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rogerch

Water temprature

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Went for a short run into Coffs this morning, reversing back into the driveway, the temp gauge which was only just above 80 (nice) suddenly started flicking erratically almost the full scale of the gauge and the fans came on, in the time it took to reverse in, the gauge had risen 100, and then immediately started coming down again. No other gauges do this, so I can eliminate a common earth issue. I have cleaned the contacts on the temp senders, though noticed the fans do not come on with the air can, but do come on with engine temperature.

I believe the engine temp to be good, even on the cool side, I think the gauge is lying, but the thermo fan switch could be an issue.

Any ideas??????????????


Life is like a sewer, what you get out of it, depends on what you put into it. (Tom Leahrer)

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Hi Roger

The fan relay takes a second feed from the air-con system, so when the A/C compressor kicks in the fans come on too. If the fans come on when the engine temp comes up, but not when the A/C is On then this 'new' problem lies in the A/C circuitry. It should be simple to trace and goes via a diode which is located near the relays in the front hatch - could just be a loose connection or diode fault.

It's on page 13 of your service manual circuit diagrams. I have attached it below and marked the bit you need in red, you will also see from the drawing how the coolant otter switch and the A/C signal come together at the relay. I know how you love electrical faults, so let me know if you need help.

post-5938-0-58413700-1292966656.jpg


Too many Toys are never enough !

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I took the terminals off all 3 of the temp sensors and cleaned them last weekend (one at a time), per chance I got the terminals the wrong way round re-connecting (I don't think I did) but would it make a difference?

Which of the 3 is the gauge, or were does the gauge get it's information from?

OK

Found the gauge terminal, a single terminal near the thermostat (how logical) not in the best of shape, cleaned up now and the erratic behavior seems to be gone.

Possible problem or explanation, when the air-con cuts in I should (at idle) see a slight reduction in RPM, probably sitting idling with the door open I might even hear the compressor cut in.

I cant\'t which leads me top believe the air-con is not working. Fuse 9 is "ACU compressor" 7.5A so I figure that's not the fuse for the air-con compressor, too small, and anyway it's good.

So I'm guessing that the reason the fans are not coming on when I turn the air-con on is the air-con's not working.

So how do I test it ?

GOT IT

Thanks for the drawing Steve, low pressure in the air-con gas, I knew it needed re-gassing but didn't realise there was a low pressure cut out. Shorted the 2 terminals together and on came the fans.

See, who said Roger Harris was lousy with electrics. :animier: :animier: :animier: :animier:

Still say the fans come on too late. So if you find an otter switch that turns on at 88/90, while you're over there, get 2 please. (SJ can get some some but it's a silly price)

Edited by Roger the Dodger

Life is like a sewer, what you get out of it, depends on what you put into it. (Tom Leahrer)

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Good work Roger

It looks like your A/C needs a re-charge of gas. That R134a you have in there tends to leak away more than R12 and it's equivalents due to smaller gas molecules sneaking past the seals in older cars. I bet a recharge will see you right for another year or two, maybe try HR12 instead - larger molecules, less chance of leaking and seems to work better ( in my Esprit anyway ). Pity you are so far away or I could do it for you.

I'm still with you regarding the otter switch, it needs to come on at about 90C in an Australian summer to keep teh coolant temperature in check. Go on, use your heated rear window switch to turn it on manually - you know it makes sense and it'll give you peace of mind when stuck in that once a year traffic jam in Coffs. it's just a cut and splice to one wire and easily reversable.


Too many Toys are never enough !

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Got a diagram ? :hope:


Life is like a sewer, what you get out of it, depends on what you put into it. (Tom Leahrer)

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Hi Roger

Check your email, I have sent you the drawings and details. Page 13 and 30/31 of the service manual electrical section is where the schematics are. Basically you need to remove the HRS relay and link it's 12v coil feed which comes from the HRS switch to the fan relay coil instead. Job done, and that way the HRS switch lights up showing you that the fans are on too !


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Well I finally got round to :-(it's raining today) putting the old thermostat on the stove along with my oven temperature probe. The sort of thing that used to pi$$ my mother off.

Well sure enough it opened pretty much dead on 82, but only just, the temp was up around 90 before it was fully open. So what I don't know is if the water had remained at 82 would the thermostat have continued to open fully ? Trying to regulate the water at a steady 82 is pretty much impossible, so anybody know? :construction:


Life is like a sewer, what you get out of it, depends on what you put into it. (Tom Leahrer)

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Of late it's been 'ot mum. Bloody hot, even for Coffs Harbour, we're talking up toward the ton in Fahrenheit. (Gee I'm glad I got the air-con re-gassed) anyway I found I was loosing water but could not figure out where from. I was loosing about a litre each time I used the car, and getting very erratic and scary readings on the temperature gauge. Each time I'd find the expansion bottle empty, so I'd replace the litre missing from the header, and scratch my head.

Then it dawned on me that it was pushing the water out but not pulling it back on cool down. So I start checking for leaks, culprit was the presure cap on the expansion bottle, replaced, problem solved, no water lose. Bit I'm still getting these wildly varying readings on the temperate gauge. Can anyone tell me how I can test the sender on the thermostat housing, the gauge leaps instantly about 10 degrees in either direction, far too quickly for it to be temperature fluctuation, so it has to be electrical and no other gauge does this.


Life is like a sewer, what you get out of it, depends on what you put into it. (Tom Leahrer)

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Hi Roger

I think the VDO temp gauge sender has is a device that goes from about 20 - 200 ohms, so if you get a 100/120 ohm resisitor from your local Dick Smith or Jaycar store ( only needs to be 1/4 watt ) and connect that instead of your temp sender you will be able to see if the gauge works OK. You could even get a potentiometer about 200/250ohms and try that, turning the pot should make the gauge needle go up and down the scale. That way you can decide whether it's the gauge or sender that has a problem. You will have to connect one end to the chassis witha croc-clip lead or similar and the other to the sender wire.

The sender relies on the sensing tip being emmersed in water to complete the circuit inside the system, so if you have a bit of air in there it could cause eratic readings as the water splashes around. Maybe try burping your system to make sure all the air is out.

Regarding the pressure and blanking caps on the cooling system, I changed mine around to be the same as 'newer' Esprit's with the blanking cap on the plastic expansion bottle and the pressure cap on the metal header tank. I havn't lost any coolant since doing that and it also means the plastic bottle is not under any pressure, it's just a top-up reservoir.

Regarding the outdoor temperature, if the mercury gets above 30C the Esprit and I stay indoors - there's no way I'm going out in that heat unless I really have to. We are both British and were not designed to operate in those conditions. :hope:


Too many Toys are never enough !

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Mad dogs and Englishmen.


Life is like a sewer, what you get out of it, depends on what you put into it. (Tom Leahrer)

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What's one of these 100/120 ohm resistors, Steve, I'm only up to multimeters, and not particularly flash with that.


Life is like a sewer, what you get out of it, depends on what you put into it. (Tom Leahrer)

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Hi Roger

Call into your local electronics store, they are a 10c component. Alternatively i'll pop something in the post to you fi you can wait a few days. I might even have a potentiometer knocking around that I can send you, that way you can test the full scale of the temperature gauge.

post-5938-0-74177400-1296768372.jpg

post-5938-0-68595200-1296768432.jpg


Too many Toys are never enough !

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That's still a bit technical for me Steve, but I do have an update.

Remember I started all this stuff to minimise temperatures and increase boost. Well the weather's cooled a bit, with the new cap I have had to bleed a bit of air out of the system, but the gauge has stabilised some what, but is a lot less erratic.

Now all this attention to detail is paying dividends. I had to go to meeting last nigh, the gauge never went above 90, and coming off the roundabout at the airport WOOOOOOOOOOOOOOsh, I was having to work hard to not brake traction and keep it straight, Cape Canaveral all over, and it just kept boosting, headlights pointing at the stars, what fun.

I think the younger generation should exercise more self discipline and restraint, that sort of conduct wouldn't have been allowed in my day. :gathering:


Life is like a sewer, what you get out of it, depends on what you put into it. (Tom Leahrer)

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Thats good news Roger. I find that if the outside temperature is below 25-29C the temp gauge never goes above 85 and the fans rarely come on, but as soon as the weather gets hotter ( over 30C ) up the gauge comes as the radiator cooling efficiency suffers. The fans still hold it under 90 though when switched on. ( manually ) I reckon bleeding that last bit of air out made a difference, as I posted previously if the sensor doesn't stay submerged it can cause an eratic reading. Look on the bright side, Autumn is just around the corner and you won't have to worry about overheating until next November.

Regarding the Otter switch - Justin just bought a new one from 'Elan factory' in Melbourne, and it seems to kick in at about 90C which is almost 10 degrees before mine does, his overheating problem has gone away now as the fans come on much sooner. I might buy one before next summer, i'll ask justin for the part number.


Too many Toys are never enough !

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Roger,

Reference to the stove testing of the thermostat itself. That is the correct operation of a thermostat. Should just open at the marked temperature and as the temperature rises the thermostat will continue opening. Manufacturers of thermostats state that it should be fully opened about 10 degrees above the opening temperature.

So no worries there. If you need the specific data and resources I could go into my Kindle and find for you the references.

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Bugger, walking back to the car this morning I could see a small puddle under the back. Backed the car up and looked, it was water, only a few drops and not immediately clear where it was coming from.

Temperature still OK, so make a mental note. Same thing at the next stop, then I conclude with relief that it's condensation of the AC compressor.

That works for me until I reakise I didn't initially have the AC on.

Get home eventually temperature still normal, have good look underneath, open up the back and confirm it's the expansion tank, only seeping even under pressure ATM, but obviously will have to come out, which may as well be now as I already have half the floor of the boot out for gear-linkage access.

No biggie I can get it repaired locally.


Life is like a sewer, what you get out of it, depends on what you put into it. (Tom Leahrer)

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Is that the steel reservoir tank, or the plastic expansion tank thats leaking ? I fitted a new alloy tank a few weeks ago ( for fun ) and swapped the caps over so that the new tank is under pressure but the expansion tank isn't ( just like the newer cars have ) all seems OK. You can have my old steel tank if yours is bad, mine just needs a clean up and a coat of paint. Call me santa :santa:


Too many Toys are never enough !

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Thanks for the offer Steve.

Here's my plan, a new alloy one from SJ is just over 200 dollars landed. Can't see me getting out of a repair for less than say around $90, which makes a new alloy one sound like good value. But I need the car and though it's only seeping ATM, it still posses a risk. So Friday I will take it out, clean it up and fibreglass the leaking bit. A free temporary repair until the new one arrives which is usually within the week. :thumbsup:


Life is like a sewer, what you get out of it, depends on what you put into it. (Tom Leahrer)

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Make sure you order the elongated rubber grommet for the level sensor, mine arrived without it so I had to wait another week for one. Also check that the little 'spout' in the neck when it arrives, mine was loose and had to be sealed in it's hole - it was only holding on by one thread. Other than that, it's a good tank. I managed to get to the 3 nuts holding it on using a flexi extension and a 1/4" drive socket from inside the wheel arch body area. No need to remove all that electrical stuff in the black box.


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Thanks for the tip, I've ordered the tank, the grommet and a master cylinder kit (getting a spoungy) Steve tells me I will have to wait for the tank 10-14 days, so good decision to do a temporary fix on the old one, today's job !


Life is like a sewer, what you get out of it, depends on what you put into it. (Tom Leahrer)

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DSC_0604.jpg

Not sure why I've ordered a new one now. :rolleyes:


Life is like a sewer, what you get out of it, depends on what you put into it. (Tom Leahrer)

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Nice job, You could always make it your 2nd sale on Ebay and get some of your $200 back for another job later.


Too many Toys are never enough !

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Has a nasty turn today :shock: I was in my local hydraulic joint, (after master cylinder kit) when the inevitable of "what's it for" I turned and pointed outside, whereupon I saw water dripping from about the midpoint, sort of water pump area, "Oh 'uk it". I've had my fill off water/cooling issues of late. Anyway car starts up, temperature normal, next point of stop check again, nothing, temperature again normal. Now straight home, better safe that sorry. Stop ion the drive, again no trace of water. Translucent header tank shows normal level.

At this point, I'm figuring it was raining bloody hard yesterday, so what I was seeing was some residual water that had been caught some where, and no cause for alarm. I think I'm getting paranoid. :w00t:


Life is like a sewer, what you get out of it, depends on what you put into it. (Tom Leahrer)

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Um,,,, yes. (now that I come to think about it) :whistle:


Life is like a sewer, what you get out of it, depends on what you put into it. (Tom Leahrer)

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