Water temprature

[rogerch]

At what temperature is the thermostat supposed to open.

It seems mine is getting a bit hot, up in the 90's, before it opens, it cools down to normal quickly enough, but this is a new occurrence.

I'm going to replace the thermostat but I don't know what temperature to get ?

Roger

While we are about it, if I were to use "Water Wetter" coolant this time, what ratio should I mix it at, ie how much do I need for a 7 litre cooling system?

Edited October 21, 2010 by Roger the Dodger

[Advantage]

82 degrees seems to ring a bell.

[Rich H]

Depends on what thermostat is fitted, I'd have thought that a colder thermostat might be a good idea in Australia?

[rogerch]

Thank you kind sir, at the risk of,,,,,,,,,,,,,,,, what's the diameter of the thermostat, or where can I find out before I remove the old one.

[Rich H]

If I remember I'll check my old one later on if you don't get an answer.

I'd think a 75 degree thermostat assuming it's as hot over there as I think it is....

[Jonathan]

92 is the fans, the regulated temp of my car is about 82-83 so Gman could be right...must be right

Dont og on the dashboard for any clues for gawd sake !

[Vulcan Grey]

USE 82C ONLY!

The computers in these cars require a certain temperature range to function correctly! A colder thermostat will cause the car to limit boost and the car will not run correctly.

BTW, I had to change my thermostat recently, I figured out a great way to do it without replacing all the coolant or spilling a drop.

my car was running a little hot, ~90C, in normal traffic, and only getting down

to 82C above 70mph with no boost. Any boost and the temp would almost climb

linearly with the boost gauge.

I ordered a new thermostat from JAE, but I had just rebuilt my engine and didn't

want to drain the coolant. I know I should have replaced the thermostat when I

did the rebuild, that one was ~9 years old IIRC.

I figured out how to drain the coolant without spilling a drop, just enough to

make it so that opening the thermostat housing only released a few drops!

1)leave the coolant header tank cap on.

2)clamp the overflow tube just at the coolant header tank.

3) remove the bleed hose from the waterpump crossover pipe above the front of

the engine. I removed it from the coolant tank and left it on the pipe.

4)place another hose on the coolant tank where the bleed hose went, put a hose

clamp on that and point it in a gallon jug.

5)using an air compressor, put about 10 psi of air into that bleed hose to force

the coolant through the system and out of the thermostat housing (one of the

highest points).

I drained about a gallon this way and the thermostat housing just had coolant in

the lower half, below the thermostat level. No splash under the car when I

pulled the housing apart.

The thermostat is Lotus only, I bought mine from JAE in California.

Edited October 21, 2010 by Vulcan Grey

[Rich H]

That is a good point....

[Advantage]

Part number: A907E6046Z, Thermostat 82°C, All. and is available via the TLF Shop.

HTH.

[rogerch]

Thank you gentlemen, original only, that's the clue, research has disclosed the are 2, one standard 82 and another for hot climates 74, so I'm going to order a 74. It does get hot here.

If it then too cool, it's no biggie, just get an 82. (might even treat myself to a new gasket)

[Rich H]

As above: if your car doesn't get to temp then the ECU will get the hump and think you are still on warm up.

[rogerch]

My car's an 88 Stevens, carb version, no ECU. It may still get the hump, and I have to go back to the 82, but it won't damage anything to find out. I'm planning a trip in January/February which will take me way out west, those long dusty outback roads, (tarmacked) it can get bloody hot out there, like 10-15 c hotter than here on the coast, and you wanna believe I'll have the air-con on.

[Advantage]

Ahh yes, a carby car can have A075K0121F fitted if it's going to be used when the sun is out. The later ecu cars don't require such pandering...

(If you're doing a dusty road trip, it might be worth packing a couple of spare air filters too)

[rogerch]

Good point, I'll take my trusty K&N cleaning kit. always sounds a bit shriller after a clean.

[Rich H]

Carbs won't give a toss - fit the cooler one!

[rogerch]

74 degree thermostat on it's way, not sure when doc will let me fit it, but.

Still looking for the ratios if go to "Water Wetter" as a coolant additive, I think 1 bottle will do the job on an Esprit cooling system, looking for confirmation.

[sailorbob]

Different makes of 'water wetter' require different mixture ratios; if it doesn't say it on the bottle then the manufacturers website will often have it.

[Mike6]

Not true, my car is the same as Rogers and the thermostat was sticking open. Had a hell of a problem with hardly any boost, in fact I noticed this first. Put in the correct 82 degree thermostat and instant improvement. I really wouldnt mess around with anything cooler, the turbo will not like it

[rogerch]

Well the new thermostat arrived a couple of weeks ago, but due to surgery it got put off until this weekend.

I put a board over the engine and folded a couple of blankets over it so I could lie on it , not too bad.

The first bolt came out no drama, the second occasioned some concern, reading threads about sheered bolts, but came out OK, with a bit more elbow.

The existing thermostat looked in perfect condition (I must chuck in a saucepan with a thermometer, see what temp it does open at)

The new one 74 degrees, did not have a bypass/bleed hole which was a concern as I have experienced bleed issues with thermostats without, so I drilled one, I'd love to hear Sparky's opinion on that, but it's done now.

Cleaned the bolts. coated them with Cooper-Eze, new gasket, back together no issues, no, never, there's always one, the hose clamp stripped, puny looking thing anyway, replaced with a real one, job done.

I've only driven locally, but it seems run about 2 degrees cooler all up, the main issue was bringing the temperature back down to 82 after traffic where it may build up to the low 90s.

So we'll see what it does down to Port Macquarie later this week.

[cjtpb13]

Roger,

Met with a specialist in coolant systems and their engineers several weeks ago. We had a discussion about thermostats and he said if they run into a situation where there is no bleed hole that they drill a small one in.

Glad to see that you are up and about and working on the Esprit.

[rogerch]

Still getting this spike in temperature, so a couple of questions,

1 At what temperature are the fans supposed to come on ? (88 carburettor)

2 which of the 2 switches in the water down pipe is it ?

Sorry I know that's a bit lazy, but I'm not fully healed from the surgery yet, and don't want go crawling over it.

[stevem]

Hi Roger

It's the top switch that points towards the drivers side of the car, the other two point to the rear of the car. It switches on at about 95C, which I find is about a minute after you start panicking when sat in a traffic jam during summer. I have now rewired the heated rear window relay to switch the fans on, so pressing the heated window switch turns on the fans mnaually. From March - October I find there's no issue and the fans rarely switch on, but during the hotter months I always turn the fans on myself as soon as the traffic slows down - the gauge never goes above 90 when used in this manner.

I think the ideal solution would be to fit an otter switch that turns on at 88/90. Finding one might be an issue though - but if you do let me know and I'll have one too. If you can find some in the UK let me know and I will bring a couple back with me in a few weeks time.

[rogerch]

There's somethin' weird going on here. It's still doing exactly what it was but acording to the gauge about 2 degrees cooler.

It's telling me something because at high temperatures I have more oil pressure and also the desired improvement in boost. (that's what I was looking for, and why I went to a cooler thermostat)

So the next thing is check the accuracy both of the gauge and the temperature switch for the fans.

[Mike6]

Roger

I think you have got this about face. When my thermostat stuck open on my carb turbo I was getting hardly any boost and the temperature gauge was showing a very low temp - cannot remember exactly what. I researched before buying a new thermostat and read that you should not put in a lower temp thermostat since the water will not get to the required temperature to operate the boost properly. You should stick with the recommended thermostat since the boost reaches maximum efficiency a few degrees below this. If you put in a cooler thermosat you will not get the required temperature for the boost.

[rogerch]

First thing to bear in mind is we get temperatures up 1n 100's on your scale, at this time of year as a daily occurrence.

On inspection the old thermostat was in good shape and functioning correctly. As is the new one, I'm getting all the old readings on the gauge less 2 degrees, that includes the initial spike up 98-100. However the oil pressure does not drop as much at operating temperature, indicating the oil is not getting as hot. I'm also getting more solid boost, again indicating lower temperature.

So now I have to draw the conclusion that the gauge is lying to me, and the fan not coming on as soon as I would like, ie I would like it coming on at 90. I'l inspect and clean the terminals first, probably get a (hot) fan switch (which are available for hotter climates) and go from there.