andyborris
Posted a lot
Freedom is just another word for nothing left to lose.
Posts: 2,158
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Sept 30, 2016 17:43:35 GMT
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Are you sure it's the 'stat and not your test method/measuring device? At 98ºC in a saucepan the water will actually be starting to boil. The Wahler units (Audi use em too, and yes, stupidly expensive) are about the best and usually last at least 5 or 6 years. All the ones I've had fail have gone the other way and either open too soon or don't fully close. My TDI doesn't generate much waste heat so in the winter even a small gap in the thermostat means it doesn't warm up properly. Nick Pretty sure it was 98c, that's what the gauge said in the engine, and what the cooked chicken thermometer said in the pan (water just starting to bobble). I understand that the engines temp isn't really 98c because of the 7lbs pressure it's under, but that's the temp the engine "thinks" it's at! I also think the chicken thermometer is accurate, I checked it with an infra red thermometer gun and the potential for lawsuits caused by undercooked chicken helps ensure accuracy! Passed for breath on this now, waiting for parts and just relocated to a garage in the block where I live, so sorting and soon to be Ebaying!
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Sept 30, 2016 19:03:04 GMT
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The temperature doesn't change because it's under pressure, it just not so near boiling as the pressure raises the boiling temperature.
Sounds like the testing is correct considering agreement from two methods.
Nick
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1967 Triumph Vitesse convertible (old friend) 1996 Audi A6 2.5 TDI Avant (still durability testing) 1972 GT6 Mk3 (Restored after loong rest & getting the hang of being a car again)
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Sept 30, 2016 19:25:08 GMT
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Do you have a build thread anywhere? Love the sound of this project.
As an aside, this generation of BMW i6 do run very hot by design so wouldn't worry too much.
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Sept 30, 2016 22:15:37 GMT
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The temperature doesn't change because it's under pressure, it just not so near boiling as the pressure raises the boiling temperature. Sounds like the testing is correct considering agreement from two methods. Nick That is what I meant.
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andyborris
Posted a lot
Freedom is just another word for nothing left to lose.
Posts: 2,158
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Just checked the new 88c stat and it starts to open at 94c! And is fully open at 96c, so nowhere near 88c then.
I think I've now tried every brand of stat and none of them do what they're supposed to do, open at 88c.
I think I'll fit this one, getting fed up with this saga now.
Even with the 98c stat fitted the rad fan maintained the temp at 98c, even after about 5 mins at 3000 RPM and 2 hours idling.
Or rather, I assume it did. Assuming the stat opened at 98c, as shown on the gauge and with the fan running the temp didn't climb. The bottom rad hose felt warm, but not hot, much cooler than the top hose (this feeling confirmed by temp gun).
The rad had parts that felt cold to touch. So perhaps the fan was knocking the temp down and the stat (doing it's job!) pulled the temp back up to 98c.
Opinions please.....and another question, the pressure in the cooling system just raises the boiling temp, so 98c is still 98c, just steam won't appear till the gauge hits above 100c?
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Bolf
Part of things
Posts: 507
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Just FYI , the bmw rad caps are rated just over 2 bar so the system on a normal car would sit at 106 deg c
I've had a lot of BMW and a lot of people I know have struggled with engine swaps and running temps/boiling over until I told em to find a higher pressure rad cap.
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colnerov
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Hi, If you've got cold spots on the rad that indicates it's blocked in places.
Colin
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andyborris
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Freedom is just another word for nothing left to lose.
Posts: 2,158
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Just FYI , the bmw rad caps are rated just over 2 bar so the system on a normal car would sit at 106 deg c I've had a lot of BMW and a lot of people I know have struggled with engine swaps and running temps/boiling over until I told em to find a higher pressure rad cap. That's interesting, the present cap is a 7lb (.48 bar), I'm wary of going higher, not sure if a 50 year old Triumph heater matrix will stand 2 Bar. The car hasn't boiled yet, it did on the previous system, but that was caused by a wiring fault! This whole thread stems from my belief that the very expensive BMW OE stat was opening at 88c, instead and like every aftermarket stat, it opens at 98c. Not sure what, if anything, I can do about the lower pressure cap.....
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andyborris
Posted a lot
Freedom is just another word for nothing left to lose.
Posts: 2,158
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Hi, If you've got cold spots on the rad that indicates it's blocked in places. Colin Sorry Colin, didn't phrase that very well! Not cold in places, but has even "fade" from hottest point (inlet) to coolest (outlet)! Pretty sure it's not blocked, it's a brand new aluminum one that's meant to have a higher capacity and when I tested it, it held more water than a new plastic one. I think because I got readings that were very unexpected, I've maybe overthought and worried unnecessarily. All the time the car was running, both at idle for about 2 hours and the 5 mins spent at 3000ish rpm, the temp stayed the same with the fan running, the 98c the stat was opening at. I'm going to fit this new stat, it does open at a slightly lower temp and the fan switch point of 95c in the bottom hose should cool the rad before any damage is done, fingers crossed!
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ChasR
RR Helper
motivation
Posts: 10,192
Club RR Member Number: 170
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Oct 10, 2016 12:58:46 GMT
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For this reason I fitted a genuine BMW thermostat, which is made by WAHLER. Yes they are £30 but for me, life is too short to be chasing cooling problems. On other cars (Triumph Spitfire, Peugeot 106 etc.) I've had the opposite problem with pattern items. They open too soon! I think the Wahler ones are £15 delivered. retrorides.proboards.com/thread/173380/1997-323i-coupe-winter-smokerYup, I once owned a car (and it wasn't the Stag amazingly!) that almost always had a cooling issue monthly! While it never overheated another hose was always going, the temp was until a thermostat change never stable etc. etc.
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andyborris
Posted a lot
Freedom is just another word for nothing left to lose.
Posts: 2,158
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Oct 10, 2016 18:41:39 GMT
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Almost agree with you, after stats that were opening too high, I stumped up for a BMW oem part and I know it's not dodgy ebay part, because I stood in the stealers and cried as I paid! But that's the one that's just been pulled and caused all this fuss in the first place! It was a open at 88c one when it was fitted into the engine, but now it's a little older, it opens at 98c! It's almost like as it got older, it decided to live somewhere warmer, like a lot of people do. Looking back on this issue, I'm more and more inclining to the opinion that I was misdirected into thinking I had a problem, when I don't. The engine maintained its temperature easily, it's just that I expected 88c, not 98c. Thanks for all the advice everyone, it's been a wild ride. Been trying to add a pic of a cool BMW, can't get it to stick and me dinners ready, sorry!
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Oct 10, 2016 19:58:34 GMT
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Idleing for 2hrs and fast Idle for however long then only seeing 98 with fan constantly running. Tells me you don't have a problem.
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andyborris
Posted a lot
Freedom is just another word for nothing left to lose.
Posts: 2,158
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Oct 19, 2016 14:05:57 GMT
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Went for a drive today with the new stat fitted, this is a 88c one that opens at 96c!
Temp never dropped below 100c, (measured in top hose) at one point almost reached 120c while driving slowly, mostly around 105/110c while driving at about 50ish.
Header started "gurgling" and dumped most of the coolant when the cap was removed. Fan never came on, so assuming the sender switch is OK, the bottom hose never hit 95c and the rad doesn't feel hot at the outlet, warm but not hot. there is a temp change across the rad.
Guessing it's one of 2 things, a bad air lock that's now cleared (I should be so lucky! @ K.Minogue) or I've spent 2 years fitting a engine with a blown head gasket, the same as the old engine!
Opinions and sympathy please..........
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colnerov
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Oct 19, 2016 14:14:46 GMT
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Hi, How are you measuring the temperatures? The temperature gauge in the dash is not a precision instrument, even with a matched sender. Of course the coolant will be ejected if you take the cap off when it's hot because in the time honoured phrase "They all do that, sir".
With the temp change across the rad and your assessment of the outlet pipe temp and not boiling up when driving, I would say it's working OK.
Colin
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Last Edit: Oct 19, 2016 14:18:17 GMT by colnerov
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andyborris
Posted a lot
Freedom is just another word for nothing left to lose.
Posts: 2,158
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Oct 19, 2016 14:23:12 GMT
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Colin, thanks for trying to cheer me up!
The gauge has been tested and found to be less than 1 degree out at 100c, not so accurate at 50, but I think that's not so important.
This was much more than the usual "they all do that Sir", most of the water jumped out, even hit the boot, that's how high it went! This was accompanied by steam and spit out of the overflow pipe on the header and a fantastic gurgle before the cap was removed.
I'm about to hit Ebay for an engine, wonder if a 330i will bolt onto a E30 gearbox.......... unless anyone on here has a good M52?
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Last Edit: Oct 19, 2016 14:24:00 GMT by andyborris
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slater
Club Retro Rides Member
Posts: 6,390
Club RR Member Number: 78
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I've been reading back but may have missed.
What's the actual problem? It boils up? Or are you just chasing temp readings?
If you remove the cap when hot it will fire all its coolant over the car. Don't ever remove the cap when it's hot! The heat soak off the engine is enough to boil water even when it's not running and if you dump the pressure it will flash boil and explode all over you.
Under pressure it can go over 100c without boiling. You will see the temp rise to near 120c sometimes before it starts to boil, that's the point of a pressurerised system.
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andyborris
Posted a lot
Freedom is just another word for nothing left to lose.
Posts: 2,158
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Quick recap and to get it clear in my head!
Fitted new temp gauge, run unknown engine and the temp climbed to 98c but stabilized there.
I was expecting 88c because I had a 88c stat fitted.
Pulled the stat, tested it and it opens at 98 not 88.
Gave up trying to find a stat that opens at it's stated temp, fitted new 88 stat that opens at 96.
Run engine again, temp climbed to over 100. But fan didn't activate, fan switch point is 95 on & 90 off, fan works when switch is bypassed, new sender unit fitted.
Presume that this means coolant exit temp lower than 95.
Went for a gentle drive, (OK, with a 5 second blast included!) temp reached 120 at on point, never dropped below 100.
Lots of gurgling in header tank and the aforementioned spit out. Water didn't actually feel that hot, but it was under lots of pressure. Top hose was touchable, bottom hose warm.
The temp gauge is in the top hose and seems pretty accurate at 100c, the fan switch is in the bottom hose. The cooling system has much the same flow system as in a BMW car, the header tank is relocated, but the pipework is the same. Header tank is higher than the engine and the aluminum Golf rad is new and unblocked. It also has a air bleed pipe at it's top that vents into the header tank.
Have ordered a gasket sniff tester and will go from there. I think exhaust gas is both heating the water and pressurizing it.
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andyborris
Posted a lot
Freedom is just another word for nothing left to lose.
Posts: 2,158
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Also when I run the engine without the rad cap, it blows water out of the header tank. The header tank is empty after a few seconds after the stat has opened.
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Oct 20, 2016 12:52:02 GMT
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Also when I run the engine without the rad cap, it blows water out of the header tank. The header tank is empty after a few seconds after the stat has opened. If it's doing this cold (or cool) it does sound a bit head-gasket-ish - can you smell exhaust from the cap? If only when hot I do wonder a bit about whether your pump is pumping anything (running wrong way, no blades on plastic impeller etc) or whether there is some peculiarity of the piping layout (2.8 BM lumps in T2000s being moderately non-standard) which is causing in issue. IIRC it did work ok to begin with - did you change anything or did it just take sick? Nick
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1967 Triumph Vitesse convertible (old friend) 1996 Audi A6 2.5 TDI Avant (still durability testing) 1972 GT6 Mk3 (Restored after loong rest & getting the hang of being a car again)
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andyborris
Posted a lot
Freedom is just another word for nothing left to lose.
Posts: 2,158
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Oct 20, 2016 13:22:24 GMT
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The first engine boiled on a very hot day in Paris 2 years ago, (keep trying to post a story, with pics, of that, keep failing!)
This was caused by a wiring problem, that switched the rad off, by the time I noticed, the damage had been done.
Before this, it had been fine. The pipe layout is more or less the same as in the BMW.
A new (to me) engine was acquired, that neither me or the seller had seen running! I became unwell and it sat in the garage for 18 months+. Then rather then just refit the engine, I changed the layout slightly.
A new aluminum Golf GTI rad was fitted in place of the OE style BMW one, this fitted further into the nosecone, allowing me to (a) fit a fan behind the rad and (b) remove the rad without needing to take out the engine first!
The Golf rad has it's inlet and outlet on the same side, the BM one had opposite top and bottom. This means a longer top hose by about 3 inches.
The new rad has a larger surface area and holds a little more coolant, apart from that nothings changed.
But I've got a plan, 1st some coolant/exhaust gas check stuff to test and 2nd a new engine.
Found a low mileage (61K) for £275 to my door, with a warranty and will concentrate on getting the car MOTed and on the road. I'll have a replacement engine ready to go in, or a spare stored in my new BIG garage for whenever!
It seems like only yesterday, e36's could be brought for £50 and you drove it home, now £1500 and climbing, the engines used to be everywhere, now it's M54 engines.
Was tempted by a 330i engine, 230ish horsepower fun, but it'll be a lot of work on the electronics, drive by wire throttle etc., I want to drive the car, not spend another year working on it.
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