead fusible links and is brass/plated and looks like most other "conventional" thermostats. I realise that running cold can be just as harmful, if not more-so, than overheating under some circumstances, but I always felt the fusible links were a good idea and offered a bit of extra protection from a stuck thermostat. I'd like to know peoples thoughts/preferences and does anyone know for sure the rationale for the change, why the insistance that pre-20000 cars must use the old, and finally why the heck the new one costs 50% more!! GN. | ||
| Gordon Norris Frequent User Username: crewes_missile Post Number: 68 Registered: 2-2005 |
Well, finished fixing my heater tap today, and some hoses and bits and pieces of cleaning along the way. While I've got the system drained I'll give it a flush and replace the thermostat. I have one of each type of thermostat on hand, and would like to hear peoples opinions about which they think would be best, so I can mull over it before I refill the system. I'm tending to lean toward the older type with the fusible links, but then again they upgraded for a reason, or was it just economic rationalisation, ..or, ..but, ..or...  GN. | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 631 Registered: 4-2003 |
Gordon, Hardly a matter for any loss of sleep, but I would use the older style one. 1. They work perfectly. 2. The fusible links work (Bill C. showed me one in January with the fusible links gone in service) 3.The older one needs to be used up anyhow 4. Let some other mug discover the merits or otherwise of the newer style. I put a new one, with fusible links, in my Turbo R at Christmas due to slightly cold running by the way. I have had it in the store room for two years, and was not aware of the newer type. VW economy ? RT. | ||
| Larry Halpert Prolific User Username: larry_halpert Post Number: 50 Registered: 9-2003 |
Maybe the newer one is off the shelf for other cars, so they don't have to keep custom making the one with the fusible links. Now to figure out what other cars the newer one is also for. Larry tbird@consultant.com | ||
| Gordon Norris Frequent User Username: crewes_missile Post Number: 69 Registered: 2-2005 |
Thanks Richard and Larry. I might go to my local "Supercheap" auto store where they have literally a wall of thermostats for different makes and see if the new one matches any recent VW/BMW/generic teutons. Isn't it a real cheek though that they charge 50% more for it! I thought it might be a "local" mark-up, but perusing my Introcar 2003/04 catalogue, it is similarly marked up in the UK. And as to why they say pre-20000 cars MUST use the old one is a mystery...was there a different by-pass arrangement on those cars? Will let everyone know if I find a more economical match for the new one... Cheers, GN. | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 633 Registered: 4-2003 |
Gordon, Do let us know if the later thermostat opens at a higher temperature by placing both in a saucepan of water and heating them up. My temperature gauge always runs rock steady less than 1/3 into the normal zone. That is at -20 and +40 ambients alike. That is normal for these cars it seems. At Christmas, it ran cooler for some minutes after a high speed bash, and the heater went cold. All fixed with a new thermostat, but maybe they run too cool with the original thermostat ??? On their site, Introcar only list the fusible-type thermostat at £24. I can live with that price. Maybe their printed catalogue lists both types, but the web site was updated very recently. Curious. RT. | ||
| Gordon Norris Frequent User Username: crewes_missile Post Number: 70 Registered: 2-2005 |
Yes Richard, it is a little curious. Both thermos have 88 stamped on the bottom of them, which is usually the opening temp in Celcius, but I'll do a side by side test in a saucepan tomorrow. How quickly they open may vary. The Introcar listing and prices in the catalogue are: Thermostat UE36600 Suit 1000-20000 GBP23.59 Thermostat PG58252PA Suit 20000-57000 GBP32.96 GN. | ||
| Gordon Norris Frequent User Username: crewes_missile Post Number: 71 Registered: 2-2005 |
Richard, my car does the same and my guess was that perhaps the old style thermostat made them run a bit cool as you surmised. However, curiosity got the better of me and I couldn't wait until tomorrow...here are the test results...NOT what we guessed: I tested the thermostat that was in the car (old style with lead), a brand new old style, and the new type without lead, numbered A,B,and C respectively. Tested simultaneously in the one saucepan using a digital thermoprobe. Results checked over 3 separate testing cycles in case new ones a bit "sticky". The results were consistent in all 3 cycles. A. Starts opening 89C Fully open 98C B. Starts opening 88C Fully open 97C C. Starts opening 88C FULLY OPEN 93C 1 & 2 show 1 degree variation, with the older one opening slightly later, but both with a 9 degree spread. The new style opens fully in only a 5 degree spread. It was really noticeable how the new style opened wider much more quickly..the old ones were only open just a crack after the first 2-3 degrees after starting to open, whereas the new style was well over half open at that point. Interesting... It would go some way to explaining the deletion of the lead links, in that the new one opens with greater vigour and may be less likely to stick, or if it starts to stick it may do so already opened wider...awww cripes...who am I kidding..it's probably just about economy..make it cheaper and sell it for more!! And by the way, it is stamped "Waxstat" "Made in England" and all dimensions are the same as the old style; just brass or brass plated rather than the silver-grey of the old style. GN. | ||
| Robert Wort Grand Master Username: robert_wort Post Number: 138 Registered: 12-2004 |
That's very interesting Gordon. I appreciate your tests. Will this mean that the new thermostats will make the heaters run even cooler at speed being that they open fully much quicker? | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 634 Registered: 4-2003 |
Gordon, Interesting indeed. Note that aftermarket thermostats in the UK are marked by their fully-open temperature, whilst in the US it's the temperature at which they start to open. Waxstat is a supplier to many OEMs. I would start with Jaguar XJ6. I assume you laid the thermostats on a plate or the like in the saucepan to avoid metal-to-metal conduction. I think I'll take my old thermostat to a parts store to see if I can find a compatible one for fun (size and temperature). I note that Waxstat thermostats usually sell for around A$15. Could you post a picture of the new one ? Here is the old type, courtesy of Introcar. RT.  | ||
| Gordon Norris Frequent User Username: crewes_missile Post Number: 72 Registered: 2-2005 |
Richard, Both my digital camera and scanner got zapped in a recent thunderstorm, (the camera while on charge), and I've been too slack to replace them as yet, but it looks the same but with no lead plugs and the different golden colour. Also relevant to the temperature markings, as I said it is stamped 88 on the underside, but also on the top rim is a tiny and much more faint 93 which I didn't notice before, corresponding to opening and fully open temps. And yes, the thermostats actually stood on a wire collander type thing immersed in the water so they didn't touch the bottom of the saucepan. And yes, Robert, the heater question is an interesting one. If I do decide to try the new one I'll let you know how the heater goes. Crewe seem to have a talent for confusing the issue sometimes... GN. | ||
| Bill Coburn Grand Master Username: bill_coburn Post Number: 357 Registered: 4-2003 |
Does anybody ever write to Crewe these days? 25 Years ago you would write to get a reply from Larry Yarwood who was most courteous and usally helpful although the essence of bovine detritus was in plentiful supply where loss of face was perceived. I once wrote and asked had they got a solution to the torque arms snapping their neck off on the early Shadows. Back came a reply that they had no knowledge of such events and here in Canberra was the Yorks Motros demonstrater stranded by Lake Burley Griffen with guess what!! All this to say has annybody written to Crewe to say why are you fiddling with the thermostats? | ||
| Gordon Norris Frequent User Username: crewes_missile Post Number: 73 Registered: 2-2005 |
Dear Bill, Once upon a (gentler) time, far, far away (in the mists of time) I would have done just that, and probably recieved a gentle, courteous, and helpful reply. But, I am led to believe, the factory isn't interested in owners of the non-VW cars, and we are but a nuisance that they hope will go away.(It will be interesting to see how the parts supply situation holds up in the longer term) This may all be a false impression, but it is consistent with the modern marketing, and general, ethic these days. I might send an email and see what happens just for fun...if I'm a nuisance I might as well push the thorn a bit deeper into their side for good measure!  GN. | ||
| Gordon Norris Frequent User Username: crewes_missile Post Number: 74 Registered: 2-2005 |
Bill, Richard and Robert, Just to let you know, thorn duly thrust to techinfo@bentley.co.uk this morning. Awaiting reply with bated breath when the time zones catch up...will keep all posted with reply (if any)... GN. | ||
| Larry Halpert Prolific User Username: larry_halpert Post Number: 51 Registered: 9-2003 |
My temerature guage before changing the thermostat was about 1/3 of the way up. I lost all heat right away. The old thermostat was a lead plug one and looked like it never was changed. My Spur is an '89. With the new (lead plug) thermostat, it reads almost half. I have lots of heat now, but I don't know what it will read in the hot NY summer. Does the new style brass thermostat still have the "jiggle pin"? Larry tbird@consultant.com | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 636 Registered: 4-2003 |
Thanks, Gordon and Larry. I note from my old thermostat it is marked 88/27 Made In England. According to the book, it should start to open at 80-89C, and be fully open 14.3mm at 99-102C. That's a range of around 10C or 18F. Unlike in my earlier statement on US vs UK thermostats, we must beware. I assume that 88/27 means that nominally it starts to open at 88C, so I don't know what the 27 means. Maybe it's a coincidence, but 2.7" is roughly 70mm. The diameter is 70mm. If Crewe really have dropped the fusible links, and I believe you Gordon, they must believe that the improved radiator and header arrangement of the 20,000-series cars render them unnecessary. Given that there is no bypass valve, unlike on the 6 Cylinder cars, these thermostats are suddenly sounding decidedly generic. For example, I have found new 88C Land Rover thermostats for the 3.5 V8, part number FF001300, advertised new for £2.50.... Worth a look I think. | ||
| Gordon Norris Frequent User Username: crewes_missile Post Number: 79 Registered: 2-2005 |
No reply from Crewe to my email as yet...don't think I should hold my breath!  Richard, looks like alot of the stamped numbers are production related only, possibly QC...please disregard the small "93" I found on top of the new one. It must have been coincidence that it corresponded with the fully open temperature. I have today seen another new one in the possession of my mate with the 96 Bentley, and it has 88 on the bottom and "91" on the top, fresh from a Crewe box. My old one that was in the car has 88/29 on the bottom and on close inspection "9 something" on the top, partially obscured by the first lead plug clockwise from the jiggle pin. The new old style I have has 88/039 on the bottom and "8 something" on the top, again the second digit obscured by the first lead plug. As I said Richard, I'm with you on looking for a generic sustitute, as long as it's completely kocher. There is a ten-fold price difference from the Land Rover part you mention and the Introcar RR price. Will advise further if I hear more from Crewe. GN> | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 639 Registered: 4-2003 |
Gordon, I am very careful with thermostats too. However, if the fusible links are to be deleted, the whole picture changes. My old one has 2-something disappearing under the first link in the same place as your 9-something, so I guess the number means nothing for us to know. RT. | ||
| Gordon Norris Frequent User Username: crewes_missile Post Number: 81 Registered: 2-2005 |
"There was movement at the station.." An email acknowledgement: Dear Mr Norris Your enquiry has been forwarded to our Technicial Department who will respond to you directly in due course. BENTLEY MOTORS LIMITED Crewe, Cheshire, CW1 3PL, England Tel: +44 (0) 1270 255155 | ||
| Robert Wort Grand Master Username: robert_wort Post Number: 156 Registered: 12-2004 |
That's promising Gordon. At least you were acknowledged. | ||
| Gordon Norris Prolific User Username: crewes_missile Post Number: 107 Registered: 2-2005 |
Well, 9 days since my original enquiry to Crewe, and a week since they acknowledged receipt, BUT NO ACTUAL REPLY! I sent a reminder email last night, but find this inexcusible service in this day and age of instant communications. Apart from anything else, it is just plain bad manners, let alone poor PR. Ah well, that's the world we live in today. Unless there's a quick buck in it, nobody actually cares anymore...shame on you Crewe, or rather VW...  Will post further when/if a reply is forthcoming. GN. | ||
| Larry Halpert Prolific User Username: larry_halpert Post Number: 54 Registered: 9-2003 |
Any comparisons done at the local parts store to see which other car uses the same thermostat as the Rolls? Larry | ||
| Gordon Norris Prolific User Username: crewes_missile Post Number: 110 Registered: 2-2005 |
Hi Larry, I've been a lookin', but haven't found anything as yet. I was going to try an online search for some catalogues where hopefully dimensions and specs are listed that may match up. And still no reply from Crewe...probably still trying to work out a way to say they changed it due to economies of scale, but decided to charge us more anyway... And I must apologise Larry, you asked way back does the new one have the jiggle pin....YES it does. If you ignore the colour, it is identical to the original in all dimensions and general design, but has no lead plugs. GN. | ||
| Gordon Norris Prolific User Username: crewes_missile Post Number: 123 Registered: 2-2005 |
A quick update on the thermostat saga: 17 days since I enquired of Crewe. 2 further polite reminders sent by me. Another acknowledgement 48 hours ago from them reads: Dear Mr Norris Please accept our apologies for the delay. We hope to answer for you later today BENTLEY MOTORS LIMITED Crewe, Cheshire, CW1 3PL, England Tel: +44 (0) 1270 255155 Nothing arrived later that day or since... Might send an email to Pischetsrieder at VW...heh, heh, heh... ...and research-wise: I've eliminated the usual suspects as having a suitable replacement-Jaguar, Rover, Land rover - they are quite different. I've looked at alot of VW ones also but they seem to all be the bypass type of thermostat, even going as far back as the late 70's/early 80's. Will keep you all posted on further developments. See Bill, writing to the factory ain't what it used to be....it's a different world. GN. | ||
| Gordon Norris Prolific User Username: crewes_missile Post Number: 131 Registered: 2-2005 |
Finally, after 3 weeks, my original email and three separate reminders since, a reply from Crewe on the thermostat issue, but one which I find disappointing and which really provides no real explanation or reason for change. I've been fobbed off I feel. My original email to them reads: "Greetings from Australia! In 2002, a new thermostat for the 6.75litre V8 was introduced (PG 58252PA) that is backwards compatible to chassis number 20000 cars onwards.(1987 MY) (Cars prior to 1987 must still use the old thermostat UE36600) The service bulletin in TSD 6000 simply states "the specification of the thermostat has been revised to ensure optimum coolant temperature" The new one no longer has the lead fusible links and is brass/plated rather than silver/grey and looks like most other "conventional" thermostats. I realise that running cold can be just as harmful, if not more-so, than overheating under some circumstances, but I always felt the fusible links were a good idea and offered a bit of extra protection from a stuck thermostat. Could the reasons for replacement be expanded upon, as it has become the subject of much conjecture on the RROC(A) forum, and why the pre-20000 chassis number cars MUST use the older thermostat. Any information would be much appreciated. Kind regards, Gordon Norris." Here is the reply: "Dear Mr Norris The reason for the delay (in replying) is that our Engineering department have been looking into whether there is a need to use the lead pellet type of thermostat prior to 1987 as this is old technology. It is looking like a new thermostat will replace it similar to the new one which has been introduced in 2002 for all cars from 1987 MY. However, this has not been officially released yet. We will advise more in due course." YEP! THAT'S IT! To dismiss something for no other reason than it is "old technology" is foolish, but in the context of the ubiquitous wax filled thermostat that is used in virtually every internal combustion engine on the planet is laughable, as that technology itself is some 90 years old! The new thermostat opens faster (see above posts) but otherwise is identical, minus the lead fusible links and hence offers no protection from overheating from a stuck thermostat - the lead link one DOES...old idea, sure, but to me a better one. I think I'll stick to the tried and proven lead link thermostat. ..And the new one costs nearly 50% MORE! WHY, WHY, WHY!!?? (Yes, I know, silly question! $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$) GN. PS. Just one other little query...when the lead links do melt, has anyone actually discovered where the lead blobs finally end up? eg/ do they stay in the thermostat housing? or do they pass into the radiator core and cause any blockage? Just wondered...maybe Bill Coburn or Robert Chapman knows? GN. | ||
| Lluís Gimeno-Fabra Grand Master Username: lluís Post Number: 308 Registered: 8-2007 |
Et bah voila... This was an interesting threat related to my previous question on overhauling the injection system. I could test my old (left, still working) lead-style thermostat versus my new one (right), and may be dut to age, may be due to design there is a big difference in the opening rate: These are the two at 59C: http://i1282.photobucket.com/albums/a537/gimenofl/imagejpg1_zpsafa623b0.jpg All nice and closed... But see at 89C: http://i1282.photobucket.com/albums/a537/gimenofl/imagejpg2_zps32fcb3bb.jpg The new one has about 10-12 mm opening, whereas the old one is about 6-8... From direct observation the difference is quite obvious, so the new style could have a bit more sensitivity. I know there is nothing wrong with out cooling systems, but sometimes I wonder how a modern electric water pump and fan, all electronically controlled would do. Lluís | ||
| Bob UK Unregistered guest |
Lluis, sorry to misspell your name earlier on your injector leak posting. As you say the system as is doesn't have a problem. So modifing is not necessary. If the stat has a jiggle pin which is for venting air from below the stat to the top. Check that it cannot jam the stat moving disk. If it does cut off the Y and throw the jiggle away. If their is no jiggle pin or hole then drill a 3mm hole or smaller to allow air to bleed. I am very cautious with modifying cooling systems because it so crucial to the engine. (Message approved by david_gore) | ||
| Lluís Gimeno-Fabra Grand Master Username: lluís Post Number: 310 Registered: 8-2007 |
No problem, my name has seen worse crimes. I did check that all was free. The increased movement may of course be due to the new thermostat being new, but it was really remarkable. Components are both genuine and purchased from Bentley. | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 3163 Registered: 4-2003 |
The later type without pellets is preferable for cars like yours with a temperature gauge. The lead fusible links are a good idea for those cars around 1968-1977 which have no gauge. The trouble with the pellets is that you cannot see whether they are still intact until your remove the thermostat. If they have disappeared for any reason like overheating shortly due to a coolant leak then the motor will run cool. When these motors run too cold the wear rate skyrockets. The newer thermostat is the best for the later cars, and a bonus is that they cost half as much as the more-or-less obsolete lead pellet type. As always, be prepared for all four thermostat housing cover bolts to shear. No joke, it happens all the time like on my Conti R when I tried to change the thermostat a few months back. Workshops around here are used to rectifying these sheared bolts almost monthly. R. | ||
| Lluís Gimeno-Fabra Grand Master Username: lluís Post Number: 313 Registered: 8-2007 |
They came out at the verge os shearing but they came out in one piece. I changed them already terrible how rusted they were. | ||
| Bob UK Unregistered guest |
Copper slip grease. Assemble joint with gasket gloo put in two bolts then copy slip the other two bolts, then screw them in. Then take out first two and copper slip them. Observe torque setting. These bolts came out ok and nice New ones will make a potential pita into a cake walk. Mine were a bit tight so I fitted new ( well new to my car) bolts and ran a plug tap down. Plug tap is also called the third tap. With flat stat elbows like this one I like to rub it one a flat piece of production paper. The marks left by the production paper grip the gasket and I know it's flat ( flat enough to seal that is). Also where the bolts seat. I like to give that area a good wire brushing and pass a drill through the holes. Leaks aren't allowed. If these bolts shear remove manifold and take to helicoil specialist. (Message approved by david_gore) | ||
| Mark Aldridge Prolific User Username: mark_aldridge Post Number: 189 Registered: 10-2008 |
Bob, it is possible to helicoil in situ, I had to do all 4 on my shadow. Mark | ||
| Quentin Oram Unregistered guest |
My Conti R 1994 ran cool since purchase last year, maybe 1/4 guage on a hot or cold day and oil temp gauge barely any sign of movement, I thought the plugs had melted but It had the new style brass thermostat fitted which I replaced with the old style, it now runs exactly in the centre of the temp gauge and the heater is noticeably warmer and even the oil temp gauge moves up to maybe an 1/8. Presumably the engine is running more efficiently and burning less fuel... Anyway to me at least it seems right now and it didnt before. (Message approved by david_gore) | ||
| Bob UK Unregistered guest |
The optimum temp is 100c. But most cars 90c. The oil in the engine is a major part of the cooling system. The sweet spot figures are 100c 10psi oil pressure per 1000rpm 10 viscosity oil. This is the most efficient you can get cooling and oiling wise. Plus the combustion is better. Ideally for combustion efficiency even higher temp are better but engine damage will occur. This engine will run all day at 90 with brief forays into 100c. Note. Some engine gurus say 0 viscosity. It makes no difference because a fully synthetic oil covers all the bases. You presumed right your engine. Will run more efficiently. This shows up better on long runs. My Shadow when fully warmed up is silky smooth and at idle I cannot feel or hear the engine. This takes 5 miles. (Message approved by david_gore) |
